ROOTS AND TUBERS IN :

OVERVIEW AND SELECTED RESEARCH PAPERS  II III 

Edited by:

Robert Aidoo Department of Agricultural Economics, and Extension, University of Science and Technology (KNUST), Ghana

Jacob K. Agbenorhevi Department of Food Science and Technology, Kwame Nkrumah University of Science and Technology (KNUST), Ghana

Faustina D. Wireko-Manu Department of Food Science and Technology, Kwame Nkrumah University of Science and Technology (KNUST), Ghana

Arne Wangel National Food Institute, Danish Technical University (DTU), Denmark

N Y A N KNUST

S

AP C W C S ANE NO  IV

Copyright © 2019 by College of & Natural Resources All rights reserved. No part of this publication may be reproduced, distributed, or transmitted in any form or by any means, including photocopying, recording, or other electronic or mechanical methods, without the prior written permission of the copyright owners Printed in Ghana At KNUST Printing Press KNUST, PMB, Kumasi V

Contents

Acknowledgement...... ix Forward...... vii

ROOT AND TUBER IN GHANA - AN OVERVIEW...... 1

THEME I:

MARKETING, VALUE CHAINS, ECONOMICS AND EXTENSION ISSUES IN THE GHANAIAN ROOT AND TUBER INDUSTRY...... 23 Structure, Conduct and Performance of the Gari Market in Mampong and Techiman Municipalities in Ghana...... 24 Trust, Governance, Upgrading and Market Power in the Value Chain of Southern Ghana...... 45 Overview of the Sweetpotato value Chain in Ghana...... 80 Resource-Use-Efficiency in Production in Pru District of the Brong Ahafo Region, Ghana...... 102 Consumers’ Perception and Willingness to Pay for Cassava- Non- Alcoholic Beverage (Bansu) in the Kumasi Metropolis...... 123 The Effect of Training on Extension Delivery and Performance of Agricultural Extension Agents (AEAs) under RTIP...... 143 An Evaluation of the Cassava Value Chain in Ghana...... 167

THEME II:

FOOD SCIENCE AND TECHNOLOGY RELATED ISSUES IN THE GHANAIAN ROOT AND TUBER INDUSTRY...... 204 Value Addition Interventions along the Root and Tuber Food Supply Chain...... 205 Enhancing the food applications of cocoyam (Xanthosoma sagittifolium): Deductions from a three-year study...... 243 Orange-fleshed sweetpotato composite bread: The nutritional and economic potential...... 268 VI

Shelf life extension and sensory properties of orange-fleshed sweetpotato using pre – and post-harvest techniques...... 284 Protein and Beta-carotene in -Sweet Potato Fermented Composite Flours..... 308 Utilization of cassava peels as feed for ruminants in Ghana: A review of alternative methods of improving their nutritional value...... 332 Product development from Yam in West Africa: market potential and challenges..... 351 The student breakfast foodscape on the campus of Kwame Nkrumah University of Science and Technology, Kumasi, Ghana ...... 373

THEME III:

PRODUCTION, PROCESSING AND MECHANIZATION ISSUES IN THE GHANAIAN ROOT AND TUBER INDUSTRY...... 384 Influence of Fertilizer Application on Postharvest Storage of Whiteyam Tubers...... 385 Biocontrol of Meloidogyne spp. using Arbuscular mycorrhiza in root and tuber cropping systems...... 392 Mechanisation of Cassava (Root and Tuber Crops) Production in Ghana...... 413 Eco-design options for processing gari in Ghana...... 443 VII

Forward

Root and tuber crops (yam, cassava, cocoyam and sweetpotato) provide the greatest opportunity for long-term poverty alleviation and food security in Ghana than any other group of staple foods produced in the country. Markets for these staple food crops are rapidly changing due to new consumption patterns and dynamism in their production and distribution systems. Value chains of these root and tuber crops present opportunities for employment generation and improved livelihoods, especially for women and youth, in Ghana and other producing regions in West Africa. Scientific investigations into various aspects of primary production, marketing, extension, processing, value chains and value addition, as well as consumption of root and tuber crops have been undertaken by different experts at different places across different time horizon. In spite of this, a huge body of scientific knowledge on roots and tubers remains largely unpublished and inaccessible to the scientific community and players in the policy arena. Those research outputs that have been published are also scattered in different journals, institutional libraries and online portals. Currently, there exists no single published book that contains information exclusively focusing on root and tuber research works in Ghana. The DANIDA Root and Tuber Value Chain Project in Ghana (2013-2017) decided to compile and publish this book as its contribution towards bridging this information gap in Ghana. The book provides a broad overview on root and tubers in Ghana and presents specific research papers that focus on primary production, marketing, value chains, extension, processing, value addition and new product development, as well as consumption of different root and tuber crops. With contributions from seasoned researchers and academics from universities and research institutes in Ghana and beyond, this book takes a holistic value chain approach and touches on key aspects of all the roots and tuber crops in Ghana. It is aimed at providing information on the current state of the art as far as root and tuber research in Ghana is concerned. VIII

It is my hope that the contents would serve as inspiration to researchers to identify gaps to inform further research in the root and tuber sector. Also, insights from the papers in this book are expected to inform policy dialogue in Ghana in our effort to strengthen root and tuber value chains for job creation, inclusive growth, food security and sustainable development. Professor Robert C. Abaidoo Director, Office of Grants and Research (OGR), Kwame Nkrumah University of Science and Technology (KNUST), Ghana

Former Provost, College of Agriculture and Natural Resources, Kwame Nkrumah University of Science and Technology (KNUST), Ghana

N Y A N KNUST

S

AP C W C S ANE NO IX

Acknowledgment

The publication of this book was made possible through the financial support of the Danish Ministry of Foreign Affairs under its three year South Driven Development Research Project funding. In 2012, KNUST was awarded funding through Danida to undertake various research activities aimed at strengthening the root and tuber value chains in Ghana. KNUST partnered with a consortium of three Danish Universities (DTU, AAU and UCN) to undertake various field surveys and capacity building including the training of two PhDs (one in Food Science and one in Agribusiness Management) and five Master of Philosophy students in Agricultural Economics, Food Science and Business Management. The financial support and technical assistance received from Danida and the Danish partners are sincerely acknowledged. The contributions of Professor Arne Wangel (DTU), Nielson Thokild (AAU), Anne Zakaria Lassen (UCN), and Olav Jull Sorenson (AAU) are deeply appreciated. Contributions of KNUST scientists like Professor Ibok Oduro, Professor Robert C. Abaidoo, Dr. Kwasi Ohene-Yankyera and Professor (former Vice Chancellor – under whose tenure the project was won and implemented) are deeply appreciated. Contributors and Editors of all manuscripts published here are very much appreciated for making this book a reality.The support provided by all the research team members and students on the Danida Root and Tuber Value Chain Project as well as all actors in the value chains of the four root and tuber crops who contributed to the success of the project are duly acknowledged.The support services rendered by Mr. Stanley Boakye-Achampong in managing the Danida Root and Tuber Value Chain Project in Ghana, and particularly in compiling the manuscripts for this publication cannot be underestimated. His efforts are greatly appreciated. Finally, the staff of the Office of Provost of College of Agriculture and Natural Resources, including Accounting and Finance Officers, who manged the project resources efficiently are duly commended for their dedication to duty. X 1

ROOT AND TUBER CROPS IN GHANA - AN OVERVIEW

Aidoo, Robert; Boakye-Achampong, Stanley; Wie, Prosper; and Appiah, Boakye Gifty Department of Agricultural Economics, Agribusiness and Extention, Kwame Nkrumah University of Science and Technology (KNUST), Kumasi-Ghana

INTRODUCTION Africa ranks first in the share of the production of roots and tubers in Roots and tubers belong to the class of the world, accounting for about 70.3%, foods that provide energy in the human followed by Asia, America, Oceania diet in the form of carbohydrates. The and Europe which account for 15.2%, terms refer to any growing plant that 10%, 4.3% and 0.3% respectively stores edible material in subterranean (FAOSTAT, 2015).The production of root, corm or tuber. The common root root and tuber crops in Ghana gradually and tuber crops in Ghana are yam, increased from 10.2 Million in 2000 to cassava, cocoyam and sweetpotato. 17.0 Million in 2013 (ibid). The growth Until recently, policy makers and is as a result of expansion in acreages researchers had paid very little attention rather than increase in productivity to these crops, as most of their efforts or yield. According to GSS (2014), were concentrated on cash crops and Ghana’s roots and tubers contribute the more familiar grains (Aidoo, 2009). about 50% of agricultural GDP and are This was so because, root and tuber produced by about 55% of farmers in the crops were previously regarded as food country. The resistance to drought and mainly for the poor. This misconception adaptability to marginal environments lingered for so long because of the initial and poor soils give root and tubers lack of appreciation of the number of a great potential in contributing to people who depended on these crops, household food security. and the number of lives they have saved Figure 1 shows the land area put during famine and periods of natural under different root and tuber crops disasters. production in Ghana from the year 2000 2 ROOT AND TUBER CROPS IN GHANA - AN OVERVIEW

to 2010. Cassava is seen as the root and 2011).According to MOFA (2012) the tuber produced on a larger area of average yield levels for all root and land, followed by yam and cocoyam. tuber crops in Ghana are low and well There have been steady increases in the below attainable levels (Figure 3). area of cultivation for all crops over the Current yields are estimated at 28%, years. In terms of annual production 31%, 81% and 19% of the potential measured in metric tonnes, cassava is achievable yields of cassava, yam, again the largest produced root and tuber cocoyam and sweetpotato respectively. crop in Ghana with a yearly production These yield gaps highlight the need of over 10 million Mt (Figure 2). In for primary producers to become more 2008, when disease resistant and high productive and efficient in order to yielding varieties were introduced, the derive full benefits from the root and annual production levels increased to tuber industry. about 14 million metric tonnes (MOFA,

Figure 1: Land area cultivated to main Root and Tuber crops in Ghana (‘000Ha)

Source: MOFA/SRID, 2011. ROOT AND TUBER CROPS IN GHANA - AN OVERVIEW 3

Figure 2: Production of Roots and Tubers in Ghana (2000 to 2010)

Source: MOFA/SRID, 2011. Figure 3: Productivity gap of Roots and tubers

Source: MOFA/SRID, 2012. According to Aidoo (2009), the isolate the various root and tuber crops tendency to treat roots and tubers as as individual food crops for critical undifferentiated commodities has for analysis. This is necessary to ensure that some time now obscured their varying policy recommendations emanating uses and performances. It has also from such studies are targeted at specific hindered analysis of their individual root and tuber commodities instead roles in the global food system, clouded of broad generalizations which hardly understanding of their future prospects, work. and handicapped formulation of Yam appropriate policies to exploit their Yams (Dioscorea spp.) are annual or unrealized potentials. Therefore, it is perennial climbing plants with edible imperative for research scientists to underground tubers. Yam belongs 4 ROOT AND TUBER CROPS IN GHANA - AN OVERVIEW

to the genus Dioscorea (family originated from South East Asia. It is the Dioscoreaceae) and only about half- species most widely spread throughout dozen of the estimated 300-600 the world and in Africa, it is second species available are grown for human to white yam in popularity. The tuber consumption; some are grown for shape is generally cylindrical, but can medicinal purposes. Yams originated in be extremely variable. The tuber flesh the Far East and spread westwards. They is white and “watery” in texture. have since evolved independently in In Ghana, yams are produced in the Eastern and Western Hemispheres, all regions except the Upper East and and today yams are grown widely Greater Accra Regions. Brong-ahafo throughout the tropics. In the West and northern regions are the most African yam zone, which is the principal important yam producing regions in producer on a global scale, white yam the country (Table 1). In West Africa, (D. rotundata), water yam (D. alata), Ghana is second to Nigeria in terms and yellow yam (D. cayenensis) are the of yam production. However, Ghana most common species. White yam (D. is the leading expoter of yams in the rotundata) originated in Africa and is the world. This emphasizes the importance most widely grown and preferred yam of the crop not only for household food species. The tuber is roughly cylindrical security but also in terms of its foreign in shape, the skin is smooth and brown exchange earning potential for the and the flesh usually white and firm. A country. large number of white yam cultivars Yam is a very important food exist with differences in their production commodity in the food basket of and post harvest characteristics. Yellow not only rural households but urban yam (D. cayenensis) derives its common households in Ghana as well. On the name from its yellow flesh, which is average, 12% of the food budget of a caused by the presence of carotenoids. typical urban household in Ghana is It is also native to West Africa and very spent on yam products (Aidoo, 2009). similar to the white yam in appearance. The crop is even more important to Apart from some morphological low income households as they devote differences (the tuber skin is firm and a larger proportion (12-16%) of their less extensively grooved), the yellow food budget to yam compared to high yam has a longer period of vegetation income earners who spend less than and a shorter dormancy period than 10% of their food budget on yam and white yam. Water yam (D. alata) yam products. Yam also constitutes ROOT AND TUBER CROPS IN GHANA - AN OVERVIEW 5

about 13% of the away-from-home from home, yam is an important food food budget of urban dwellers in Ghana. commodity in Ghana. Implying that, whether home or away

Table 1: Yam Production Statistics across all Regions in Ghana Production Figures (MT) Area Cropped (Ha) Regions 2014 2015 2014 2015 Western 94926.86 97774.66 12480.00 12480.00 Central 14769.27 15064.66 2759.80 2759.80 Greater Accra 0.00 0.00 0.00 0.00 Volta 494608.95 519339.40 30591.00 31028.00 Eastern 823191.30 847887.04 40262.00 40700.00 Ashanti 521345.50 536959.32 34038.20 34474.89 Brong Ahafo 2416990.00 2425508.0 140410.00 140847.0 Northern 2169542.88 2235723.0 136131.27 136568.0 Upper East 0.00 0.00 0.00 0.00 Upper West 583515.10 617867.00 31340.00 31340.00 Ghana 7118889.86 7296123.0 428012.27 430197.7

Source: MoFA (2016). Yams store relatively longer in Southeastern Nigeria, the meals offered comparison with other tropical fresh to gods and ancestors consist principally produce, and therefore stored yam of mashed yam. In parts of Igboland in represents stored wealth, which can Southeastern Nigeria, it is customary be sold all-year-round by farmers or for the parents of a bride to offer her marketers. Besides their economic yams for planting as a resource to assist importance, yams also play a significant her in raising a family. According to role in the socio-cultural lives of some Diop (1998), the ritual, ceremony and producing regions like the celebrated superstition often surrounding yam New Yam Festival in West Africa, cultivation and utilization in West Africa a practice that has also extended to is a strong indication of the antiquity overseas where there is a significant of use of this crop. In Nigeria, yam is population of the tribes that observe it considered to be a “man’s property” (Nweke et al, 2012). In some parts of and the traditional ceremonies that still 6 ROOT AND TUBER CROPS IN GHANA - AN OVERVIEW

accompany yam production indicate the just 50mm to more than 1000mm (FAO, high status given to the crop (Nweke 2008). The crop is able to resist many et al, 2012). In Ghana, celebration of plant diseases, drought and locust attack many new yam festivals in major yam and can be harvested at any convenient growing areas like Techiman, Atebubu, time, usually between 8 and 24months Yendi, etc. attest to the socio-cultural after planting depending on the variety. significance of the crop in Ghana. Cassava, therefore, serves as the last option among food crops in Cassava many African countries and provides Cassava is a major staple crop in a protection against unforeseen food Ghana and has almost become a shortages or famine (FAO, 2008; primary food security crop in Africa. Meridian Institute, 2009). However, the It contributes about 22% to Ghana’s choice of late harvesting could mean an agricultural GDP (ISSER, 2005). The opportunity cost of trading high quality total world utilization of cassava is and more starch content of the root for a projected to reach 275 million tonnes much lower quality and starch content. by 2020 (IFPRI, 2008). Cassava is the A major problem with caasava is its most widely produced root and tuber poor storability after harvest; once the crop, cultivated vastly in nearly all cassava root is unearthed, it has roughly the agro-ecological zones of Ghana. a two-day shelf life without treatment This is because the crop can survive on (ibid). poor quality soils within latitudes 30° The production of cassava in north and south of the equator with pH Ghana was estimated at 8.1 million ranging from 4 to 9. It also fares well in tonnes in the year 2000 and 16 .5 million temperatures ranging between 18°C and tonnes in 2014 (Figure 4). 25°C and areas with annual rainfall of ROOT AND TUBER CROPS IN GHANA - AN OVERVIEW 7

Figure 4: Cassava Production series for Ghana

Source: FAOSTAT, 2014.

The production of cassava in Ghana beneficiaries of these developments constitutes nearly 50% of all roots and (Haggblade and Theriault, 2012). tuber production, mainly by farmers Table 2 shows the production of who operate on a small-scale. At this cassava and the proportions that were scale, there is limited chemical and exported in the form of dried chips and mechanical input in the production, starch (quantities in tuber equivalent) harvesting, processing and other post- from 2005 to 2009. Only a small fraction harvest handling activities (MOFA/ of the total production were exported, SRID, 2012). Cassava is produced and the volumes kept declining from by more than 90% of Ghanaian 0.054% in 2005 to 0.0003% in 2009. farmers, either as a main crop or in The exports of cassava chips and starch combination with other crops. The kept declining because there was a increase in the production of cassava, decline in the demand for cassava chips together with the development of low- in Europe which could be ascribed to cost cassava processing technologies, the introduction of price interventions have contributed to the expansion for feed grains in the EU, promoting the of employment opportunities along utilisation of domestic grains (USDA the cassava value chain. Women, GAIN Report, 2012). Also, producers especially those engaged in marketing got better prices for selling cassava and processing, have been the main locally as against exporting chips and 8 ROOT AND TUBER CROPS IN GHANA - AN OVERVIEW

starch that were produced from it. In Export of cassava starch also dropped in 2008 and 2009, exports of dried cassava that year because the presidential special dropped significantly because of the initiative (PSI) processing facility was increased demand for domestic cassava. shut down (FAO, 2012).

Table 2: Production and Export of Cassava in Ghana, MT (2005-2010) Production/Export 2005 2006 2007 2008 2009 2010 Production (‘000MT) 9,567 9,638 10,217.9 11,351.1 12,230.6 13,504.1 A. Exported cassava chips 3,450 5,690 3,592 27 27 - B. Exported qty of starch 1,661 632.5 154 5.5 5.5 -

Exports (A+B) as a % of production 0.053% 0.066% 0.037% 0.0003% 0.0003% -

SOURCE: FAO STAT, 2012. In addition, the export companies of many Ghanaians with an estimated dealt directly with the numerous small annual per capita consumption of 151.4 scale farmers and chip processors by kg (FRI, 2012). It also accounts for up setting up chipping/ buying centers to 40% of daily food intake (kcal per in the producing districts to assemble capita per day), serving as a good source a required volume of chips to export. of carbohydrate. Its leaves are of high Processors complained of lack of nutritional value and can be eaten as a information flow on pricing and mode vegetable. In Ghana, cassava is mainly of payment of their products and used for household consumption; about therefore preferred to sell on the local 85 percent of the production is eaten as market. Of all the products in the cassva food (IITA, 2009) and its consumption value chain, Gari is the highly exported cuts across all ten administrative product and it has been growing annually regions of the country (World Bank, by 23.2% from 2001-2007. It has seen 2010). Due to the bulkiness and high a fair patronage in the EU and other perishable nature of fresh cassava, it is ECOWAS countries but there is still a usually traded in derived or processed firm competition from the ECOWAS forms which also serve as intermediate countries to Ghana’s exports of this products for human diet, animal feed, product (FAO, 2012).Locally, cassava bioethanol production and starch constitutes a major part of the diets markets. ROOT AND TUBER CROPS IN GHANA - AN OVERVIEW 9

Due to the increasing demand industry, cassava is used to produce by the urban populace for high quality glue, veneer adhesives and other binding products of processed cassava and materials. In addition to that, it is used the increased acknowledgement of its to produce eco-friendly and recyclable diverse industrial potential, there is plastics and textiles. Moreover, it is an increase in the commercial use of used in the pharmaceutical industry cassava (Jumah et al., 2006). There to derive glucose and dextrin from exist the demand for cassava in both cassava for syrups. The leaves, peels, food and non-food industries for high dried chips and pellets are also used as quality processed products of cassava at animal feed in the industry different end-user markets. An example (Dziedzoave et al., 2002). The peels are is the high demand for high quality also used as substrate in the production cassava flour (HQCF), where about of mushrooms. 1000 MT was produced in Based on the socio-economic as well as an increased production of significance of cassava, the government industrial grade cassava glue for the ply of Ghana launched a special program wood industry. called the “President’s Special Initiative A larger part of HQCF was (PSI) on Agribusiness” for starch supplied to the food industry and about production and processing for export in one half to the plywood manufacturing August 2001, as a means to transform sector (Kleih et al., 2013). In the food cassava into a major economic growth industry, cassava is processed mainly pole (Kasalu-Coffin et al., 2005). into cassava grits, commonly known as However, the success of the PSI on gari, cassava pellets (kokonte), cassava cassava was very minimal, due to flour, cassava dough (agbelima) and operational and technical challenges. starch. Some of the traditional meals Sweetpotato prepared from cassava are fufu, banku, Sweetpotato holds the position as one of akple, yaka yaka, agbeli kakro, akyeke, the main food security crops in Africa etc. Processing of cassava ranges from due to its resistance to drought, flexible simple boiling, drying and roasting of planting, harvest cycle and tolerance the roots to fermentation of the products of low-quality soils. Due to the crop’s as well as the production of alcohol for versatility and adaptability, it is ranked beverages and extraction of starches as a universal crop and seventh most (Appiah, 2017). important food crop next to wheat, , In the paperboard and plywood 10 ROOT AND TUBER CROPS IN GHANA - AN OVERVIEW

maize, potato, barley, and cassava; it is Central, Northern, Upper East, and an important source of carbohydrate, Volta Regions. Figure 5 provides land carotene and vital vitamins (CIP, 2000; area cultivated to sweetpotatoes and FAO, 2002). The consumption of the anual production volumes in Ghana crop is mainly in the fresh form by from 1996-2013. It can be seen from either frying, boiling or roasting. The the figure that much of the increase in vegetative parts (vines) are mostly fed production levels may be as a result of to livestock predominantly in areas such steady increases in the area cultivated. as central Kenya where zero It is also important to note that sweet management systems particularly in potato production levels over the period small scale dairying is well established. are seen to be generally fluctuating. They may also be utilized by young Notwithstanding this general trend, it calves as starter feed and partial milk is worth noting that from 2006-2013, replacer (Orodho et al., 1995).Notable there was a continuous increase in production areas and sweet potato production although a slight decline supply centers in Ghana are Eastern, occurred in 2010. Figure 5: Sweet Potato Production Trend in Ghana

160 Area cultivated(Ha) Production(000MT) 140

120

100

80

60

40

20 Area planted (Ha) and and planted ('000Mt) Area (Ha) Production

0 1994 1996 1998 2000 2002 2004 2006 2008 2010 2012 2014

Source: Generated from Author’s own computation obtained from FAO Stats, 2015. In Ghana, primary data on sweetpotato survey on regional basis to ascertain the production was very scarce until 2012 levels of sweet potato production in the when MoFA in collaboration with country. Table 3 provides information West Africa Agricultural Productivity on the area cultivated and the production Programme (WAAPP) conducted a levels of sweet potato by region. It may ROOT AND TUBER CROPS IN GHANA - AN OVERVIEW 11

be evident from the table that, bulk the chunk of production. However, the (54.3%) of sweet potato produced in the produced the bulk of country comes from the Northern sector sweet potatoes in the southern part of with the Upper East region contributing Ghana. Table 3: Sweet Potato Production in Ghana (2012) Region Area (Ha) % Contribution Production (Mt) % Contribution Central 371 3.9 6,490 4.9 Volta 880 9.1 15,340 11.6 Eastern 1,030 10.7 34,910 26.4 Gt. Accra 38 0.4 640 0.5 Ashanti 37 0.4 620 0.5 Brong Ahafo 145 1.5 2,390 1.8 Northern 414 4.3 6,070 4.6 Upper East 5,550 57.7 46,000 34.9 Upper West 1,157 12 19,530 14.8 Total 9622 100 131990 100

Source: MoFA Field Survey, 2012. The sweet potato value chain in Ghana Cocoyam comprises many actors interlinked by Cocoyam is an herbaceous plant different governance structures which which belongs to the family Araceae expose them to different risks and and is usually cultivated for its edible constraints. Like most agricultural roots, although other parts of the plant, enterprises, sweetpotato production especially its leaves, are used as human and marketing are subject to many risks food. Cocoyam is the universal name emanating from weather, technical and for corm and tuber plants in the Araceae institutional constraints. Addressing or Aroids family. It belongs to either constraints in sweet potato production the genus Colocasia or Xanthosoma as well as in the physical, facilitating and are generally comprised of a large and exchange functions in the spherical corm (swollen underground marketing of the commodity promise storage stem), from which a few large huge improvements in poverty and food leaves emerge (AGRO-HUB, 2013). security status of chain actors (Wie, Even though cocoyam 2016). encompasses different genera 12 ROOT AND TUBER CROPS IN GHANA - AN OVERVIEW

such as Alocasia, Crytospema and cocoyam voluntarily springs up anytime Amorphophallus, the two most secondary forests are cleared because extensively cultivated species in Sub- of the presence of old pieces of corms Saharan Africa are Colocasia esculenta and cormels lying dormant in soils of and Xanthosoma sagittifolium (Onyeka, old and abandoned farms (Acheampong 2014). The leaf blades are large and et al. 2015). Cocoyam cultivation heart-shaped and can reach 50 cm is primarily by cutlass and hoe and (15.8 in) in length. The corm produces cultivars are either sourced from own lateral buds which give rise to tubers farms, gifted to farmers who need it or cormels and suckers or stolons. or purchased from fellow farmers. A Cocoyam commonly reaches in excess major source of planting material for of 1 m (3.3 ft) in height and although planting is from dormant corm setts that they are perennials, they are often sprout voluntarily after a piece of land is grown as annuals, harvested after one cleared for farming (Sagoe, 2006). season (PlantVillage, 2014). Cocoyam ranks fifth in importance In Ghana, there are two common in terms of production of staple crops in varieties of cocoyam; the white and red Ghana. Characteristically, it is cropped or mauve types. The root crop usually for its roots (corms) and leaves at takes between 12 to 18 months before subsistence level by farmers. Therefore, harvesting. Wright (1930) indicates the only the production surplus is supplied root crop was first introduced to Ghana to markets in the urban centres for by missionaries from the West Indies. cash. Onyeka, (2014) noted that during Cocoyam was first planted at Akropong critical periods of crop failure, outbreak Akuapem in the Eastern Region of of devastating pests and diseases to Ghana. The crop gradually spread out main crops, drought, famine, conflict or to other areas within the forest belt. other natural disasters, cocoyam is the Cocoyam was easily established within staple food that farmers and the rural the forest zones of the country mainly folks depend on to mitigate hunger. because of the predominance of cocoa Consequently, cocoyam is the crop that production along the forest belt. many dwellers in the rapidly growing Cocoyam complemented cocoa urban centres consume especially in off- by providing an ideal shade for cocoa season times of plantains (Acheampong seedlings. During the early years of et al. 2014). establishment, cocoyam was cultivated According to Sam and Dapaah after virgin forests were cleared. Now, (2009), cocoyam is an alternative ROOT AND TUBER CROPS IN GHANA - AN OVERVIEW 13

source of carbohydrates for most of the protein. It also contains thiamine, people in West Africa and the Pacific. riboflavin, and niacin as well as Cocoyam corms, cormels and leaves are significant amounts of dietary fiber. eaten after roasting, boiling or baking. Cocoyam also contains higher amounts Meals, sauces and baking flours can of essential minerals like Mg, Ca, K and P also be prepared out of it. It can also than yam, cassava and plantain (Eleazu, be pounded, fried, milled or converted 2013 and Niba, 2003). Cocoyam leaves into other semi-processed end products are also a good source of vitamins A and for stabilizing (Owusu-Darko et al. C and contain about 20 percent protein 2014). Cocoyam is considered the on dry weight basis which is more than most nutritious compared to other root the amount of protein contained in the and tuber crops like yam and cassava. corms. Cocoyam leaves are highly According to Onyeka, (2014) cocoyam recommended for diabetic patients, has nutritional values comparable to the aged, children with allergies and potato. for other persons with gastro-intestinal A lot of nutrients are derived disorders (Plucknett, 1970). Table 4 from the corms, cormels and leaves. provides a summary of the nutritional Owusu-Darko et al. (2014) noted that contents of cocoyam per 100g of edible cocoyam contains 20 to 28 percent portion. starch (carbohydrates) and 1.12 percent 14 ROOT AND TUBER CROPS IN GHANA - AN OVERVIEW

Table 4: Nutritional content of cocoyam per 100g edible portion

Constituent Tannia (Xanthosoma saggittifolium) Major Nutrients Corms Leaves Shoots Calories 133 34 24 Protein (g) 2.0 2.5 0.5 Fat (g) 0.3 1.6 0.2 Carbohydrates (g) 31 5 6 Fibre (g) 1.0 2.1 0.9 Calcium (mg) 20 95 49 Phosphorus (mg) 47 388 25 Iron (mg) 1.0 2.0 0.9 Vitamins -carotene equiv (g) trace 3300 - Thiamine (mg) 0.10 - - Riboflavin (mg) 0.03 - - Niacin (mg) 0.5 - -

Ascorbic acid (mg) 10 37 82

Source: Opara (2003) The starch from cocoyam is readily such as palaver sauce and agushi stew digestible, hence it is used to prepare can be prepared with it. Cocoyam is used baby food (by cutting corms into pieces, as a ready alternative to plantain and boiling and mashing). Owusu-Darko yam in making ‘fufu’ or ‘ampesi’ during et al. (2014) noted that the smaller the off-seasons of yam and plantain. It is starch granules of cocoyam have been also common in Ghana to find cocoyam associated with better digestibility over chips which are deep-fried slices of the other starchy crops. The young fresh corms about 1 mm thick often prepared leaves locally known as ‘kontomire’ and sold as snack (Owusu-Darko et al., are used as vegetables after boiling in 2014). order to remove the acrid flavour (which Cocoyam has other uses aside the causes irritation in the throat or mouth commonly known traditional culinary linings upon ingestion). Local sauces uses. The flour can be used to bake ROOT AND TUBER CROPS IN GHANA - AN OVERVIEW 15

bread and biscuits, prepare soups, producer of cocoyam, producing 3.9 beverages, and puddings. Cocoyam million tonnes (40.5 percent of total starch can be modified into becoming production) in 2013. China, Cameroon an alternative to the other commonly and Ghana follow in order of importance used industrial starches (Lawal, 2004). producing 1.8 million (19.2 percent Subhadhirasakul et al. (2001) reported of total production), 1.6 million (16.1 that cocoyam starch can be used to percent of total production) and 1.3 effectively replace maize as a binding million tonnes (13.1 percent of total agent in the manufacture of tablet drugs. production) of cocoyam respectively Sub-Saharan Africa (SSA), is (FAOSTAT, 2014). In 2014, Africa by far the world’s major producer of accounted for 52 percent of the total cocoyam according to the statistics from (cocoyam) production in terms the Food and Agriculture Organization of Gross Production Value (Figure (FAOSTAT, 2014). Onyeka (2014) 6). Africa’s total gross product value indicated that SSA alone accounted for (GPV) has decreased by US$ 412 74 percent of total cocoyam production million while Asia’s has appreciated in the world between 2008 and 2013. by US$ 107 million between 2008 and In 1999, the FAO Database reports 2012. Generally, cocoyam production showed that about 6.6 million tonnes of worldwide has slightly decreased by cocoyam were produced worldwide on 13.4 percent between 2008 and 2014 a total land area of 1.07 million hectares. (FAOSTAT, 2014). Nigeria is the world’s largest

Figure 6: World cocoyam production – Gross Production Value – constant 2004-2006 million US$

Source: FAOSTAT, (2014) 16 ROOT AND TUBER CROPS IN GHANA - AN OVERVIEW

production has subsequently decreased. In 2013, Ghana contributed about 13 In Africa, statistics show that Cameroon percent of the world’s total cocoyam and Nigeria are experiencing gradual production (FAOSTAT, 2014). increase in production as at 2012 even Production in Ghana appeared to though cocoyam production in Nigeria have peaked between 2007 and 2008, severely dropped between 2009 and but that was not sustained for long 2011. Figure 7 depicts the trend of because production started declining cocoyam production for the three till 2013. Onyeka (2014) posits that most important producing countries in this period of sharp decrease coincided Africa. The figure shows that Ghana has with the outbreak of taro leaf blight in been experiencing consistent annual the region. Annual production statistics production fall since 2003 (Figure 8). from MoFA-SRID (2013) reveal that Ghana is currently the fourth national output of cocoyam declined by most important cocoyam producer in about 25.2 percent between 2000 and the world and third in Africa. Available 2013. National production information statistics show that by 1996, Ghana on cocoyam leaves is hardly available was the world’s leading producer of however, since both the corm and leaves cocoyam contributing 1.6 million tonnes are composite products of cocoyam, per annum representing 36.4 percent production decline will also be reflected of world’s total production (Onyeka, in the output and availability of cocoyam 2014). Percentage contribution to world leaves.

Figure 7: Trend of cocoyam production for top three producers in Africa ROOT AND TUBER CROPS IN GHANA - AN OVERVIEW 17

Source: FAOSTAT (2014). The root crop is most suitable in the Ahafo and Western forest areas of Ghana hence the bulk of are noted for the production of cocoyam cocoyam is produced along the forest even though other regions like Volta and belt of Ghana. Acheampong et al., Central Regions produce the root crop (2014) stated that cocoyam production on purely subsistence scale (Figure 9). occurs in the southern parts of Ghana The major cocoyam producing regions where there are lots of vegetation cover (Ashanti and Eastern) have experienced and relatively well distributed amounts the hardest decrease in production over of rainfall. Ashanti, Eastern, Brong the past decade. Figure 8: Trend of cocoyam production and area harvested from 2000-2013

Sources: (FAOSTAT, 2014; MoFA – SRID, 2013) 18 ROOT AND TUBER CROPS IN GHANA - AN OVERVIEW

Figure 9: Regional production trend of cocoyam (2000-2011)

Source: (MoFA-SRID, 2013; Acheampong et al. 2014) Cocoyam generates significantvalue per tonne which favourably amounts of foreign exchange for compares with that of yam. Data the country through exports. The from Ghana Export Promotion export market for cocoyam presents Council (GEPC) shows that between itself with a vast potential due to the 2000 and 2013, Ghana exported demand for both corms and leaves 2176.88 metric tonnes of cocoyam largely by West Africans living in worth US$1,170,641.7 (Table 5). the diaspora and the good export ROOT AND TUBER CROPS IN GHANA - AN OVERVIEW 19

Table 5: Export volumes and values for cocoyam in Ghana

Quantity Value (US$) Year Total export value (US$) (metric tonnes) (US$/mt) 2000 117 464.9 54393.3 2001 172 343.0 58996 2002 224 347.3 77795.2 2003 228 364.0 82992 2004 64 562.5 36000 2005 189 507.9 95993.1 2006 243.73 634.3 154597.9 2007 234.04 485.0 113509.4 2008 272.23 776.0 211250.5 2009 241.83 678.9 164178.4 2010 96.84 603.6 58452.62 2011 61.49 832.2 51171.98 2012 32.72 345.7 11311.3

Source: Acheampong et al. (2014); GEPC (2013)

Conclusion is required to unleash the full potential Root and tuber crops will continue to of root and tubers to reduce poverty, play significant roles in the farming malnutrition and hunger in Ghana and systems and food consumption patterns Africa as a whole. in Ghana. However, many production, marketing, processing, financial and logistical constraints have stifled the growth of the root and tuber industry in the country. Introduction of improved technologies along the various nodes of the root and tuber value chains would spur growth in the sector to engender job creation for improved livelihoods of key actors in these value chains. Continuous innovative research focusing on specific root and tuber crops 20 ROOT AND TUBER CROPS IN GHANA - AN OVERVIEW

REFERENCES

Acheampong, P. P., Osei-Adu, J., Amengo, E., Sagoe, R. (2014). Cocoyam value chain and benchmark study in Ghana. A report submitted to West African Agricultural Productivity Project (WAAPP). Project Information Document. pp 7-11 AGRO-HUB (2013). Cocoyam. Accessed from http://agro-hub.com/portfolio-view/ cocoyam/#.VTuM3pPSf_g on 25/04/2015 Aidoo Robert (2009). An Analysis of yam consumption pattern in Ghanaian urban communities, PhD Dissertation submitted to Kwame Nkrumah University of Science and Technology (KNUST), Kumasi-Ghana. Appiah, B. Gifty (2017). Efficiency, Competitiveness and Technology Gaps in the Cassava Value Chain in Ghana, PhD Dissertation submitted to Kwame Nkrumah University of Science and Technology (KNUST), Kumasi-Ghana. Dziedzoave, N. T., Graffham, A. J., Mensah, B. A. and Gyato, M. (2002) ‘Use of Cassava Flour in Paperboard Adhesives’. In: Proceedings of the 12th Symposium of the International Society for Tropical Root Crops (ISTRC), Tsukuba, Japan: http:// www.tiu.ac.jp/~bduell/ISTRC/Symposiums/Japan.00.html Eleazu, C. O., Iroaganachi M., and Eleazu, K. C., Ameliorative Potentials of Cocoyam (Colocasia esculenta L.) and Unripe Plantain (Musa paradisiaca L.) on the Relative Tissue Weights of Streptozotocin-Induced Diabetic Rats. Journal of Diabetes Research. Vol. 2013. Article ID 160964. doi:10.1155/2013/160964 FAOSTAT (2014). Production Statistics Ghana, Cameroon, Nigeria – Taro (cocoyam). Sourced from http://knoema.com/FAOPRDSC2015Feb/production-statistics- crops-crops-processed-february-2015 on 12/09/2015. FAOSTATS (2015). FAO Statistics. Food and Agriculture Organization, Rome, Italy [http:www.apps.fao.org].Orodho et al., 1995) FAO (2002). FAO Statistics.Food and Agriculture Organization, Rome, Italy [http:www. apps.fao.org]. FAO (Food and Agricultural Organisation) (2012). Promoting CARICOM/CARIFORUM Food Security (Phase II) (GTFS/RLA/141/ITA): Evaluation Report. FAO, Rome, Italy. FAO (2008). Value Chain Analysis of Cassava Subsector in Zambia. Part II: Value Chains Analysis Final Report .GTFS/RAF/364/ITA ISSER (Institute of Statistical, Social and Economic Research) (2005): The state of Ghanaian Economy in 2004, ROOT AND TUBER CROPS IN GHANA - AN OVERVIEW 21

University of Ghana, Legon-Accra FAOSTAT (2015). Statistics of the Food and Agricultural Organization: Retrieved on 10th February, 2015. http://faostat.fao.org/site/567/DesktopDefault.aspx FRI (Food and Research Institute) (2012) ‘Gratitude Draft Report on Cassava Value Chain’. GSS (Ghana Statistical Service) (2014): Statistics for Development and Progress: Final Gross Domestic Product for 2012 and Revised GDP for 2013. National Accounts Statistics (GDP 2014): available at www.statsghana.gov.gh Haggblade, S. and Theriault V. (2012) ‘Improving the Inclusiveness of Agricultural Value Chains in West Africa: The Role of Market Segmentation and Emerging Sub-Channels’. http://www.aec.msu.edu/fs2/IFAD-WA/index.htm IITA (International Institute of Tropical Agriculture) (2009): The Root and Tuber System, Medium Term Plan, 2009-2011. www.iita.org Kasalu-Coffin, E., Bedingar, T., Dosso, H. and Diop, E. (2005) ‘Ghana Export Marketing and Quality Awareness Project’. Appraisal Report Kleih, U., Phillips, D., Wordey, M. T., Komlaga, G. (2013) ‘Cassava Market and Value Chain Analysis, Ghana Case Study’. Final Report January 2013. Lawal, O. S. (2004). Composition, physicochemical properties and retrogradation characteristics of native, oxidised and aceteylated and acid-thinned new cocoyam starch. Food Chemistry. 87: 205-218. Meridian Institute (2009) ‘Innovations for Agricultural Value Chains in Africa: Applying Science and Technology to Enhance Cassava, Dairy, and Maize Value Chains’. Cassava Value Chain Overview MOFA/SRID (Ministry of Food and Agriculture/ Statistics, Research and Information Directorate) (2012) ‘Various Statistics compiled by the Statistics, Research, and Information Directorate (SRID) of the Ministry of Food and Agriculture (MOFA)’. Accra, Ghana. MoFA-SRID (2013). Agriculture in Ghana: Facts and Figures 2012. Statistics, Research and Information Directorate. Ministry of Food and Agriculture. Accra, Ghana. MoFA (2013). Crops Subsector (). Major Crops Produced, Cropped Areas and Performance. Assessed from www.MoFA.gov.gh/site/?page_id=972 on 12/09/2013. MOFA/SRID (Ministry of Food and Agriculture/ Statistics, Research and Information Directorate) (2012) ‘Various Statistics compiled by the Statistics, Research, and Information Directorate (SRID) of the Ministry of Food and Agriculture (MOFA), Accra, Ghana. MOFA (Ministry of Food and Agriculture) (2011) ‘Agriculture in Ghana, Facts and Figures’. Statistics, Research and Information Directorate (SRID), Accra, Ghana. 22 ROOT AND TUBER CROPS IN GHANA - AN OVERVIEW

Niba, L. L. (2003). Processing effects on susceptibility of starch to digestion in some dietary starch sources. International Journal of Food Sciences and Nutrition. 54 (1): 97–109. Nweke F, Okoye B.C and Aidoo R (2013). Yam Consumption Patterns in West Africa; Technical report for Bill and Millender Gates Foundation. Onyeka, J. (2014). Status of Cocoyam (Colocasia esculenta and Xanthosoma spp) in West and Central Africa: Production, household importance and the threat from Leaf Blight. CGIAR Research Program on Roots, Tubers and Bananas (RTB). Opara, L. U. (2003). Edible Aroids: Post-harvest operation. In Post-Harvest Compendium. FAO. Rome. Owusu-Darko, P. G., Paterson, A., & Omenyo, E. L. (2014). Cocoyam (corms and cormels): An underexploited food and feed resource. Journal of Agricultural Chemistry and Environment. 3(1): 22-29. PlantVillage (2014). Cocoyam. https://www.plantvillage.com/en/topics/cocoyam/infos/ diseases_and_pests_description_uses_propagation on 25/04/2015 Plucknett, D. L. (1970). Status and future of the major edible aroid Colocosia, Xanthosoma, Alocasia, Cyrstosperma and Amorphophallus. In Tropical Root Crops Tomorrow: Proceedings of the 2nd International Symposium on Tropical Root Crops, Hawaii, pp 127-35. Sagoe R. (2006). Climate change and root crop production in Ghana. , Kumasi. Prepared for Environmental Protection Agency (EPA). Sam, J. & Dapaah, H. (2009). Baseline survey report-West African Agricultural Productivity Programme (WAAPP). Ghana. Subhadhirasakul, S., Yuenyoungsawwad, S., Ketjinda, W., Phadoongsombut, N. & Faroong-Sarng, D. (2001) Study on tablet binding and disintegration properties of alternate starches prepared from taro and sweet potato tubers. Drug Development and Industrial Pharmacy. 27: 81-87. Wie, 2015. Assessment of risks and constraints of actors along the sweet potato value chain in Ghana, MPhil Dissertation, KNUST. Wright, J. (1930).Cocoyam varieties in the Gold Coast. Gold Coast Department of Agriculture (1930): Bulletin No. 23: 198-201. 23

THEME I:

MARKETING, VALUE CHAINS, ECONOMICS AND EXTENSION ISSUES IN THE GHANAIAN ROOT AND TUBER INDUSTRY 24

STRUCTURE, CONDUCT AND PERFORMANCE OF THE GARI MARKET IN MAMPONG AND TECHIMAN MUNICIPALITIES IN GHANA

Aidoo Robert, James O. Mensah, Appiah Barnie Isaac, Aboagye Ernest Tabbih, Assamoah-Cobbiah George, and Yirenkyi Ahmed Kojo Department of Agricultural Economics, Agribusiness & Extension, Kwame Nkrumah University of Science & Technology (KNUST), Kumasi- Ghana

ABSTRACT of the conduct of actors in the market. This study sought to assess the The study revealed that Gari wholesaling structure, conduct and performance of and retailing are almost perfectly the Gari market in the Mampong and competitive whereas the processing Techiman municipalities. A purposive sector is weak oligopolistic in nature in sampling technique was used to select both municipalities. In terms of conduct, the communities in both municipalities. players in the gari market relied heavily Simple random sampling technique was on the forces of demand and supply to used to select one hundred (100) actors set prices. The Gari business was found in the Gari market in each municipality to be profitable in both municipalities including 40 processors, 40 retailers as it generated positive gross and net and 20 wholesalers and structured marketing margins at all nodes of the questionnaires were employed to elicit market chain. However, net margins primary data for analysis. Descriptive were not equitably distributed among statistics, frequency tables and the key market participants, a situation percentages were used to summarize which could threaten the sustainability the socio-demographic characteristics of the chain, especially in the Mampong of respondents. Gross margins, Net municipality. The study revealed that marketing margins, Concentration ratio, major constraints faced by processors and Herfindahl-Hirschman Index (HHI) were limited access to credit, price were used to examine the structure and performance of the market. Simple fluctuations and low efficiency of narrations were also used in the analysis processing equipment. Among traders, STRUCTURE, CONDUCT AND PERFORMANCE OF THE GARI MARKET 25

the most pressing constraints were Gari processing and marketing limited access to credit, inconsistent are important economic activities that supply of Gari and high transportation serve as sources of livelihoods for many cost. To ensure consistency and product . A well-functioning traceability, there is the need for Gari market will guarantee regular product differentiation and innovation income and food security for not only through packaging, labelling and value the actors in the chain, but members of addition for niche markets. Formidable their entire households. Income from trader associations are also needed in the business is used to supplement the industry to facilitate linkages and household income to cater for children’s strategic alliances with institutional education and other family needs. A buyers and other stakeholders in the well-performing Gari market will also larger enabling business environment. drive the production of cassava (the main raw material) further and therefore BACKGROUND help secure the livelihoods of farmers in An efficient marketing system is rural communities. essential for developing and also Although Gari is very popular maximizing returns from agricultural and essential among Ghanaians and production. In this regard Abott (1981) some people in the West African has pointed out that an efficient market sub-region, there has not been much acts as bridge between the producer improvement in its marketing system and consumer. It is through the market in Ghana. Issues of poor packaging and that production patterns are changed labelling, less value addition, limited according to the requirements of differentiation, inefficient production customers. Gari, a granular flour of methods which affect the final quality varying texture, is a widely patronized of the product are usually raised by Ghanaian food item that has over the consumers (Mylene and Kirsten, 2001). years served as a good companion to This is likely to affect the performance the citizenry especially students at all of the product on the market in an era levels from the primary schools to the where consumers are very conscious universities particularly those in the and are increasingly diverting to malls, boarding and hostel facilities. This specialty stores and restaurants instead is due to its relative long shelf life of the traditional supermarkets and and affordability compared to other retail shops for quality, variety and traditionally made consumables. value for money. As a result, packaging 26 STRUCTURE, CONDUCT AND PERFORMANCE OF THE GARI MARKET

of products seems to play a major role Region). Population was all actors in marketing now. Consumers who involved in Gari processing and are now conscious of product safety, marketing in both municipalities. Sample traceability and nutritional value look size was 200, with 100 respondents for proper packaging with product sampled from each district and made up labels; and this is hardly found in the of 40 processors, 20 wholesalers and 40 Gari market in Ghana. Key players in retailers. In the Techiman municipality the value chain are not market-oriented the study focused on Aworowa, and this has led to low productivity and Tuobodom, Akrofuom and Krobo profitability. communities. Kyiremfaso, Mampong, There is little or no coordination Krobo and Woraso were the selected among trading partners and thus most communities visited in the Mampong processors operate in spot markets municipality. These communities were which make them vulnerable to purposively selected because they are powerful market women in a market well known for Gari processing in both characterized by imperfect information districts. From each community, ten flow. Increased gari production, processors of gari were selected through however needs to be accompanied by simple random sampling. Wholesalers efficient marketing system that provides and Retailers were also selected from place, time, form and possession utility the main markets in the districts by to the customer. simple random samling technique. This research, therefore, sought Primary data was collected through to examine the structure, conduct and personal interviews with the use of performance of the gari market to structured questionnaires. Additional provide useful information for future information necessary to supplement policy and strategy formulation towards the primary data was derived from the efficient functioning of the gari market internet, journals and Ministry of Food in Ghana. and Agriculture (MOFA).

METHODOLOGY OF THE DATA ANALYSIS STUDY Characteristics of respondents were Study areas/Sampling/Data Collection summarized and described using Study areas were Mampong descriptive statistics and with the Municipality (Ashanti Region) and help of Statistical Package for Social Techiman Municipality (Brong-Ahafo Scientists (SPSS). The descriptive STRUCTURE, CONDUCT AND PERFORMANCE OF THE GARI MARKET 27

analysis made use of frequency tables, percentages and arithmetic mean. The Structure-Conduct-Performance (SCP) framework was used in assessing the Where; Gari market structure, conduct and S represents market share of the ith firm performance in Ghana. This study i N represents the total number of firms adopted Concentration Ratio (CR) and for which the index was calculated. Herfindahl – Hirschman Index (HHI) Potential barriers to entry were in analyzing the degree of traders’ investigated based on initial capital, concentration in the market place in technology involved, legal and performing the exchange function. The institutional requirements. Product concentration ratio was estimated using differentiation was investigated based the formula below. on presence or otherwise of product packaging, labelling and customer relation. The market conduct was examined based on information such Where CR= Concentration Ratio, as existence of trader associations, th Si represents market share of i firm availability of price and product n is the number of largest firms in the supply information (and means of market. communication); and pricing strategies Herfindahl-Hirschman Index (HHI) adopted. Narrations were used to was calculated by squaring the market present results relating to these market share of each firm competing in the conduct issues. market, and then summing the resulting Gross margin and Net margin were numbers. used in measuring maket performance. They were calculated mathematically by using the following equations:

Where: TGMi= total gross margin i=actor in the chain

Where, TNM = Net margin i= actor in the chain 28 STRUCTURE, CONDUCT AND PERFORMANCE OF THE GARI MARKET

Gross and net margins were calculated the general situation in Ghana where based on the number of bags (120kg per trading activities especially in the food bag) of Gari bought and sold monthly sector are predominantly controlled by by wholesalers and retailers in the gari women. business. Marketing costs included Among the Processors the transportation cost, labour cost (loading dominant educational level was basic and off-loading), selling expenses, ducation representing 64% followed storage cost, and value of losses, etc. by no formal education (30%) and Simple proportion was used to examine secondary education (5%). Majority of the distribution of costs and margins the wholesalers and retailers had basic among key actors in the gari market. education, represented by 53% and 55% respectively. The overall educational FINDINGS status of respondents was very low. Demographic Characteristics of The relatively low educational status of respondents respondents is not surprising given the Table 1 presents the distribution fact that most agro-industrial processing of respondents by sex, educational activities do not demand higher level of level and marital status. It may be academic qualifications. seen that only 6% of processors were Table 1 also shows that most of males with the remaining 94% being the key players in the gari market were females. Gari trading activities were married; 91% for processors and 90% completely dominated by women since for traders. This means that actors in 100% of traders in both study areas the gari business could rely on family were females. This is a reflection of labour to perform certain activities. STRUCTURE, CONDUCT AND PERFORMANCE OF THE GARI MARKET 29

TABLE 1 Demographic characteristics of Respondents

PROCESSORS WHOLESALERS GENDER RETAILERS (N=80) (N=80) (N=40)

Variable Frequency % Frequency % Frequency %

SEX

Male 5 6.25 0 0 0 0

Female 75 93.75 40 100 80 100

EDUCATIONAL BACKGROUND

No formal 24 30 16 40 33 41.25 education

Basic 51 63.75 21 52.5 44 55

Secondary 4 5 3 7.5 3 3.75

Tertiary 1 1.25 0 0 0 0

MARITAL STATUS

Married 73 91.25 36 90 72 90

Single 3 3.75 1 2.5 1 1.25

Widowed 2 2.50 3 7.5 7 8.75

Divorced 2 2.50 0 0 0 0

Source: Field survey (2016) Table 2 provides the descriptive municipality with an average processor statistics of respondents. The table being 43years and trader being 41years shows that majority of the key players old. This suggests that most of the were in their forties; average age of respondents were fully active and in processor was 42 years and 40 years for their prime working age. The number traders in Mampong municipality. The of years in business in Mampong for same condition existed in Techiman processors and traders averaged 10.48 30 STRUCTURE, CONDUCT AND PERFORMANCE OF THE GARI MARKET

and 8.85 years respectively and that of higher quantities of gari than those in Techiman were 11.12 and 11.87 years Mampong since the mean quantities respectively. This indicates that actors produced and handled by Processors in Techiman were more experienced and Traders in Techiman were 6600 kg and skilled in Gari processing than and 9840 kg respectively. Processors their counterparts in Mampong. It is and Traders in Mampong municipality evident from Table 2 that those actors produced an average of 1200 kg and in Techiman produced and handled 3530 kg of gari per month respectively. TABLE 2: Descriptive Statistics of Respondent characteristics

Mampong Techiman Variable Processors Traders Processors Traders Mean Std. Dev. Mean Std. Dev. Mean Std. Dev. Mean Std. Dev. Age (yrs.) 41.90 7.97 40.20 7.65 42.53 8.91 41.27 9.09 Experience (yrs.) 10.48 6.83 8.85 5.56 11.12 8.03 11.87 7.97 Household size 6.65 2.99 6.53 2.15 6.03 2.60 6.27 2.16 Years of formal 5.55 4.10 6.05 3.77 4.73 3.44 5.82 4.10 education Quantity of gari handled monthly 1200 5.46 3530 9.36 6600 21.55 9840 50.75 in Kg Source: Field survey (2016)

Market structure 12, 24, 24 and 24 bags (120kg per bag) From Table 3, the market share ratio of gari per month averagely.The largest showed 35.82% for processors, 49.77% eight wholesalers used in determining for wholesalers and 37.37% for retailers the market ratio produced 24, 34, 32, 24, in the Mampong municipality and the 28, 24, 25 and 30 bags (120kg per bag) Herfindahl-Hirschman Index (HHI) was of gari per month averagely. The largest estimated at 0.03 for processors, 0.05 eight retailers used in determining the for wholesalers and 0.03 for retailers market ratio produced 12, 12, 15, 16, in the same municipality. The largest 16, 11, 14 and 12 bags (120kg per bag) eight processors used in determining of gari per month averagely. All the the market ratio produced 16, 12, 20, 12, respondents share of gari produced STRUCTURE, CONDUCT AND PERFORMANCE OF THE GARI MARKET 31

per month were used in estimating the the Techiman municipality. All the Herfindahl-Hirschman Index (HHI) for respondents share of gari handled per each actor. month were used in estimating the In the Techiman municipality the Herfindahl-Hirschman Index (HHI) concentration ratio was therefore found for each actor. The market structure of to be 29.51% for processors, 58.9% for Gari is almost perfectly competitive wholesalers and 41.2% for retailers. for both wholesalers and retailers. The largest eight processors used in However, processing structure is weak determining the market ratio produced oligopolistic in nature. The Gari market 72, 72, 72, 72, 72, 72, 108 and 108 was characterized by many buyers and bags (120kg per bag) of gari per month sellers. The condition of the market is averagely. The largest eight wholesalers free entry and exit with the exception used in determining the market ratio of Techiman market where there was a handled 70, 145, 80, 58, 58, 110, 80 barrier of consulting the market queen and 210 bags (120kg per bag) of gari if a shed was needed for operations. per month averagely. The largest eight There is perfect knowledge, little or no retailers used in determining the market advertisement, product homogeneity, ratio produced 16, 16, 24, 24, 40, 30, no legal and institutional barriers and 35 and 35 bags (120kg per bag) of gari low level of technology employed in per month averagely .The Herfindahl- their operations for both municipalities Hirschman Index (HHI) was calculated which is consistent with the findings of to be 0.03 for processors, 0.07 for Olagunju et al. (2012). wholesalers and 0.03 for retailers in 32 STRUCTURE, CONDUCT AND PERFORMANCE OF THE GARI MARKET

TABLE 3: Market Concentration Ratio for Gari markets in Techiman and Mampong

MARKET HERFINDAHL- MONTHLY SHARE RATIO HIRSCHMAN INDEX

NUMBER OF (CR8) (HHI) PLAYER BAGS(120kg/ bag)

MAMPONG PROCESSORS 402 35.82 0.03

WHOLESALERS 444 49.77 0.05

RETAILERS 289 37.37 0.05 TECHIMAN PROCESSORS 2196 29.51 0.03

WHOLESALERS 1378 58.9 0.07

RETAILERS 534 41.2 0.03

Source: Field Survey (2016) Market Conduct All the respondents confirmed that during the bumper season from August to prices are set by factors such as demand January, cassava roots are in abundance and supply and cost of acquisition plus increasing the output of processors. margin which confirms the finding This leads to supply exceeding demand. of (Afolabi, 2009). Demand mostly Prices therefore decrease ranging exceeds supply in the lean season and from GH₵180 to Gh₵220 per 120kg supply exceeds demand in the bumper bag of gari. Gari traders association season. The lean season spans from exists only in the Techiman market February to July. During this time and does not exclude anybody from harvesting of cassava is very tedious selling in the market. The association due to lack of rains. Cassava roots does not interfere in the trading but for become scarce hence low output from welfare purposes. There is low level processors. Demand therefore exceeds of product differentiation in the Gari supply resulting in price increase market except for their fineness and ranging from GH₵250 to GH₵330 per color in the market. The colour of gari 120kg bag of Gari. On the contrary, produced in Techiman is usually yellow STRUCTURE, CONDUCT AND PERFORMANCE OF THE GARI MARKET 33

mostly preferred by senior high schools, were GH¢800 and 34.78% and a Net prisons service, food vendors, and final Margin estimated at GH¢28.02 and consumers and other customers. Gari in 1.22% respectively in the Mampong Mampong is usually white in colour and municipality. A processor sold an mostly preferred by senior high schools, average of 10bags (120kg per bag) of prison service, final consumers, food Gari every month. This indicates that vendors and other customers. for every GH¢1 invested in processing Most of the respondents activity a gross margin of 34.78% (92.5%) confirmed there is readily and a net margin of 1.22% accrued available information on price in their to processors. The cost price item for market of operation. The respondents processors consists mainly of fresh confirmed that information about raw cassava tubers costing GH¢1500 in material is available through mobile Mampong. A processor handled an communication with farmers and visits average of 10 tricycles (333kg of to farms. cassava roots per tricycle) per month at an average price of GH¢ 150 in Market Performance Mampong municipality. From Table 4 the profitability analysis The major cost items making of the 200 respondents in the study area up the processing costs were water, for the year 2016, indicated that Gari firewood, peeling, grating, milling, processing was generally profitable, roasting and packaging totaling recording both positive gross margins Gh¢771.98 in Mampong. This was and net profits in both municipalities. incurred for processing 3330kg of From Table 4 the average Gross cassava roots per month. Grating and Margin accrued to a processor milling activities were done together in per month in value and percentage a single machine. 34 STRUCTURE, CONDUCT AND PERFORMANCE OF THE GARI MARKET

TABLE 4 Average monthly costs and returns of processors in Mampong and Techiman

ITEM MAMPONG TECHIMAN Output 10 bags 55 bags Selling price per Unit Gh¢230 Gh¢250 A. Gross revenue Gh¢2300 Gh¢13750 Output 10 tricycles 6 trucks Cost price per Unit Gh¢150 Gh¢1400 B. Variable Cost/Cost of produce Gh¢1500 Gh¢8540 C. Gross Margin (A-B) Gh¢800 Gh¢5210 Gross margin as % of gross Revenue ( 34.78% 37.89% ) Amount Amount Processing costs Gh¢ Gh¢ Water 9 - 30 (25lt gallon)*0.30p Firewood 340.5 823.5 Peeling 136.2 183 Grating, labor and pressing - 152.5 Milling 138.72 366 Roasting 113.52 658.8 Packaging 34.04 164 D. Total processing costs 771.98 2348.5 E. Net Margin(C-D) 28.02 2861.5 Net margin as % of Gross revenue 1.22% 20.81%

Source: field survey (2016) Also, the average Gross Margin that 37.89% respectively in the Techiman accrued to a processor per month in municipality. This indicated that for value and percentage was GH¢5210 and every GH¢1 invested in processing STRUCTURE, CONDUCT AND PERFORMANCE OF THE GARI MARKET 35

activity a gross margin of 37.89% Techiman. In Techiman municipality, a accrued to processors in Techiman.Net processor handled an average of 6 KIA margin in value and in percentage was trucks (3000kg of cassava roots per estimated at GH¢2861.5 and 20.81% truck) at an average price of GH¢1400. in Techiman. A processor in Techiman The major cost items making up municipality sold an average of 55bags the processing costs were firewood, (120kg per bag) of Gari every month. peeling, grating, milling, roasting and This showed that for every GH ¢ 1 packaging totaling Gh¢2348.50.This invested in processing activity a net incurred for processing 18000kg of margin of 20.81% accrued to processors cassava roots. There was no cost item in Techiman. The cost price item for for water in Techiman since processors processors consists mainly of fresh do not wash the peeled cassava before cassava tubers costing GH¢8540 in grating and milling. 36 STRUCTURE, CONDUCT AND PERFORMANCE OF THE GARI MARKET

TABLE 5 Average monthly cost and returns of wholesalers in Mampong and Techiman

ITEM MAMPONG TECHIMAN Output 22 bags 69 bags Selling price per Unit Gh¢250 Gh¢270 A. Gross revenue Gh¢5500 Gh¢18630 Output 22 bags 69 bags Cost price per Unit Gh¢230 Gh¢250 B. Variable Cost/Cost of produce Gh¢5060 Gh¢17250 C. Gross Margin (A-B) Gh¢440 Gh¢1380 Gross margin as % of gross 8% 7.41% Revenue =(C/A)*100% Amount Amount Marketing costs Gh¢ Gh¢ Transportation cost 41.75 588.05 Loading and Offloading 15.95 212.2 Market Toll 13.8 139.3 Association dues - 12 D. Total marketing costs 71.45 951.55 E. Net Margin(C-D) 368.55 428.45 Net margin as % of Gross 6.70% 2.30% revenue =(E/A)*100%

Source: field survey (2016) From Table 5 It was realized that the which ranged from transportation, average returns for a wholesaler in loading and offloading and market toll. Mampong in value and in percentage A wholesaler’s average marketing cost was GH¢440 and 8% gross margin per month was estimated at GH¢71.45 and GH¢ 368.55 and 6.70% and net in Mampong municipality for handling respectively. A wholesaler in Mampong 22 bags (120kg per bag) of gari municipality handled 22 bags (120kg Also, a wholesaler in Techiman per bag) of Gari every month. A received a gross margin in value and in wholesaler incurred marketing costs percentage of GH¢1380 and 7.41% and STRUCTURE, CONDUCT AND PERFORMANCE OF THE GARI MARKET 37 a net marketing margin in value and in transportation, loading and offloading, percentage of GH¢428.45 and 2.30% market toll and association dues. A per month respectively. A wholesaler wholesaler’s average marketing cost per in the Techiman municipality handled month was estimated to be GH¢951.55 69 bags (120kg per bag) of Gari for handling 69 bags (120kg per bag) every month. A wholesaler incurred of Gari. marketing costs which ranged from

TABLE 6 Average monthly cost and returns of retailers in Mampong and Techiman

ITEM MAMPONG TECHIMAN Output 7 bags 13 bags Selling price per Unit Gh¢270 Gh¢290 A. Gross revenue Gh¢1890 Gh¢3770 Output 7 bags 13 bags Cost price per Unit Gh¢250 Gh¢270 B. Variable Cost/Cost of produce Gh¢1750 Gh¢3510 C. Gross Margin (A-B) Gh¢140 Gh¢260 Gross margin as % of gross 7.41% 6.90% Revenue (C/A)*100% Amount Amount Marketing costs Gh¢ Gh¢ Transportation cost 8.63 57.8 Loading and Offloading 5.25 47.53 Market Toll 6.9 26.85 Association dues - 12 D. Total marketing costs 20.78 144.18 E. Net Margin(C-D) 119.22 115.82 Net margin as % of Gross revenue 6.31% 3.07% (E/A)*100%

Source: field survey (2016) 38 STRUCTURE, CONDUCT AND PERFORMANCE OF THE GARI MARKET

From Table 6 a retailer received an 8.27% and 2.41% share of transaction average gross margin in value and in costs along the chain in the Mampong percentage of GH¢140 and 7.41% municipality respectively. Among key and a net margin of GH¢119.22 and players in the Techiman municipal, 6.31% respectively in the Mampong processors, wholesalers and retailers municipality. A retailer in Mampong had 68.19%, 27.73% and 4.19% municipality handled 7 bags (120kg share of transaction cost respectively. per bag) of Gari every month. An Juxtaposing the proportion of cost average retailer in Mampong incurred as against player’s share of margin, a monthly marketing cost of GH¢20.78 the study rejected the null hypothesis for handling 7 bags (120kg per bag) of of equitable distribution of margins Gari. There were no trade associations along the gari marketing chain. This in Mampong municipality hence there is in consonance with the findings of was no cost item for association dues. Olagunju et al. (2012). Margins are Also, retailers received a gross not equitably distributed along the margin in value and in percentage of chain relative to cost. For instance, in GH¢260 and 6.90% and a net margin in Mampong, retailers obtained 23% of value and in percentage of GH¢115.82 the net margin even though they covered and 3.07% respectively in the Techiman just 2.4% of the total transaction cost municipality. A retailer in Techiman along the chain. In the same district, municipality handled 13 bags (120kg wholesalers who incurred 89% of the per bag) of Gari every month. A transaction costs rather received 71% retailer incurred marketing costs which of the net benefit along the chain. ranged from transportation, loading and Processors in Mampong got just 5.4% offloading, market toll and association of the net margin after incurring as high dues. A retailer incurred an average as 89% of the total transaction cost monthly marketing cost of GH¢144.18 along the chain. This diaproportionate for handling 13 bags (120kg per bag) distribution of margins can threaten the of Gari. sustainability of the gari value chain in the Mampong municipality. Unlike Distribution of Margins Mampong municipality, the distribution From Fig 1 the research revealed that of margins among the key actors in the the key players being processors, gari chain was quite balanced in the wholesalers and retailers had 89.32%, Techniman municipality. STRUCTURE, CONDUCT AND PERFORMANCE OF THE GARI MARKET 39

Fig 1 Distribution of costs and Margins among key Actors in the Gari market

Source: Generated from field data (2016)

Constraints of Key Players of scale. Frequent price fluctuations Table 7 shows the constraints faced by affect processors income. Other processors in the Gari business. They pressing constraints include high cost were ranked ranging from the most of raw material, inconsistent supply pressing ones to the least ones based of raw materials and limited access to on the mean score. The most pressing firewood. The research identified other constraints for both municipalities were constraints such as heat and smoke from lack of access to credit, price fluctuations roasting the Gari, credit unworthiness and low efficiency of machines. of some customers, stench from the The lack of access to credit makes it effluence and the drudgery involved in difficult for processors to expand their the business. scale of production to enjoy economies 40 STRUCTURE, CONDUCT AND PERFORMANCE OF THE GARI MARKET

Table 7: Constraints faced by processors of gari

CONSTRAINTS MAMPONG TECHIMAN MEAN RANK MEAN RANK st nd Limited access to credit 1.2 1 1.4 2 rd st Price fluctuations 1.6 3 0.3 1 nd rd Low efficiency of machines 1.5 2 1.6 3 th th High cost of raw material 1.8 4 1.8 4 th Low dry matter of cassava 2.4 7 2.3 5th roots th th Inconsistent supply of raw 2.2 6 2.5 6 materials th th Limited access to firewood 2.0 5 2.6 7 th th High cost of transportation 2.5 8 3.6 8 th th Poor road network 2.9 9 4.7 10 Low demand for Gari 3.9 10th 4.6 9th Scale for ranking: 1=strongly agree; 2=agree; 3=neutral; 4=disagree; 5=strongly disagree Source: Field Survey (2016) Table 8 presents the various contrary, wholesalers in Techiman constraints faced by wholesalers in municipality claimed that price both municipalities from the major fluctuations, limited access to credit ones to the minor constraints. The and high cost of transportation were wholesalers reported that limited access their major constraints. Other minor to credit, high cost of Gari and price constraints were high cost of Gari, low fluctuations are the major constraints demand for Gari and poor quality of in the Mampong municipality. On the Gari. STRUCTURE, CONDUCT AND PERFORMANCE OF THE GARI MARKET 41

Table 8 Constraints faced by Wholesalers in Gari business

MAMPONG TECHIMAN CONSTRAINTS WHOLESALERS WHOLESALERS MEAN RANK MEAN RANK st nd Limited access to credit 1.1 1 1.4 2 rd st Price fluctuations 1.4 3 1.2 1 nd th High cost of Gari 1.2 2 2.3 4 High cost of transporta- th rd 1.7 4 1.5 3 tion th th Poor road network 2.4 5 2.4 5 th th Poor quality of Gari 2.6 6 2.5 6 Inconsistent supply of th th 2.7 7 2.7 7 Gari th th Low demand for Gari 3.5 8 3.7 8

Scale for ranking 1=strongly agree 2=agree 3=neutral 4=disagree 5=strongly disagree Source: Field Survey (2016) Table 9 presents the various constraints in Techiman municipality claimed that faced by retailers in both municipalities price fluctuations, limited access to from the major ones to the minor credit and high cost of transportation constraints. The retailers reported were their major constraints. Other that limited access to credit, price minor constraints were high cost of fluctuations and high cost of Gari were Gari, low demand for Gari and poor the major constraints in the Mampong quality of Gari. municipality. On the contrary, retailers 42 STRUCTURE, CONDUCT AND PERFORMANCE OF THE GARI MARKET

TABLE 9 Constraints faced by Retailers in Gari business

CONSTRAINTS MAMPONG RATAILERS TECHIMAN RETAILERS

MEAN RANK MEAN RANK

st nd Limited access to credit 1.3 1 1.4 2

nd st Price fluctuations 1.6 2 1.2 1

rd th High cost Gari 2.5 3 2.3 4

th rd High cost of transportation 2.7 4 2.2 3

th th Inconsistent supply of Gari 2.9 5 2.9 6

th th Poor road network 3.5 6 4.2 8

th th Poor quality of Gari 3.6 7 3.7 7

th th Low demand for Gari 3.9 8 2.4 5

Scale for ranking 1=strongly agree 2=agree 3=neutral 4=disagree 5=strongly disagree

SUMMARY, CONCLUSION for their texture and colour. Analysis AND RECOMMENDATIONS of the market structure revealed that Summary and Conclusion there was no barrier to entry except The study examined the Gari market for Techiman market where permision structure. The study found that the from the market queen before operation structure of the market for Gari served as a barrier. wholesaling and retailing are almost The study revealed that in terms perfectly competitive in nature. of conduct, market players depend However, Gari processing industry largely on the forces of demand and is weak oligopolistic in nature. This supply and cost of acquisition plus was based on figures from Market margin to set prices of Gari and raw share ratio and Herfindahl-Hirschman material. Gari traders association exists Index (HHI) of key players along the only in the Techiman market. However, chain. There was low level of product the association does not interfere in the differentiation in the Gari market except trading business but it exists largely for STRUCTURE, CONDUCT AND PERFORMANCE OF THE GARI MARKET 43

welfare purposes. The study concluded Recommendations that the gari business is profitable To enhance market performance in both municipalities. A typical and conduct of actors in the gari processor received a monthly gross industry, improved and more efficient margin of GH¢1662 (34.78%) and processing equipment should be GH¢10765 (83.45%) in Mampong and provided at the community level by Techiman municipalities respectively. central government and development Net margin of GH¢890.02(18.65%) partners. To ensure consistency and and GH¢8416.50(65.24%) were also product traceability, there is the obtained in Mampong and Techiman need for product differentiation and municipalities respectively by innovation through proper packaging, processors. Retailing and wholesaling labelling and value addition for niche segments of the gari market chain markets. There should be formation were equally profitable. However, and nurturing of formidable trader net margins were not equitably associations in the industry to improve distributed among key players in the bargaining position in the market and gari market chain, especially in the also, to facilitate linkages and strategic mampong municipality. This finding alliances with institutional buyers has very serious implications for and other stakeholdes in the broader the sustainalbility of the gari value enabling business environment. Such chain in Mampong if steps are not associations should also be encouraged taken to address the imbalance in the to pool resources together through distribution of margins. The most microcredit/susu schemes to support pressing constraints among processors members with credit facilities at were found to include limited access concessional interest rates. Finally, to credit, price fluctuations and low storage facilities should be provided efficiency of processing equipment. by various trader associations in the Traders reported limited access to gari market to ensure proper storage of credit, inconsistent supply of Gari, high excess Gari during peak season. This transportation cost and fluctuations in will ensure that key market participants price as their major constraints. receive stable prices throughout the year since supply of gari on the market would be very well regulated when improved storage facilities are available. 44 STRUCTURE, CONDUCT AND PERFORMANCE OF THE GARI MARKET

REFERENCES

Afolabi J.A., (2009). An assessment of Gari Marketing in South-Western Nigeria.Journal for Social sciences. Vol 21(1).pp 33-38 Awol Zeberga, (2010). Analysis of Gari Market Chain: the case study of Dale and Alaba Special Woredas of SNNPRS, Ethiopia. A master’s thesis submitted to Harmaya University. Delgado C., (1995). African Changing Agricultural Economics and Agribusiness, 2nd edition. McGraw Hill Book Company.IFPRI. Kohl’s, R.L. and Uhl, J.N., (1985).Marketing of Agricultural Product. Fifth ed., Coiler Mac, Milan, U.S.A. Kotler, P. and Armstrong, G., (2003). Principle of Marketing, 10th Edition.Hall of India Pvt. Ltd., New Delhi. pp 5-12. K. Mylene, and J. Kirsten (2001). The New Institutional Economics: Applications for Agricultural Policy Research in Developing Countries. MSSD Discussion paper No. 41. International Food Policy Research Institute. Nzima W. M., Dzanja J., Kamwana B., (2014). SCP of Groundnut Markets in Northern and Central Malawi: Case studies of Mzimba and Kasungu districts. International Journal of Business and Social Sciences.Vol 5. No. 6 Olagunju F., Babatunde R., Salimonu K., (2012). Market Structure, Conduct and Performance of Gari processing Industry in South Western Nigeria. European Journal of Business and management. Vol 2.No. 2 Okpeke M.Y. and Onyeagocha S.U.O. (2012). Analysis of Processing Cassava Tubers into Gari in Isoko North local government area of Delta state, Nigeria. European Journal of Agriculture and Forestry Research, Vol 3. No. 5 pp 15-25. Osei-Mensah J, AidooR, Boakye-Yiadom, S. Jnr., Mensah R, Danquah A.O, Amankwah A.A, Biney F, (2013). Analysis of Production and Marketing Constraints, Consumer Preferences and Decision to Purchase Gari Mix in the Kumasi Metropolis of Ghana. International Journal of Agriculture Innovations and Research 2013.Volume 2, No.1 pp.49-54 Issued, ISSN, (online) 2319-1473. Opoku-Mensah S, Agbekpornu H, Wongnaa C. A.,(2010) Economic returns of Gari Processing Enterprises in the Mampong Municipality, Ghana. International Journal of Agriculture Innovations and Research 2013.Volume 2, No 4 pp 502- 509. 45

TRUST, GOVERNANCE, UPGRADING AND MARKET POWER IN THE CASSAVA VALUE CHAIN OF SOUTHERN GHANA

Isaac Manu, Akwasi Mensah-Bonsu, Henry Anim-Somuah and Yaw B. Osei-Asare Department of Agricultural Economics and Agribusiness, University of Ghana, Legon.

Abstract Herfindahl-Hirschman Index (HHI) Currently, the cassava crop is transiting to assess the market power. Gari and from a staple food commodity into an agbelima processing presents the industrial crop for the production of most important market channel for starch and ethanol and this suggests smallholder farmers, while, ethanol, probable changes in marketing cassava starch, industrial flour and high arrangements and conditions. Thus, quality flour processors are important understanding the various outlets of market channels for large-scale cassava cassava products and the nature of the farmers. value chain are important. The results obtained for level of The paper assesses the nature trust relationships along the cassava of trust, governance, upgrading and value chain were mixed: some of market power in the cassava value the indicators suggest a high trust chain in Ghana. The value chain actors relationship among actors along the interviewed include cassava farmers chain, others suggest otherwise. Among and small-scale (gari and agbelima) the various indicators of trust, a verbal processors who were selected randomly contract is predominant for cassava and large-scale cassava processors, farmers and small-scale processors, purposively sampled from the Volta, while large-scale processors engage Eastern and Central regions of Ghana. in written contract with their buyers. The study describes uses percentages The majority of cassava farmers to describe the nature of trust, type of (90%), agbelima processors (73%) governance structure, and upgrading and gari processors (77%) do not along the value chain. It uses the receive assistance on new technology, 46 TRUST, GOVERNANCE, UPGRADING AND MARKET POWER

indicative of low trust relationship, but farmers and small-scale processors all the large-scale processors receive is also necessary to ensure process, assistance on new technology shows product and functional upgrading. high trust relationship. Farmers and small-scale processors Generally, the findings suggest should be given technical and credit that captive market and modular support, which could help in modernize governance structures exist between the cassava value chain in the long term. cassava farmers and their buyers, small- Introduction scale (gari and agbelima) processors and Agriculture is important to the their buyers and large-scale processors development of Ghana, particularly and their buyers, respectively. These crucial for reducing poverty (Cervantes- results imply that while farmers can Godoy & Dewbre, 2010). While be exploited, the small and large-scale agriculture contributes 52% of the processors cannot be exploited by work force in Ghana, the service and their buyers. The process of product industry sectors contribute 29% and upgrading is slow among smallholder 19% respectively (Ghana Statistical farmers, while it is high among large- Service, 2013). scale producers. The manufacturing sector The estimates of the HHI for depends on the agricultural sector cassava farmers and small-scale for raw materials in the production processors are low, suggesting low process, with usage of agricultural raw market power and thus, their inability material by the manufacturing sector to influence the price of their respective going beyond the agri-food and fibre products. These markets are not sector to the ethanol, biodiesel and concentrated. However, estimate of polymers sectors (Boehlje & Bröring, the HHI for large-scale processors is 2011). In the Food and Agriculture very high, suggesting their market is Sector Development Policy (FASDEP concentrated. The study recommends II), Ghana’s strategies to generate a policy to increase production should economic activities from agriculture focus on improving the capacity of includes, increased access to market, small-scale processors who represent value chain development, improved a less concentrated segment of the competitiveness of production and value chain and a major market for institutional support (Ministry of Food smallholder farmers. and Agriculture, 2007). Improvement of the capacity of TRUST, GOVERNANCE, UPGRADING AND MARKET POWER 47

Cassava has been a traditional Post-harvest losses in cassava staple food crop for households in affect all actors in the cassava value Ghana. The crop has today also become chain. Value chain actors such as small- an industrial crop in the production scale processors, industrial processors, of starch and ethanol (Adjei-Nsiah traders, transporters, retailers and & Sakyi-Dawson, 2012). There is consumers are all confronted with the potential for the use of cassava dealing with the challenge of high post- products by the brewery industry in the harvest losses (Knipscheer, Ezedinma, production of cassava-based beer (Kleih, Kormawa, Asumugha, Makinde, Phillips, Wordey, & Komlaga, 2013). Okechukwu, & Dixon, 2007). The It is important that Ghana continues challenge of high post-harvest losses to increase cassava production to feed attributed to low value addition and its inhabitants as well as its industries use of cassava in West Africa. In Brazil, with the hope of improving the standard cassava use is about 50% of animal feed, of living of value chain actors. This is while in West Africa cassava use is for because cassava will continue to play animal feed is only between 5-15% an important role in the development (Kariuki, Ochugboju, & Kottoh, 2013). of the country in terms of employment Adjekum (2006) identifies insufficient creation and poverty reduction. market channels in the cassava value Lose Cassava once harvested is a chain as a major constraint to chain highly perishable product and without actors in Ghana, noting that it leads to any kind of value addition, cassava low prices of cassava and its derived easily loses its economic importance products and therefore affects the (Bokanga, 1999). Naziri, Quaye, profitability of activities in the value Siwoku, Wanlapatit, Viet Phu and chain. Bennett (2014) in a study comparing However, recent studies suggest the diversity of post-harvest losses in that new market channels have emerged the cassava value chains in selected from the cassava value chains, presenting developing countries (Ghana, Nigeria, new opportunities for value chain actors Thailand and Vietnam), revealed that in Ghana. Currently, the use of the crop Ghana had the highest post-harvest in Ghana has gone beyond the food losses of 21.2%. This is attributed to sector, into the manufacturing sector, low value addition at the farm gate, as where cassava is processed into starch most harvested cassava tubers get to and ethanol (Adjei-Nsiah & Sakyi- consumers in the raw state in Ghana. Dawson, 2012). Kleih et al.(2013) also 48 TRUST, GOVERNANCE, UPGRADING AND MARKET POWER

identify processing of cassava into high the nature of the cassava value chains, quality cassava flour, industrial flour, given the emerging opportunities, is cassava chips and animal feed, among important. To explore this issue, the other products, as new market channels present study examines the nature for cassava in Ghana and add that the of trust, governance, upgrading and brewery industry also presents another market power (concentration) in the market channel for cassava-derived cassava value chain in Ghana. The products for the production of cassava specific research objectives of the study beer in Ghana. are: (i) to describe the market channels The Statistics, Research and for the cassava value chain; (ii) to Information Directorate (SRID, 2014) describe the nature of trust, governance report for the 2013/14 crop year stated and upgrading along the cassava value that the crop had a surplus production chain and (iii) to estimate the market of 7,151,262 metric tonnes, which power or concentration in the cassava represents about 44.72% of gross value chain. biological production of cassava for Brief Review of literature on the crop year. Koyama, Kaiser, Ciugu trust, governance upgrading and Kabiru (2015) explain that the and market power excess production, of 30% to 40% of Marketing channels and cassava produced in Ghana, presents distribution in an agri-food a huge opportunity for value addition marketing system and development of the cassava – value The terms market and distributional chains. Koyama et al. (2015) further channels could be used synonymously argued that the income of cassava (Szopa & Pękała, 2012). Each shows farmers could be improved by 50% to the movement of products from the 300%, when they are integrated into manufacturer or producer to the off- other (new) market channels. This taker or buyer and involves agents and would also lead to yield improvement other market participants. Szopa & through increased use of agro-inputs. Pękała (2012)note that functionally the The forward and backward channel includes not only the flow of linkages of cassava production to the products, but also change in ownership non-farm sector that is emerging through and information about the business existing and new market channels will environment and about risk. Atanasoaie have economic implications for value (2011) states that farmers’ choice of a chain actors. Thus, a study to understand particular channel is important and TRUST, GOVERNANCE, UPGRADING AND MARKET POWER 49

includes the options to choose a direct influence the transformation of channel without the participation of marketing channels. Kirimi, Sitko, marketing agents or indirect channels Jayne, Karin, Sheahan, Flock and Bor with the participation of marketing (2011) found out that the liberalization agents, with their associated merits of the Kenya’s maize sector led to a and demerits. However, the scale of transformation of the maize marketing production and the nature of the market channels, and this resulted in increased should inform the choice of marketing market participants, increased channel, among others (Atanasoaie, competition and a diversity of potential 2011). market channels that small-scale Marketing channels of an agri- maize farmers have to sell the maize food system that involve only the flow their produce. They report that the of products from the farmer, processor primary assemblers were compelled to and retailer have changed, and the purchase maize in very remote areas focus now is on establishing long- on time, while their major off-takers term business relationships between (wholesalers) paid the assembler to chain actors in the agri-food sector perform their function effectively and (Shepherd, 2007). The facilitating this has led to a reduction in the margin factors include high demand for food between assembler and the wholesaler. quality, safety and changes in income Trust (Shepherd, 2007). Musso (2010) also Trust which has been defined as ‘the identifies key elements that could lead extent to which one believes that to changes in marketing channels to others will not act to exploit one’s include changes in demand of product, vulnerabilities’ (Morrow, Hansen, & new expectation requirements for Pearson, 2004, p. 50), has assumed products, technological changes that importance in economics and sociology influence the relationship between for a number of reasons (Vieira, Paiva, chain actors and the type of competition Finger, & Teixeira, 2013). Coulson in the chain. Caiazza and Volpe (2012) (1998) notes that trust is needed for the report an increase in the level of success of firms in the value chain. It is competitiveness of markets within the an engine to the internal and external value chain with shift in focus to cost performance of firms and helps to reduction to increase profit margins reduce the operational cost of firms, without compromising on quality. while strengthening inter-firm linkages Government policies also 50 TRUST, GOVERNANCE, UPGRADING AND MARKET POWER

and relations (Coulson, 1998). leadership and a scale in a value Using descriptive statistics, chain, there will be no cooperation Masuku and Kirsten (2003) report that between value chain actors. Kaplinsky trust is important in the improvement and Morris (2000) state that trust is a of cooperation among participants determinant of the value chain leaders’ in a supply chain and yields better control of the value chain and the future performance in an organization than sustainability of a value chain is based binding agreements. Contracts among on trust building. market participants affect the ability Handfield and Bechtel (2002) of chain actors to benefit from new in a study on the role of trust and the dynamics in the market. They note relationship structure in improving that trust based relationships including supply chain responsiveness using truthfulness and absence of exploitation the structural equation model, suggest between processors and sugar cane that a legally binding written contract growers help to improve performance can be an impediment of trust, while of market participants. Masuku and informal verbal agreements on delivery Kirsten (2003) also note that trust schedules, payment terms and pricing improves the obligation of chain actors, enhance trust in relationships among reduces the cost of monitoring and chain actors. Bouckaert, Laegreid and enhances efficiency in the value chain. Van de Walle (2005) add that the use The study further reveals that both of contracts gives indication that there farmers who trust the millers is no trust between firms in a chain. and those who do not trust the millers Using confirmatory factor analysis are aware of the importance of building in a study on trust and supplier-buyer relationship. The majority (90.6%) who relationships, Vieira et al. (2013) did not trust the sugarcane millers were found out that cooperation, effective of the opinion that the millers exploited communication between supplier and them. buyer is positively related to trust Webber and Labaste (2007) note (building). In addition, the ability to that the pivot on which the development meet delivery schedules influence trust. of a value chain takes place is trust. It However, they also revealed that the is essential to enhance the relationship flow of information is not a sufficient between the value chain actors for the condition for the existence of trust development that benefits all. They between supplier and other chain actors. argue that without trust, information, Humphrey, Kaplinsky, & TRUST, GOVERNANCE, UPGRADING AND MARKET POWER 51

Saraph(1998) categorise chain this regard, Swinnen, Vandeplas and actors’ conduct in relation to trust as Maertens (2007) note that the type of follows: (i) length of contracts; (ii) governance can lead to growth, food ordering procedure; (iii) contractual security and poverty reduction in relationship; (iv) modes of inspection Africa and advocate for mechanism to used in accepting incoming materials; increase prices of staple foods in Africa (v) degree of dependence among chain to ensure the development of value participants; (vi) types of technical chains through appropriate governance assistance; (vii) nature and methods of system. communication along the chain; (viii) Various methods have been used determination of prices; (ix) credit in analysing the governance structure extended along the chain; and (x) mode in a value chain. Gereffi, Humphrey of payment to external producers. These and Sturgeon (2005) analysed the type indicators of trust building are used in of governance found in a value chain the present study. using three key elements. These are complexity of transaction, ability to Governance of a Value Chain codify transaction and capabilities in the Frederick (2014, p. 7) stated ‘governance is about power and the ability of a firm supply base. They further categorized (or organization or institution) to exert governance into five aspects, which are control along the value chain by setting as follows: and/or enforcing parameters under which others in the chain operate’. 1. Markets: In this type of value chain governance the seller may or may not Humphrey & Schmitz (2000) identify produce to a particular specification. three types of governance: network, The tendency for the seller to switch quasi-hierarchy and hierarchy. Network to another buyer is high. The level of depicts equal power balance in the interdependency among value chain governance structure, while quasi- actors is also low. hierarchy shows a governance structure 2. Modular value chains: Suppliers to a in which one element/component is modular value chain produce according superior to the other. Bitran, Gurumurthi, to a specific quality standards. In the & Sam (2006) state that organizations provision of turn-key services, suppliers are moving from the hierarchical bear full responsibility of activities one sided governance system to the involved. The supplier can even pre- network system of governance, with finance the activity. the focus now on partnership. In 3. Relational value chains: There is 52 TRUST, GOVERNANCE, UPGRADING AND MARKET POWER

high interdependency and relationship are the modular, relational and captive between buyer and seller. Trust, spatial are in the middle of the continuum, proximity and reputation play critical similar to Gereffi, Humphrey and roles in relational value chains. These Sturgeon’s (2005) categorization of chains could also be influenced by governance structure. family and ethnic relationships. A Hammervoll (2011) in a study on relational value chain takes time to ‘governance of value creation in build. supply chain relationships’ and using 4. Captive value chains: In this the structural equation model states governance structure, one value that the relational governance system chain actor is dependent on the other. was the best in terms of knowledge and Most often, the small market supplier information sharing. Ji, Felipe, Briz depends on the large buyer. The large and Trienekens (2012) in an empirical buyer dictates the price, the quantity study on governance structure and the standards and thus controls the choices in China´s pork supply chain small supplier. from the perspective of transaction 5. Hierarchy: This is the top to cost economics and transaction bottom approach of governance. It is value analysis state that the market characterized by the superior giving relationship governance structure direction to the subordinate. It could also exists between smallholder pig farmers be instructions from the headquarters of and smallholder slaughterhouses. an organization to its divisions or units. They conclude that the value chain Dunn and Villeda (2005) in analysing participants had full knowledge about the governance structure of a value chain each other, which therefore influences assumed that a continuum indicates the type of the governance structure. vertical relationships between firms. Upgrading of a Value Chain The type of association between firms Upgrading entails improvement of a determines the governance structure of value chain activity from the perspective a value chain. At one extreme end of the of product quality, cost efficiency and the continuum is a market relationship with skills of value chain actors (Pietrobelli limited interaction between firms. The & Rabellotti, 2004). Mitchell, Coles other extreme end of the continuum is and Keane (2009) clarify upgrading hierarchical relationships in which the as the process where value chain value chain has an owner who gives participants acquire the necessary skills direction. The network relationships that TRUST, GOVERNANCE, UPGRADING AND MARKET POWER 53

in technology to improve market and upgrade to add more activities. Under institutional capacity to enhance their some situation, the participant may take efficiency. Upgrading allows value chain over the entire value chain. participants to perform a higher value Market power and concentration adding activity. Mitchell et al. (2009) play important roles in driving identify seven upgrading strategies. innovation in the value chain. Large These are horizontal coordination, firms have the needed resources to push vertical coordination, functional for process and product upgrading. The upgrading, process upgrading, product aim is to introduce new products and upgrading, inter-chain upgrading and rebrand existing ones through packaging enabling environment upgrading. (Riedel, Bokelmann, & Canavari, Humphrey (2004) states that the 2009). Dunn and Villeda (2005) assert strategies for upgrading does not only that the type of governance could also need improvement of competencies but affect the nature of upgrading in a also the establishment of relationship value chain among medium and small between market participants. Thus, it is enterprises. They emphasize that value important to demonstrate the effect of chain actors in a captive relationship value chain relationship on upgrading could benefit from technology that can the acquisition of new knowledge and lead to process upgrading. In addition, technology. modular, relational and captive Humphrey and Schmitz (2000) facilitates product upgrading. identify three issues regarding Neven (2014) states that upgrading in a value chain. The first consumers determined value. This issue is upgrading regarding production. implies that consumer demand In this issue domestic value chain actor, influence upgrading in a value chain. learn new knowledge on improvement Consumer’s ability to pay extra for in production and quality. The improved product quality has been a second issue arises because of buyer driver of value chain upgrading. An succession. Producers produce for a innovation that encourages efficient low market at the initial stage and move production, productivity and reduced on to produce for a complex market wastage facilitates upgrading in the with high demands. The third issue value chain. identified is the functional upgrading where a participant undertakes a particular activity in a value chain but 54 TRUST, GOVERNANCE, UPGRADING AND MARKET POWER

Market power Saitone, & Sexton (2012) in a study Individuals, groups and firms acting of U.S farm product markets used jointly can exercise market power the Herfindahl Hirchman Index (White, 2012). It shows the extent and four-firm concentration ratio to which prices are determined by (CR4) to measure market power and a firm or group of firms. In a perfect concentration, respectively and found competition, every market participant a positive relationship between market is a price taker and there is homogenous power and level of concentration. A product. This does not happen when buyer with a higher market power can there is an exercise of market power lower input prices, while, a higher (White, 2012) . market power of the seller lead to An issue arising in the higher product prices (Swinnen & understanding of market power is that Vandepla, 2009). Market power affects firms that determine the price, quantity the efficiency and equity of distribution and quality standards lead numerous of value added in a chain. Riedel et al. markets (Tirole, 2014). Market power (2009) emphasized that with market in a value chain relates to benefits and power, a value chain actor can decide risks shared by value chain participants on the supplier it wants to participate and includes the behaviour of the in the value chain, the sharing of role lead firm regarding the compliance to and the arrangement of production. standards (Webber & Labaste, 2010). The use of market power is for profit Porter (2008) noted that knowledge maximization. Different participants in of the factors influencing market the value chain are exposed to varying power could give an indication of the degree of risk depending on the power current and future profitability and position. competitiveness of a firm. Market power Using a linear simulation model indicates the level of control a firm has to measure the effect of market power in on an industry locally or globally (Wu, the corn sector and it impact as a result Bose, Wierman, & Mohsenian-Rad, of ethanol subsidy, Saitone, Sexton and 2013). Sexton (2008) revealed that the abuse Swinnen and Vandepla (2009) of market power reduced the growth of stated that market power is associated the corn production. They noted that with concentration, where a higher production of corn would have increased concentration could lead to higher without the exercise of market power market power and vice versa. Crespi, under perfect competition. Sexton and TRUST, GOVERNANCE, UPGRADING AND MARKET POWER 55

Zhang (2001) assessed of market power opinion, noting that Lerner’s Index in the U.S. food industry revealed that is also an indirect measure of market the effect of the abuse of market power power. They note that estimating by the oligopolist was more intense than market power using the index requires same exercise of market power by the three important assumptions, namely oligopsonist. The existence of both the assumptions on input and output prices oligopolist and oligopsonistin a market and the cost functional form to estimate leads to severe welfare losses to other econometrically the marginal cost, actors in the market. which could lead to wrong estimations. The use of concentration ratios Leon (2014) adds that the Lerner and the Herfindahl–Hirshman Index index has considerable theoretical and (HHI) have been adopted severally for analytical weaknesses. He notes that assessing market power of firms, though deviation of price from marginal cost they represent indirect measurements relates more to the efficiency of the firm of market power (Kovács, 2011). than the abuse of market power. The use of Herfindahl–Hirshman METHODOLOGY Index to measure market power Methods of Analysis ignores the transmission challenges Analysing the market channels of the on the market (Lee, Baldick, & Hur, cassava value chains 2011). According to Carbo-Valverde, The study conducted a value chain Rodríguez-fernández and Udell (2006) mapping using an organogram to a direct measurement of market power examine the market channels of the entails the use of the Lerner’s Index. cassava value chains. Percentages were The Lerner’s Index measures how far used to express the distribution of the the price of a product deviates from the cassava-derived products along the marginal cost of production, indicating channels. the mark-up to marginal cost because of market power (Carbo-Valverde et al., Analysis of the nature of 2006) the cassava value chains The Lerner Index has advantages i. Trust over the HHI because it provides a To conduct an analysis of trust in the more direct measure of market power, cassava value chain, the study adapted consistent and robust compared to HHI the indicators of trust by Humphrey, (Carbo-Valverde et al., 2006). Yaldiz Kaplinsky, & Saraph (1998). Indicators and Bazzana (2010) are of a different of trust used for the study are length of 56 TRUST, GOVERNANCE, UPGRADING AND MARKET POWER

trading relationship, contract, ordering iii. Governance in the cassava value procedure, inspection, payment chain duration, price determination, degree The study used combinations of low or of dependence, technical assistance, high measure for three key indicators credit assistance and frequency of to describe the types of governance communication. The study used structure for the cassava value chain. percentages to describe trust relations The three indicators used, namely along the cassava value chain. complexity of transaction, ability to Percentages lower than 50% for each transmit information efficiently and indicator of trust characterize low trust the capacity to meet requirement of relations, percentages equal to 50% transactions, have been adapted from suggest moderate trust relations, while Gereffi, Humphrey and Sturgeon percentages greater than 50% for each (2005). The study assessed the indicator of trust characterize high trust complexity of transaction, ability to relations. Length of trading relationship transmit information and the capacity greater than two years represents high to meet requirements of transaction as trust relation, while, those less than or follows: equal to two years signifies low trust (a) The complexity of transaction relations. was assessed through the number of ii. Upgrading processes involved for transaction The indicators for upgrading used in to be completed. Low complexity the present study are process, product, of transaction is characterized by functional and inter-chain upgrading in transaction involving not more than the cassava value chain. Percentages two processes for completion, while, were used to assess the type of high complexity of transaction entails upgrading seen in the value chain for more than two processes for transaction each indicator. A percentage lower than to be completed. 50% for an indicator characterizes low (b) The ability to transmit or upgrading, equal to 50 for an indicator codify information was assessed characterizes moderate upgrading, through the frequency and medium of while a percentage greater than 50% communication between chain actors. for an indicator characterizes high (c) The capacity of an actor to upgrading. meet requirements of transaction was assessed through the ability to meet TRUST, GOVERNANCE, UPGRADING AND MARKET POWER 57

quantity and quality requirements of indicator greater than 50% will buyers. characterize high for a particular The study used percentages governance type. to determine whether an indicator The details of the decision rule of governance as measured is high, for the type of governance in the moderate or low. The following cassava value chain are presented in benchmarks establish an indicator of Table 1: A market governance structure governance type: is characterized by low complexity of (d) Average percentage of an transaction, high ability to transmit indicator less than 50% will characterize or codify transaction information and low for a particular governance type. high capacity to meet requirements of transaction. A captive governance (e) Average percentage of an structure is characterized by high indicator equal to 50% will characterize complexity of transaction, high ability moderate for a particular governance to transmit information and low capacity type. to meet requirements of transactions. (f) Average percentage of an Table 1: Determination of the type of Governance in a Value Chain Capabilities Governance Complexity of Ability to codify Power in the supply Type Transaction transaction Asymmetry base

Market Low High High Low Modular High High High Low Relational High Low High Low Captive High High Low High Hierarchy High Low Low High Source: Adapted from Gereffi, Humphrey and Sturgeon (2005)

Analysis of Market Power for cassava value chains is not defined The study uses the Herfindahl- (marginal costs and product prices along Hirschman Index (HHI) to measure the chain are not well estimated). The market power in the cassava value Herfindahl-Hirschman Index (HHI) is chains. It used the Herfindahl- measured by first estimating the market Hirschman Index because the market share that is given as: 58 TRUST, GOVERNANCE, UPGRADING AND MARKET POWER

high quality cassava flour processors, gari processors and agbelima processors. Pre-tested structured x 100 (3.1) questionnaires were used to gather relevant information of the cassava Then, the HHI is estimated by taking the value chain for the analysis. sum of the squares of the of the market Cassava starch manufacturers, share of value chain participants as: cassava starch cake and high quality = 2 + 2 + + 2 S1 S 2 ...... S n cassava flour processors were

(3.2)Where Si = percentage market purposively selected. The Dutch share of individual firm (i) Agricultural Trading Company The decision rule for an estimated (DADTCO), Mabert Seed Company HHI is: Limited, Caltech Ventures Limited and (i) A Herfindahl-Hirschman Index the Ayensu Starch Factory all provided lower than 1000 will represent an data for the study. unconcentrated market. This implies The field survey was undertaken a participant in that market cannot in three districts, namely Akuapem influence the price of the product. North, Awutu Senya and Ho Municipal (ii) A Herfindahl-Hirschman Index in the Eastern, Central and Volta regions, between 1000 and 1800 will represent a respectively, which were purposively moderately concentrated market where selected. The purposive selection of the a market participant may sometimes districts was informed by the presence influence the price of a product. of cassava-derived product value-chain (iii) AHerfindahl-Hirschman Index actors in the districts. The random greater than 1800 will represent a sampling technique was used to sample highly concentrated market. In this 301 cassava farmers from these three case, a market participant has the power districts. In addition, 20 each of gari and to influence the price of a product. agbelima processors were randomly Data Collection selected from the three districts. Details The data were collected from cassava of the value chain actors interviewed farmers, cassava cake manufacturers, are presented in Table 2. TRUST, GOVERNANCE, UPGRADING AND MARKET POWER 59

Table 2: Cassava value chain actors sampled

Processors sampled Farmers Communities where farmers were sampled with District sampled Small Large sample size in brackets scale scale

Asenema (50) Akuapem Camp (25) North 99 40 0 MintahKrom (24)

AkoefeAvenui (21) Hodzo (17) Ho Municipal AkoefeGadza (17) 102 40 3 Tanyigbe (24) Tokokoe (23)

Akumatom (25) Manfi (26) Ewutu Senya 100 40 1 Kwasiadri (27) Okuampa (22) Total 301 120 4

RESULTS AND DISCUSSIONS Table 3 presents the socioeconomic Socioeconomic characteristics of characteristics of the cassava farmers cassava farmers and small-scale and small-scale processors. processors Table 3: Socioeconomic characteristics Socioeconomic Farmers Agbelima Processors Gari Processors Characteristics Gender: Male=76.7% Female=100% Female=100% Female=23.3% Age (yrs) 44.41 40.15 44.12 Household size 6 Marital status Married=76.1% Married=95% Married=83.3% Others= 23.9% Others= 5% Others= 16.7% Years in farming/ 16.24 12.35 18.93 processing Primary occupation Farming=99.7% Processing=70% Processing=81.7% Artisan=0.7% Others=30% Others=18.3% Educational level No education=16.3% No education=26.7% No education=5.0% completed Primary=21.3% Primary=10.0% Primary=25.0% JHS//Middle=55.5% JHS//Middle=60.0% JHS//Middle=58.3% SHS=5% SHS=3.3% SHS=8.3% Tertiary=2% Tertiary=0.0% Tertiary=3.3% Source: Field Survey, 2016 60 TRUST, GOVERNANCE, UPGRADING AND MARKET POWER

The majority of farmers interviewed years working in the cassava-derived were male (76.7%). Over 70% of product value chains. Farming and farmers and agbelima processors had a processing of gari and agbelima was form of basic education from Primary a primary occupation for most of the to Middle/Junior High School. In respondents. addition, 90% of gari processors had a Market channels and Conduct form of education from primary to the of Key Market Participants tertiary level. Only 16.3% of farmers for the Cassava Value Chains interviewed had no formal education, Figure 2 presents an illustration of the while about 27% of the agbelima market channels for cassava and its processors had no formal education. derived products.Market channels in The mean age of farmers in the study the value chain areas was about 44 years, while those About 21 market channels were of gari and agbelima processors were identified for cassava value chains about 44 and 40 years respectively. in Figure 2. The study revealed that Processing of gari and agbelima is a gari and agbelima processing present female dominated activity. The majority major market channels for smallholder of the respondents interviewed were farmers. married and have spent more than 12

Figure 2: Market channelsfor the cassava and derived product TRUST, GOVERNANCE, UPGRADING AND MARKET POWER 61

It came out from the study that 46.5% of the study show that high quality of the cassava produced by smallholder cassava flour processors’ purchase farmers are purchased by agbelima 40% of the cassava produced by processors, while, 32.9% of cassava large-scale farmers. Cassava starch produced by smallholder farmers and ethanol processors accounts for are purchased by gari processors. 33% and 22% of cassava produced In addition, marketing agents buy by large-scale farmers, respectively. about 20% of the cassava produced Only 5% of cassava produced by large- by smallholder farmers, while the scale producers is used for industrial remaining, 0.7%, are sold to others, flour production. This implies that like directly to consumers. Marketing high quality cassava flour and cassava agents sell about 5% of the raw cassava starch are important market channels to starch, ethanol, high quality cassava for large-scale farmers. flour and industrial flour processors. In assessing the market channel An analysis of the market channel for ethanol, the study found that the for agbelima shows that the majority major off-taker for ethanol is a distiller (83.3%) of the agbelima produced named Kasapreko Company. The is purchased by wholesalers in the Company is a minority shareholder cassava product value chain, while, of Caltech Ventures, the only ethanol 15% is purchased by retailers. Only producer in the value chain. However, 1.7% of the agbelima produced in the Air Liquid Limited purchases carbon chain is bought directly by consumers. dioxide, a by-product in the production On the other hand, the results show of ethanol, from Caltech Ventures. that the majority (66.7%) of the gari Carbon dioxide represents a major produced is purchased directly by value addition in the chain. consumers, while, 30.0% is purchased The major buyer of cassava starch by wholesalers. Retailers buy only produced by Ayensu Starch Company 3.3% of the gari produced directly from is the brewery Guinness Ghana the processor. Limited. Ayensu Starch Company The study revealed that the key has a signed contract with Guinness actors along the market channel for Ghana Limited as the sole supplier of large-scale cassava producers and cassava starch, used in the production outgrowers are the cassava starch, of beer. This implies that any breach ethanol, high quality cassava flour and in the contractual agreement could industrial flour processors. The results lead to the collapse of Ayensu Starch 62 TRUST, GOVERNANCE, UPGRADING AND MARKET POWER

Company since it has only one buyer. processing plant. In addition, it has For example, the Dutch Agricultural 15 outgrowers and relies heavily on Trading Company, considered in the large-scale cassava producers outside present study, has collapsed because its its base at Hodzo, in the . only off-taker, Accra Brewery Limited The Company’s involvement in the stopped sourcing cassava starch cake production of cassava from its own from them. farm is to ensure a regular supply of The market channel for high cassava as raw material to support its quality flour is, however, diverse. The diversified output of ethanol, carbon study revealed that 81% of the high dioxide and high quality cassava flour. quality flour producedis sold to Accra Ayensu Starch Company Brewery Limited for the production Ayensu Starch Company Limited has of cassava beer. The agri-food sector acquired 2,000 hectares of cassava represents another source of market for farm to feed it processing plant. In high quality cassava flour, where about addition, it has established 2,500 15% of the high quality flour produced outgrowers and buys from individual is sold to bakeries and restaurants. In cassava farmers. The company has addition, 4% of the high quality flour terminated its agreement with Maxpo produced is exported. that was its sole agent for the supply The study found that the market of cassava. This implies that Ayensu channels for industrial cassava flour Starch Company Limited will in the are the plywood and mosquito coil future secure its source of raw material producers. It came out from the for the production of cassava starch study that 84% of the industrial flour from its own field and its outgrowers. produced is sold to Volta Forest, a plywood manufacturing enterprise, Mabert Seed and the remaining 16%, is sold to Company Limited Beatex Company for the production of Mabert Seed Company Limited has mosquito coils. 50 hectares of cassava farm to feed it processing plant. The Company has Conduct of Key Market an established 25 outgrowers and buys Participants Caltech Ventures raw cassava from individual farmers to Caltech Ventures Limited has 3,000 support the production of high quality hectares of cassava farm to feed it cassava flour and industrial flour. TRUST, GOVERNANCE, UPGRADING AND MARKET POWER 63

The Dutch Agricultural the existence of trust between cassava Trading Company Limited farmers and their buyers. The study also The Dutch Agricultural Trading revealed that all the agbelima processors Company Limited (DADTCO) was had a verbal agreement with their buyers established in 2012 as a processor before transactions came into effect. of cassava starch cake, which was However, the majority (78.3%) of gari supplied solely to Accra Brewery processors do not have any contract Limited for the production of cassava with their buyers, while, 21.7% had a beer. The Company had no cassava verbal type contract with their buyers. plantation and relied on individual The gari processors who had verbal cassava farmers who sold to them at contracts had them with wholesalers of the farm gate. By using a composite gari only. The study, however, revealed and modernized mobile processing that value chain actors involved in the technology, the company was able production of cassava starch, cake and to process raw cassava at any given high quality flour had written contracts location where cassava was available. with their buyers. This indicates a low A breach in contractual agreement trust relationship between these value between DADTCO and Accra Brewery chain actors and their buyers (Table Limited led to the collapse of the 4), but it guarantees an enforceable company in June 2015. contract with some legal implications. The details of the written contract The nature of trust, included procurement of cassava, governance, upgrading price of product, quality specification, i. Trust relations in the value chain delivery and payment schedule. Table 4 presents the results for the b. Length of trading relationship indicators of trust in the cassava value The study results revealed that the chain. mean length of a trading relationship a. Contracts of farmers with their buyer is about The study revealed that the majority of 12 years, while those of the gari and cassava farmers interviewed (85.7%) agbelima processors were about 11 had a contract with their buyers, while and 7 years, respectively. Using a 14.3% of the farmers did not have benchmark of 2 years to represent low contract with buyers (Table 4). The type trust relations, the findings suggest a of contract that farmers had with buyers high trust relationship in the cassava of cassava was verbal. This indicates 64 TRUST, GOVERNANCE, UPGRADING AND MARKET POWER

value chain. The study also revealed that produce is inspected upon delivery. For the mean trading relationship existing processors of cassava starch and cake between cassava starch, cake and high and high quality cassava flour, all of quality cassava flour processors’ and them indicated that their produce is their clients was about 5 years inspected upon delivery. The inspection (Table 4). of starch, cake and flour is on the colour, acid content, moisture content c. Ordering procedure and smoothness. Actors in the cassava value chain do not engage in open bidding, which, e. Degree of dependence according to Humphrey, Kaplinsky The cassava farmers, gari and agbelima and Saraph (1998), is an indication of processors sell their produce to high trust relations in the value chain. numerous buyers. There is therefore a Prices are negotiated along the chain. low level of dependence in the value However, this could be due to the chain actors and this indicates low trust absence of a commodity exchange in relations. However, producer of cassava Ghana, where open trading of cassava starch (Ayensu Starch Company) relies and its products could take place. solely on Guinness Ghana Limited. In addition, Guinness Ghana relies d. Inspection of produce solely on Ayensu Starch Company for About 79.10% of the farmers indicated the supply of cassava starch. This is that the buyer inspects their produce indicative of a high trust relationship. either on delivery or on the farm, while, In an event of a breach of contract, 20.9% indicated that there is little or no either party may be negatively affected. inspection of their produce (Table 4). Although Caltech Ventures depends on The majority of farmers indicating that Accra Brewery Limited, its diversified a form of inspection of produce before output allows it to sell to other value pick-ups, suggest low trust relationship. chain actors. Caltech Ventures Limited For agbelima and gari processors is therefore not over dependent on 83.30% and 81.70% indicated that their Accra Brewery Limited. TRUST, GOVERNANCE, UPGRADING AND MARKET POWER 65

Table 4: Trust relations in the cassava value Cassava starch Indicator of trust Farmers Agbelima Processor Gari Processor and high quality flour processors Yes=21.7% Yes=85.7% Yes=100% Yes=100% No=78.3% Contract No=14.3% Type=Written Type=Verbal (100%) Type=Verbal Type=Verbal (100%) (100%) (100%) Mean=6.53 Mean=5.00 Length of trading Mean=11.50 Mean=10.75 Std. Devia- Std. Devia- relationship Std. Deviation=5.74 Std. Deviation=7.95 tion=2.94 tion=3.37 Ordering No open bidding No open bidding No open bidding No open bidding procedure Prices negotiated Prices negotiated Prices negotiated Prices negotiated Produce inspected on delivery=65.10% Produce inspected Produce inspected Inspection of Inspection on on delivery=83.30% on delivery=81.7% Produce inspected produce field=14.0% Little or no Little or no on delivery=100% Little or no inspection=16.7% inspection=18.3% inspection=20.9% 1.Cassava starch processor has sole Processor supplies Farmer supplies to Processor supplies buyer and buyer to numerous Degree of numerous buyers, to numerous buyers, has sole supplier buyers, buyer dependence buyer has numerous buyer has numerous 2. High quality has numerous farmers suppliers cassava flour suppliers processors have few buyers Technical Yes=10% Yes=27% Yes=23% Yes=100% assistance No=90% No=73% No=77% Yes=10.3% Yes=3.3% Yes=23.3% Yes=75% Credit extended No=89.7% No=96.7% No=76.7% No=25% Frequent through Frequent through Frequent through Frequent through informal both formal and informal sources informal sources sources such as informal sources Communication such as mobile mobile phone, mobile phone, such mobile phone, face-face face-face face-face interac- phone, e-mails, interactions interactions tions letters Negotiated=95.7% Negotiated=93.3% Negotiated=80.0% Quoted by buy- Quoted by buy- Quoted by Bargained and Price er=4.0% er=5.0% buyer=16.7% agreement determination Quoted by sell- Quoted by sell- Quoted by reached= 100% er=0.3% er=1.7% seller=3.3% Payment delivery/spot=1.7% spot=38.3% spot=66.7% within 14 days duration within 14 within 14 within 14 after invoice=50% days=27.9% days=43.3% days=18.3% 3 Months after within 1 within 1 within 1 invoice=50% month=23.6% month=11.7% month=5% within 1 and half within 1 and half within 1 and half month=33.2% month=6.7% month=10% within 2 Months=1% within 3 Months=10% Part payment before delivery=2.7% Source: Field Survey, 2016 66 TRUST, GOVERNANCE, UPGRADING AND MARKET POWER

f. Technical Assistance g. Credit Extended Only 10% of the farmers receive Only 10.3% of farmers receive assistance from value chain actors on credit from value chain actors before new technological innovations. The production. The majority (89.7%) of type of support includes the supply farmers do not receive credit from of improved varieties extension and chain actors before production. Also, input support. The majority (90%) of 96.7% and 76.7% of agbelima and gari farmers do not receive assistance from processors do not receive credit from chain actors on new technology. This value chain actors before production. is indicative of low trust relations. This is indicative of low level of trust About 73% of agbelima processors do in the relationship between these actors not receive technical assistance, while and their buyers. However, the majority 27% receive technical assistance, an (75%) of cassava starch and cake, high indicative of low trust relationship. quality flour processors receive credit The technical support includes from their buyers, as indicative of the procurement and the use of modernize existence of trust. pressor, milling machines and new h. Communication processing technology. Majority of the The study results show that value gari processors (77%) do not receive chain actors such as farmers, gari and assistance on the use of new technology. agbelima processors communicate Only 23% receive assistance from the frequently with their buyers through use of new technology. The technical informal sources using mobile phones assistance received also includes access and face-face interactions. This is to cassava pressor, milling machines and indicative to high trust relations. In the use of alternative sources of energy addition, actors such as cassava starch such as gas stoves for processing the and cake, cassava flour producers gari. This is also indicative of a low trust communicate frequently with buyers relationship. All the cassava starch and from each stage of the production high-quality cassava flour processors process until the product is delivered. receive assistance on innovative These chain actors adopt multi- technology from their buyers and other channelled communication tools that chain actors. This is indicative of high are both formal and informal. It includes level of trust in their relationship. communication using mobile phones, face-to-face interactions, emails and TRUST, GOVERNANCE, UPGRADING AND MARKET POWER 67

letters. This is also an indication of high receive pre-finance before production. trust relationship. About 38.3% of agbelima processors i. Price determination are paid on the spot, while, 43.3% are It came out from the study that the paid within 14 days. This is indicative buyer and seller respectively imposed of lower trust relations compared to only 4% and 0.3% of prices received that of farmers. However, 66.7% of by farmers. The majority (95.7%) of the gari processors are paid on the spot, price received by farmers are negotiated while, 18.3% are paid within 14 with the value chain actor until an days. This is indicative of lower trust agreement is reached. This implies relations compared to that of agbelima there are fair trading practices and low processors. However, these different price exploitation in the value chain and levels of repayment time allowed could indicative of high trust relationship. also be related to the shelf life of the The study also revealed that 93.3% different products involved. Cassava of the price received by the agbelima starch and cake processors are paid 90 processor are negotiated, while, 80% of days after invoicing, while, high quality the prices received by the gari processor cassava flour processors are paid 14 are negotiated. This is indicative of days after invoicing, indicative of the high trust relations between the gari establishment of high trust relations. and agbelima processor and the buyer. ii. Governance in the cassava value Prices obtained by cassava starch and chains cake, high quality flour processors are The results from the study all negotiated until an agreement is suggest that the type of governance reached. existing between cassava farmers and their buyers is generally captive (Table j. Payment duration 5). This is because about 56.1% of Only 1.7% of the cassava farmers the farmers stated that the transaction interviewed were paid on the spot for process is complex. Transaction produce sold. About 85% of farmers between farmers and the buyer involves are paid between 14 days to 45 days farm visit(s) by buyer, agreement after sales of produce (Table 4). The on terms of payment, observing the long duration granted for repayment product mature, deciding the date to could be an indication of high trust harvest, harvesting and payments. relation within chain actor, other things Farmers interviewed indicated that being equal. About 2.7% of the farmers the high complexity of transaction is 68 TRUST, GOVERNANCE, UPGRADING AND MARKET POWER

because of the dispersed settlements, cost and poor roads. These factors have the inability to preserve the product, implications for the payment duration lack of a ready market, high transport allowed to buyers. Table 5: Type of governance in the cassava value chains

Cassava starch, cake Variable Farmers Agbelima Gari and high quality flour Complexity of Low=43.9% Low=54.2% Low=73.3% High=100% transaction High=56.1 High=45.5 High=26.7% Ability to Low=48.5% Low=43.9% Low=46.7% transmit High=100% High=51.5% High=56.1% High=53.3% information Capacity of Low=87.7% Low=47.5% Low=38.3% Low=25% chain actors High=12.3 High=52.5% High=61.7% High=75% Result of Captive Market Market Modular gover- governance governance governance governance nance type system structure structure

Source: Field Survey, 2016 In addition, it came out from the study captive governance structure between that 52% of the farmers interviewed are farmers and their client. The existence of able to transmit information efficiently a captive governance structure between with their buyers. This is done through the farmers and their buyers implies informal means using the mobile that the farmers could be exploited phones and face-to-face interactions. along the cassava value chain. Most cassava farmers also have low The study results also revealed capacity to meet the requirement of that the type of governance existing transaction. This was attributed among between agbelima processors and others to lack of funds (42.8%), poor their buyers is generally the market weather (18.5%), lack of market (6.8%), governance structure (Table 5). About traditional farming technique (7.2%), 54.2% of agbelima processors stated high input cost (6.2%) and low soil that the transaction process is simple. It fertility (6.4%). The high complexity entails the buyer coming to the market, of transaction, high ability to transmit a negotiation on price and agreement on information and low capacity to meet terms of payment. requirement of transaction imply a This process of transaction has been TRUST, GOVERNANCE, UPGRADING AND MARKET POWER 69

facilitated by their long relationship with their buyers, through informal with buyers and good knowledge ofthe means using mobile phones and face- price of product. About 56.1% of the to-face interactions. The majority of agbelima processors interviewed were gari processors (61.7%) are able to able to transmit information efficiently meet the requirement of transaction, with their buyers, done through which is attributable, among others, to informal means using the mobile phone the purchase of good quality cassava and face-to-face interactions. (42%) and low cassava prices (37.7%). The majority of Agbelima The presence of a low complexity of processors (52.5%) are able to meet transaction, high ability to transmit the requirement of transaction. This has information and high ability to meet been attributed, among others, to good requirement of transaction lead to a quality cassava (46.5%), low cassava market governance structure between prices (42.6%), increased volumes of gari processors and their buyers. cassava (9.3%) and experience (1.9%). The existence of market governance The presence of low complexity of structure between the gari processor transaction, high ability to transmit and its buyer implies there can be no information and high ability to meet exploitation. requirement of transaction lead to a On the other hand, the results market governance structure between from the study suggest that the type agbelima processors and their buyers. of governance existing between This implies that there can be no cassava starch, cake and high quality exploitation. flour processor and their buyers is It was also revealed from the generally the modular governance results of the study that the type of system (Table 5). This is because all the governance existing between gari actors encounter complex transaction processors and their buyers is generally with their buyers. The transaction the market type (Table 5). About process entails expression of interest, 73.3% of gari processors stated that presentation of sample, quality the transaction process is simple. It specification, sample tested, acceptance, involves the buyer coming to the market, pricing and supply agreements. All the negotiate on the price and an agreement processors of cassava starch, cake and on terms of payment. About 53.3% of flour are able to transmit information the gari processors interviewed are efficiently with their buyers. This is able to transmit information efficiently done through formal and informal 70 TRUST, GOVERNANCE, UPGRADING AND MARKET POWER

means using the mobile phones, face- a. Farmer to-face interactions, electronic mails The study showed that smallholder and letters. In addition, the majority farmers in the study area continue to (75%) of processors of cassava starch, use the traditional method of farming. cake and high quality flour are able to Major inputs used are cutlasses and meet the requirement of the transaction hoes. Large scale farmers, however, processes. This has been attributed, use agrochemicals and tractors in their among others, to recruitment of quality production process. On improvement staff, technological innovation and of product quality, 99.7% of farmers huge capital investment. The existence indicated that they have not improved of modular governance between the product quality, while, 0.3% have processors of cassava starch, cake improved on product quality. Few and high quality flour and their buyers farmers (47.5%) have moved to a imply there can be no exploitation. higher stage of the value chain, while, iii. Upgrading along the cassava 52.5% are stillon the same stage of value chain the value chain and not performing Table 6 presents the results for upgrading additional value addition. Additional of their cassava products and activities value addition by farmers in the chain by actors along the value chain. includes peeling the cassava (78.3%), peeling and cutting (1.4%). TRUST, GOVERNANCE, UPGRADING AND MARKET POWER 71

Table 6: Upgrading in the value chain

Cassava starch Upgrading Farmer Agbelima Gari and High quality flour

Yes=23.3% No=76.7% Yes Yes=26.7% 1. Use of pressor=58.8% 1.No upgrading by No=73.3% Continuous 2.Gas stoves=10% Smallholders Yes improvement 2.New knowledge=31.2% 2.100% process upgrading 1. Use of pressor=57.3% on production Process No through use of tractors 2.New knowledge=42.7% technology 1.Milled and agrochemicals by No Modern tech- 2. Stone pressing large-scale holders 1.Milled nology 3. Roasted using firewood 2. Stone pressing 4. Stirred using broken calabash 5. Packaged

Improvement No=99.7% in Ph, moisture, Product Nil Nil Yes=0.3% colour and smoothness

Yes=47.5% CS and HQCF No=52.5% performing Yes other functions Functional Peeling cassava=78.3% Nil Nil in the chain Peeling&cutting=1.4% like cassava Peeling&uprooting=1.4% cultivation Uprooting=18.9%

Production Inter-chain Nil Nil Nil of Co2 and Ethanol

Source: Field survey, 2016 b. Agbelima processor The majority (73.3%) of agbelima the value chain and not performing processors in the study area use the additional value addition. traditional processing technique. This c. Gari processor: includes stone pressing of the milled The majority (76.7%) of gari processors cassava. Only 26.7% of agbelima in the study area use traditional processors use modernized and improved processing techniques (Table 6). This technologies, like cassava pressor includes stone pressing of the milled (57.3%) and improved knowledge cassava. Only 23.3% of gari processors (42.7%). There is no improvement on use modernized and improved product quality and no innovations to technologies. These include use of improve product quality. Agbelima cassava pressor (58.8%), gas stoves processors are on the same stage of (10%) improved knowledge (31.2%). 72 TRUST, GOVERNANCE, UPGRADING AND MARKET POWER

There is no improvement on product is at the same stage of the value chain. quality and no innovations to improve 1.1.3 Extent of market power product quality. Gari processors are on (concentration) along the cassava the same stage of the value chain and not value chains performing additional value addition. Table 7 presents the estimated d. High-quality cassava flour Herfindahl-Hirschman Index (HHI), processor which measure the extent of market High-quality cassava flour processors power (or concentration) for the use modern and advanced processing different actor groups. The estimated techniques. There is product HHI shows that there is a high degree upgrading. Product upgrading is of fragmentation of cassava production through improvements on acid (pH) activities. Thus, the production of content, moisture content, colour and cassava is highly unconcentrated. The smoothness. There is also inter-chain estimated Herfindahl-Hirschman Index upgrading. This is because one high- (HHI) of 52.18 suggests that a farmer quality cassava flour processor has may not have the power to influence moved to a higher stage of the value price and quantity supplied to the chain and performing additional value market. Also, the low HHI estimates for addition such as the production of gari and agbelima processors suggest ethanol and carbon dioxide. Another that these actors may also not have the high quality cassava processor is also power to influence the price of gari and processing industrial flour and cassava agbelima. pressed cake (Table 6). However, the market for cassava e. Cassava starch processor: starch, cake and high quality flour Cassava starch processor also use is highly concentrated. The high advanced processing techniques (Table Herfindahl-Hirschman Index of 6). There is improvement on product 3987.73 suggests that a value chain quality. There is product upgrading actor in this market could influence the through improvements in pH, moisture price and quantity of the product. There content, colour and smoothness. There could be an abuse of market power by is no inter-chain upgrading and the actor the leading chain actors. TRUST, GOVERNANCE, UPGRADING AND MARKET POWER 73

Table 7: Degree of concentration

Market share (%) Herfindahl Level of concentration Chain actor Mean Std. dev -Hirschman Index of the cassava market Unconcentrated Farmer 0.33 0.2514 52.18 market Unconcentrated Gari processor 1.67 1.1698 247.40 market Agbelima Unconcentrated 1.67 0.6996 195.54 processor market Cassava starch and Highly concentrated 25.00 22.2691 3987.73 flour processor market Source: Estimated from field survey data, 2016

CONCLUSION AND most important market channel for RECOMMENDATION smallholder farmers. The market The study attempted to analyse the channels for large-scale producers and level of trust, governance structure, outgrowers include ethanol, cassava product upgrading and the extent of starch, industrial flour and high quality market concentration (power) of the flour processors. The presence of cassava value chain in Ghana, using vertical integration in the value chain data collected from sampled farmers, by the key participants engaged in both small and large scale processors along the processing of value-added activities the cassava value chain. Percentages and cultivation of cassava, is to secure were used to describe the level of the source of their raw material for trust, governance structure and processing activities. product upgrading and the Herfindahl- The results found that the levels Hirschman Index (HHI) was used to of trust relationship along the cassava measure the extent of market power value chain are mixed. While some (or concentration) in the cassava value of the indicators suggest high trust chains. relationships among actors along the The study found that there chain, others suggest otherwise. Among are about 21 market channels in the the various indicators of trust, the study cassava value chains in Ghana. Gari revealed that the majority of cassava and agbelima processing present the farmers and agbelima processors are 74 TRUST, GOVERNANCE, UPGRADING AND MARKET POWER

in a verbal contract with their buyers, The type of governance existing suggesting a high trust relationship. between cassava farmers and their Processors of high quality cassava flour, buyers is generally captive, which means cassava cake and cassava starch cake that other chain actors could exploit engage in written contracts with their farmers. On the other hand, the type of buyers. This is also an indication of a governance existing between gari and low trust relationship. The majority of agbelima processors and their buyers value chain actors have been in trading is generally the market governance relationship for more than two years structure. This implies that other actors and do not receive payment for their cannot exploit the gari and agbelima products on the spot. processors. The findings also suggest These are also indication of high that a modular governance structure trust relations. The majority (90%) of exists between the processors of cassava farmers do not receive assistance from starch, cake and high quality flour and chain actors on new technology. Only their buyers. This implies there can be about 10%, 27% and 23% of farmers, no exploitation by their buyers. There agbelima processors and gari processors, is low process and product upgrading respectively, receive assistance on new among smallholder farmers, while there technology, all indicative of low trust is high process upgrading by large- relationships. On the other hand, all scale producers. The study found out cassava starch and high quality flour that the majority of gari and agbelima processors receive assistance on new processors use traditional processing technology and this shows high trust techniques. However, there is product, relationship. All the actors along the process, functional and inter-chain cassava value chain communicate upgrading among high quality cassava frequently with their buyers through flour processors. The estimates of the formal and informal methods. These Herfindahl-Hirschman Index (HHI) for include the use of mobile phones, face- the cassava farmers, agbelima and gari to-face interactions and written letters. processors are low, showingactivities of This is indicative to high trust relations. these actors are highly defragmented. In addition, the study revealed that Its implication is that it is not possible prices are generally determined through for a cassava farmer, agbelima and negotiation. Very few chain actors gari processor to influence the price stated that the buyer or seller imposes of their respective products. However, prices on them. the estimate of the HHI for Cassava TRUST, GOVERNANCE, UPGRADING AND MARKET POWER 75

starch and high-quality cassava flour cassava-derived product value chains processors is very high, anindication for these chain actors. of a highly concentrated market, where Farmers, gari and agbelima lead actors can influence the price of the processors should be given technical product sold on this market. and credit support, which could be done The study recommends that the through integrating these chain actors policy to increase production should into a network of service providers. focus on improving the capacity of gari Through this, farmers, gari and agbelima and agbelima processors who represent processors will have access to credit a less concentrated segment of the value and improved technology. It is also chain and a major market for smallholder important to institute programmes to farmers. There is the need to modernize improve the capacity of farmers to meet smallholder cassava cultivation and the the business transaction requirements. processing of gari and agbelima through The producers of cassava starch should improved technology. The continuous diversify their product and client base use of traditional techniques does not for sustainable production. improve process upgrading in the 76 TRUST, GOVERNANCE, UPGRADING AND MARKET POWER

REFERENCES

Adjei-Nsiah, S., & Sakyi-Dawson, O. (2012). Promoting cassava as an industrial crop in Ghana: Effects on soil fertility and farming system sustainability. Applied and Environmental Soil Science. http://doi.org/10.1155/2012/940954 Adjekum, A. A. (2006). Cassava processing and marketing : experiences from Ghana. In Regional Initiative Workshop. Accra: IFAD. Atanasoaie, G. (2011). Distribution channels on the organic foods market. Journal of Horticulture, Forestry and Biotechnology, 15(3), 19–25. Bitran, G. R., Gurumurthi, S., & Sam, S. L. (2006). Emerging Trends in Supply Chain Governance. Working Report. MIT Sloan School of Management, Cambridge. Boehlje, M., & Bröring, S. (2011). The increasing multifunctionality of agricultural raw materials: three dilemmas for Innovation and Adoption. International Food and Agribusiness Management Review 14(2), 1–16. Bokanga, M. (1999). Cassava Post-harvest Operations. INPho-Post-harvest Compendium. FAO Bouckaert G., P. Laegreid and Van de Walle, S. (2005). Trust, quality measurement models and value chain monitoring. Journal of Chemical Information and Modeling, 53(9), 1689–1699. Caiazza, R., & Volpe, T. (2012). The global agro-food system from past to future. China- USA Business Review, 11(7), 919–929. Carbo-Valverde, S., Rodríguez-fernández, F., & Udell, G. F. (2006). Bank Market Power and SME Financing Constraints (pp. 1–45). Cervantes-Godoy, D., & Dewbre, J. (2010). Economic importance of agriculture for poverty reduction. OECD Food, Agriculture and Fisheries Working Papers. Retrieved from http://www.oecd.org/dataoecd/49/19/46341298.pdf Coulson, A. (Ed.). (1998). Trust and contracts: Relationships in local government, health and public services. Bristol: Policy Press, University of Bristol. Crespi, J. M., Saitone, T. L., & Sexton, R. J. (2012). Competition in U . S . farm product markets: Do long-run incentives trump short-run market power ? Applied Economic Perspective and Policy, 34(4), 669–695. http://doi.org/10.1093/aepp/ pps045 Dunn, E., & Villeda, L. (2005). Weaving Micro and Small Enterprises Into Global Value Chains: The Case of Guatemalan Textile Handicrafts. USAID. TRUST, GOVERNANCE, UPGRADING AND MARKET POWER 77

Frederick, S. (2014, Sept – Oct.). Combining the global value chain and global I-O approaches. Discussion Paper.International Conference on the Measurement of International Trade and Economic Globalization Aguascalientes, Mexico. Gereffi, G., Humphrey, J., & Sturgeon, T. (2005). The governance of global value chains. Review of International Political Economy, 12(1), 78–104. Ghana Statistical Service. (2013). Ghana living standards survey 6 with labour force module (GLSS6/LFS). Ghana Statistical Service (Vol. 86), Accra. Hammervoll, T. (2011). Governance of value creation in supply chain. Supply Chain Forum, 12, 116–126. Handfield, R. B., & Bechtel, C. (2002). The role of trust and relationship structure in improving supply chain responsiveness. Industrial Marketing Management, 31, 367–382. Humphrey, J. (2004). Upgrading in Global Value Chains (No. 28). Geneva. Humphrey, J., Kaplinsky, R., & Saraph, P. (1998). Corporate Restructuring: Crompton Greaves and the Challenges of Globalization. New Delhi: Sage Publication Limited. Humphrey, J., & Schmitz, H. (2000). Governance and Upgrading: Linking industrial clusters and Global Value Chain Research. IDS Working Paper (Vol. 120). Ji, C., Felipe, I. De, Briz, J., & Trienekens, J. H. (2012). An empirical study on governance structure choices in China ´ s Pork Supply Chain. International Food and Agribusiness Management Review, 15(2), 121–152. Kaplinsky, R., & Morris, M. (2000). A Handbook for Value Chain Research. Institute for Development Studies: Brighton, UK. Kariuki, J., Ochugboju, S., & Kottoh, M. (2013). The Hidden Potential of Cassava: The Future of West Africa’s Most Undervalued Crop. Retrieved from http:// acetforafrica.org/wp-content/uploads/2013/02/WAT_ISSUE_2_2013.pdf Kirimi, L., Sitko, N., Jayne, T.S., Karin, F., Muyanga, M., Sheahan, M., Flock, J. and Bor, G. A Farm Gate-to-Consumer Value Chain Analysis of Kenya’s Maize Marketing System. The Michigan State University (MSU) International Development Working Paper, No. 111. Kleih, U., Phillips, D., Wordey, M. T., & Komlaga, G. (2013). Cassava Market and Value Chain Analysis: Ghana Case Study. Final Report. Cassava: Adding Value for Africa. NRI (UK) and FRI (Ghana). Knipscheer, H., Ezedinma, C., Kormawa, P., Asumugha, G., Makinde, K., Okechukwu, R., & Dixon, A. (2007). Opportunities in the Industrial Cassava Market in Nigeria. International Institute for Tropical Agriculture. Kovács, N. (2011). Measuring Market Power Indirectly in the Insurance Market. Szecheni Istvan University. 78 TRUST, GOVERNANCE, UPGRADING AND MARKET POWER

Koyama, N., Kaiser, J., Ciugu, K., & Kabiru, J. (2015). Market Opportunities for Commercial Cassava in Ghana, Mozambique and Nigeria. Dalberg and IDH – The Sustainable Trade Initiative. Lee, Y. Y., Baldick, R., & Hur, J. (2011). Firm-based measurements of market power in transmission-constrained electricity markets. IEEE Transactions on Power Systems, 26(4), 1962–1970. http://doi.org/10.1109/TPWRS.2011.2157179 Leon, F. (2014). Measuring competition in banking: A critical review of methods. Etudes et Document Du Cerdi, 12. CERDI. Masuku, M.B., & Kirsten, J.F. (2003). The role of trust in the performance of supply chains : A dyad analysis of smallholder farmers and processing firms in the sugar industry in Swaziland. Contributed Paper Presented at the 41st Annual Conference of the Agricultural Economic Association of South Africa (AEASA), October 2-3, Pretoria, South Africa. Ministry of Food and Agriculture. (2007). Food and Agriculture Sector Development Policy. Accra. Mitchell, J., Coles, C., & Keane, J. (2009). Upgrading along value chains: Strategies for poverty reduction in Latin America. Briefing Paper. COPLA – Trade and Poverty in Latin America. Morrow, J. L., Hansen, M. H., & Pearson, A. W. (2004). The cognitive and affective antecedents of general trust within organizations. Journal of Managerial Issues, 16(1), 48–64. Musso, F. (2010). Innovation in marketing channels. Emerging Issues in Management, (1), 23–42. Naziri, D., Quaye, W., Siwoku, B., Wanlapatit, S., Viet Phu, T., & Bennett, B. (2014). The diversity of postharvest losses in cassava value chains in selected developing countries. Journal of Agriculture and Rural Development in the Tropics and Subtropics, 115(2), 111–123. http://doi.org/urn:nbn:de:hebis:34-2014121946902 Neven, D. (2014). Developing Sustainable Food Value Chains-Guiding Principles. Rome: Food and Agriculture Organization of the United Nations. Pietrobelli, C., & Rabellotti, R. (2004). Upgrading in clusters and value chains in latin america the role of policies. Sustainable Development Department Best Practices Series, 106. Retrieved from http://publications.iadb.org/bitstream/ handle/11319/5052/Upgrading in Clusters and Value Chains in Latin America. pdf?sequence=1 Porter, M. E. (2008). The five competitive forces that shape strategy. Harvard Business Review, (January), 78–94. Riedel, B., Bokelmann, W., & Canavari, M. (2009). Combining cluster and value chain approaches to analyze the competitiveness of fresh vegetables producers: Case TRUST, GOVERNANCE, UPGRADING AND MARKET POWER 79

studies in Germany, Italy and Spain. 113th Seminar of the EAAE “A Resilient European Food Industry and Food Chain in a Challenging World” – Chania, Greece, September 3-6, 2009. Retrieved from http://purl.umn.edu/58121 Saitone, T. L., Sexton, R. J., & Sexton, S. E. (2008). Market power in the corn sector : How does it affect the impacts of the ethanol subsidy ? Journal of Agricultural and Resource Economics, 33(2), 169 – 194. Sexton, R.J., & Zhang, M. (2001). An assessment of market power in the U.S. food industry and its impacts on consumers. Agribusiness, 17, 59-79. Shepherd, A. W. (2007). Approaches to linking producers to markets (No. 13). Agricultural Management, Marketing and Finance Occasional Paper. Rome. SRID. (2014). Agrictulture in Ghana : Facts and Figure. Accra, Ghana. Swinnen, J. F. M., & Vandeplas, A. (2009). Market power and rents in global supply chains. Agricultural Economics, 41(SUPPL. 1), 109–120. http://doi.org/10.1111/ j.1574-0862.2010.00493.x Swinnen, J. F. M., Vandeplas, A., & Maertens, M. (2007, Oct). Governance and surplus distribution in commodity value chains in Africa. Paper Prepared for Presentation at the 106th Seminar of the EAAE, Montpellier, France, 1–36. Szopa, P., & Pękała, W. (2012). Distribution channels and their roles in the enterprise. Polish Journal of Management Studies, 6, 143–150. Tirole, J. (2014). Market power and regulation. Royal Swedish Academy of Sciences, 50005(10), 1–54. Retrieved from http//kva.se Vieira, L. M., Paiva, E. L., Finger, A. B., & Teixeira, R. (2013). Trust and supplier- buyer relationships : An empirical analysis. Brazilian Administration Review, 10, 263–280. Webber, M. C., & Labaste, P. (2010). Building Competitiveness in Africa ’ s Agriculture. The World Bank. http://doi.org/10.1596/978-0-8213-7952-3 Webber, M., & Labaste, P. (2007). Using value chain approaches in agribusiness and agriculture in Sub-Saharan Africa: A methodological guide. Tools that make value chains work: Discussion and cases. Washington DC, World Bank. White, L. (2012). Market Power: How Does it Arise? How is it Measured?Stern School of Business Economics Working Papers. Retrieved from http://hdl.handle. net/2451/31547 Wu, C., Bose, S., Wierman, A., & Mohsenian-Rad, H. (2013). A unifying approach to assessing market power in deregulated electricity markets, 1–5. In Proc. of IEEE PES General Meeting, July. Vancouver, BC, Canada. Yaldiz, E., & Bazzana, F. (2010). The effect of market power on bank risk taking in Turkey. Financial Theory and Practice, 34(3), 297–314. 80

Overview of the Sweetpotato Value Chain in Ghana

Wie Prosper1, Robert Aidoo1, Ohene-Yankyera Kwasi1 and Arne Wangle2 1Department of Agricultural Economics, Agribusiness and Extension, Kwame Nkrumah University of science and technology (KNUST), Kumasi, Ghana 2National Food Institute, Technical University of Denmark (DTU), Denmark

Abstract at the processing node of the value This study was aimed at chain, limited working capital, limited examining the sweetpotato value chain access to credit and high perishability and constraints faced by actors along of produce are the most constraining the chain using Fanteakwa (Southern sector) and West Mamprusi (Northern factors. Policies and strategies aimed sector) districts as case study. Data was at improving the storability of the crop, elicited from 200 producers, 100 traders access to credit and information as and 80 processors who were drawn well as stronger coordination among through simple random, accidental actors in the chain are recommended and snowballing sampling techniques. to improve value chain visibility and Value chain mapping exercise revealed sustainability. that the sweetpotato value chain in Ghana is buyer-driven and governed INTRODUCTION largely by collectors who have capital One of the neglected (orphan) crops in advantage. However, the chain is the country is sweet potato. Like other characterized by weak coordination root and tuber crops, sweet potato is a among the key actors and high degree food security crop which contributes not of information asymetry. Producers are only to calorie intake but employment faced with high cost of chemical inputs, creation, income and poverty alleviation in production and distribution centers. poor road network to farms and high A number of farmers are involved in the cost of labour as constraints. Traders production of the crop in some Southern are constrained by high transport and Northern Regions of Ghana. Due cost, inadequate storage facilities and to its short gestation period, it can be high post-harvest losses. However, Overview of the Sweetpotato Value Chain in Ghana 81

cultivated three times in a calendar High perishability of the crop is also year by farmers serving as a constant seen as the main issue which has made and stable source of income for them. the development of the crop’s value The marketing and distribution as chain sluggish. The crop potentially well as processing of sweet potato can be cropped at least three times have generated employment to many yearly. However, heavy dependence households especially women, and on rains rather than irrigation has made livelihoods to such households largely the crop seasonal, reducing its cropping depend on the crop. potential. Also, limited utilization base Nutritionally, the crop is (few products currently made from the considered to be a well-balanced major crop) and knowledge in the processing plant food with a good ratio between of already existent products cannot be protein and calories, and has substantial gainsaid since the only known products amounts of vitamins, especially Vitamin from the crop are boiled, fried and roasted C, minerals, and trace elements. Due to forms with the fried form dominating its correct balance between protein and the local processing business. Limited calories, it is considered a good weaning coordination among actors in the value food for growing children (Berga et al., chain has made the value chain of sweet 1993). Whilst potentially the crop is potato less developed. recognized as being widely versatile in This paper addresses the following its uses, substantial risks and constraints research questions: of production and marketing have 1. Who are the major actors along caused the sector to remain relatively the sweet potato value chain in sluggish in terms of productivity and Ghana and what roles do they value chain development. play? Thiele et al. (2009) assert that 2. How is the sweet potato value significant issues confronting the chain in Ghana governed? sweet potato value chain are; Limited 3. What are the constraints faced access to quality planting materials and by actors along the sweet other production inputs due to the use potato value chain in Ghana? of vegetative method of propagation. METHODOLOGY There is also limited market for the crop The study was conducted in the as it competes with other prominent Fanteakwa and West Mamprusi districts root and tuber crops like yam which is of the Eastern and Northern regions of a much accepted alternative to the crop. 82 Overview of the Sweetpotato Value Chain in Ghana

Ghana respectively. They were selected to select four (4) communities from because of their prominence when it each district for selection of producers comes to the production of the sweet through balloting. Farmers in the potato. selected communities were then selected Data and sampling by way of simple random sampling Primary data formed the core of the approach using the village farmers’ list data used for this study. The data was from the AEAs and the random number obtained from farmers, processors and table was used to reduce selection marketers (traders) within the study biases significantly. Communities areas. The study used information on selected from the Fanteakwa district sweet potato production, sweet potato were Asadja, Asadja Proper, Akonta marketing, and constraints associated No. 2 and Asetey. With regards to the with activities along the chain. The West Mamprusi district, farmers were formal survey was preceded by an selected from Gabgini, Katabanawa, informal survey to obtain qualitative Nayoko and Tinguri. data on actors along the sweet potato Markets and communities used to value chain through Focus Group select traders and processors were Discussions (FGDs). Primary data purposively selected with areas of from the key actors were however high concentration given highest supplemented with secondary data from priority. A combination of accidental the District Agricultural Development and snowballing techniques were used Units (DADU) of the study areas. to select marketers/traders based on The population of the study was referrals from initial subjects. This all sweet potato farmers, processors approach was used due to the difficulty and traders in the Fanteakwa and West in getting a sampling frame at this level Mamprusi districts. A total of Three since initial survey conducted indicated Hundred and Eighty (380) respondents that traders had weak or non-existent were selected for the study comprising associations where such information Two Hundred (200) sweet potato could easily be acquired. Processors farmers, Eighty (80) processors and one were also selected using the accidental hundred (100) traders. With the aid of and snowballing sampling approach Agricultural Extension Agents (AEAs), since there are no official and formal a list of major production communities institutions where a list of the target was prepared, after which a simple (processors) could be obtained. With random sampling technique was used this, respondents were interviewed Overview of the Sweetpotato Value Chain in Ghana 83 as and when they were identified and Tables 1 and 2 present the sample willing to participate in the survey sizes for the traders and processors after which they referred enumerators drawn from various communities/ to other processors within that vicinity. markets. Table 1: Sample Distribution of Traders by Community/Market

District Community/Market Sample Size Agomanya 12 Ashongmang 10 Begoro 15 Fanteakwa Ehiamanhyene 13 Total 50 Katabanawa 10 Nayoko 13 Tinguri 12 West Mamprusi Walewale 15 Total 50 Source: Field survey, 2015. Table 2: Sample Distribution of Processors by Community District Community/Market Sample Size Ehiamanhyene 10 Fanteakwa Begoro 10 Agomenya 10 Ashongmang 10 Total 40 Katabanawa 10 Mamprusi West Nayoko 10 Tinguri 10 Walewale 10 Total 40 Source: Field survey, 2015. 84 Overview of the Sweetpotato Value Chain in Ghana

The preparatory phase of the study primary data regarding the general involved introductory visits to the nature of sweet potato production and District Agricultural Units where marketing since farmers also sold their discussions were held with the District produce. Enumerators were however Agric. Development Officers (D. D. dropped in groups at vantage market Os). Also, visits were made to research places and communities for them to institutions (i.e. CRI and SARI) to identify traders and processors in no find out available varieties of sweet systematic format given the delicate potato cultivated and the prominent nature and the difficult nature of getting areas of production. Through these these actors. Enumerators therefore consultations, areas for the study interviewed traders and processors who were identified. At the same time, were willing and ready to cooperate and discussions were held with market partake in the study. leaders in these areas to understand Method of Data Analysis sweet potato marketing activities in A combination of descriptive these markets. These visits contributed tremendously in the design of the statistics, value chain mapping and questionnaire,sampling strategy and simple narrations were employed to the subsequent administration of summarize the data collected from the questionnaires. The draft questionnaire sweet potato value chain actors. The was pretested in one community study employed frequency distribution (Asadja) and the Begoro market in the tables, proportions, arithmetic mean Fanteakwa district for the necessary and standard deviation to organize inputs to be made to make up a final and summarize the characteristics of complete structured questionnaire for the respondents as well as to identify the main survey. The final structured constraints faced by chain actors. The questionnaire was used to collect the value chain map was used to show the primary data needed for the study distribution channels for sweet potato through personal interviews. In and the interrelationships among the addition Focus Group Discussions actors in the chain. As an agricultural (FGDs) were also held in each commodity like sweet potato moves community particularly with farmers through various channels to the final with a minimum of five (5) farmers consumer, transactions take place participating. Focus group discussion among multiple chain actors, cost are guides were used as a tool for collecting incurred, money and information are Overview of the Sweetpotato Value Chain in Ghana 85

exchanged and value is progressively study revealed that, whereas there was added. To identify the key players in male dominance at the production stage, the chain and their interrelationships, there was female dominance at the a value chain map was generated from processing and marketing stages of the the field data. Mapping value chain sweet potato value chain. Actors along helps to get a better understanding the sweet potato value chain were in of connections between actors and the economically active age bracket of processes and interdependency between 30 and 50years. With regards to among actors and processes in a value the level of education, chain actors had chain. This exercise was carried out generally low level of education; they in qualitative and quantitative terms had attained basic level or never been through graphs, presenting the various to school. Majority (54%) of producers in the sweet potato value chain operated chain actors, their linkages and all the on their own farm lands and recorded operations of the chain from production an average output of 25 bags (109kg level through traders (collectors, per bag) from an average farm size of wholesalers and retailers) to processors 2 acres. With regards to membership of and finally to the consumer. an association, only 26% of producer, Findings 28% of traders and 11% of processors Demographic characteristics of belonged to associations. Value chain respondents actors were found to have limited Respondent characteristics have access to credit. Majority of chain been provided in Tables 3 to 5. The actors (>85%) financed their activities with their own funds. 86 Overview of the Sweetpotato Value Chain in Ghana

Table 3a: Socio-demographic characteristics of Producers Fanteakwa West Mamprusi (n=100) (n=100) All (N=200) Variables % % Freq. % Male 71 87 158 79 Sex Female 29 13 42 21 Never been to school 26 63 89 44.5 Basic 68 19 87 43.5 Educational Level Secondary 6 16 22 11 Tertiary 0 2 2 1 Single 14 7 21 10.5 Married 75 91 166 83 Marital Status Separated 2 0 2 1 Widowed 9 2 11 5.5 Own land 27 80 107 53.5

Land Family land 15 16 31 15.5 Tenure Arrangement Share cropping 53 0 53 26.5 Renting 5 4 9 4.5

Access to Yes 32 74 106 53 Extension No 68 26 94 47 Membership Yes 0 52 52 26 of a Co-operative No 100 48 148 74 Access Yes 14 17 31 15.5 to Credit No 86 83 169 84.5 Own funds 86 83 169 84.5 Friends/Relative 10 7 17 8.5 Source Financial of Funding institutions 3 10 13 6.5 Private money lenders 1 0 1 0.5 Source; Field survey, 2015 Majority (53%) of farmers in West Mamprusi due to the generally poor the Fanteakwa district practiced soil conditions in the sharecropping system due to the fact that of the country. It was realized from the they are farmers from Krobo land who study that majority (74%) of farmer in have come to settle in the Fanteakwa the West Mamprusi district compared district. There was considerable use of to their compatriots in the Fanteakwa fertilizer in the cultivation of the crop in district (32%) had access to extension Overview of the Sweetpotato Value Chain in Ghana 87

services. This was not very surprising agents in the West Mamprusi district since the study further revealed that is likely to be easier than those in the 52% of farmers in the West Mamprusi Fanteakwa since farmers could easily district were members of Farmer Based be organized under the supervision of Organizations (FBOs), a situation that FBO leaders in the former for training was almost absent in the Fanteakwa sessions to be offered to members in district. Information dissemination for groups than on individual basis. Table 3b: Socio-demographic characteristics of Producers

Fanteakwa (n=100) West Mamprusi Total (N=200) Variables (n=100) Mean Std. Dev. Mean Std. Dev. Mean Std. Dev. Age (years) 42.99 14.34 37.82 11.69 40.41 13.31 Years of schooling 7.48 2.62 9.1842 3.42 8.053 3.0054 Household size 5.8 2.91 8.28 4.6 7.04 4.032 Distance to 1.6 1.076 2.584 1.97 2.092 1.65 farm (km) Years of SP 14.36 9.17 6.6 5.45 10.48 8.47 farming Farm size 2.2825 1.77 1.2875 0.67 1.785 1.42 of SP (acres) Output 23.095 14.52 26.02 16.31 24.55 15.47 (109kg bag) Extension 2.1481 1.026 3.1067 1.58 2.8529 1.51 Contact Amount saved last 571.5556 469.029 241.1236 190.37 407.26 394.16 season (GHȼ) Credit received 576.42 517.32 286.47 75.74 417.41 374.89 last season (GHȼ) Price 93.7 12.28 65.88 11.0034 79.79 18.15 of SP (109kg) Income from 1899.8 1398.44 1274.82 645.84 1587.31 1130.74 SP (GHȼ) Profit for last 1310.9 1362.44 567.27 611.5 939.085 1117.33 season (GHȼ) Source; Field survey, 2015 Record keeping is very important of farmers in the Fanteakwa indicated for success in agriculture. However, they kept records as compared to about records keeping was seen to be on the 35% of farmers in the West Mamprusi low (41%) with the main reason being district. From the study, majority (84%) farmers’ inability to write. Only 6% of farmers indicated that their main 88 Overview of the Sweetpotato Value Chain in Ghana

source of funding was from their own account, majority (74%) of farmers savings from previous season’s sale of from the pooled sample had no bank farm produce.Farmers in the Fanteakwa account which was not surprising districts made an average income of GHȼ looking at the proportion of farmers who 1899.80 from sweetpotato sales during indicated their main source of funding the 2014 cropping season as against an as financial institutions. Most financial average income of GHȼ 1274.00 for institutions demand that farmers own farmers in the West Mamprusi district. account (with some level of savings) as With regards to ownership of a bank a requirement for financial assistance. Overview of the Sweetpotato Value Chain in Ghana 89

Table 4a: Demographic and socioeconomic characteristics of Traders

West Fanteakwa Total Mamprusi (N=50) (N=100) Variables (N=50) % % Freq % Male 4 0 2 2 Sex Female 96 100 98 98 <30 16 14 15 15 Age 30-60 80 76 78 78 >60 4 10 7 7 Retailers 40 26 33 33 Type of Trader Wholesalers 30 46 38 38 Collectors 30 28 29 29 Never Been to School 30 92 61 61 Educational Basic 68 8 38 38 Level Secondary 2 0 1 1 Tertiary 0 0 0 0 Fellow Traders 54 48 51 51 Target Processors 8 42 25 25 Customer Consumers 38 10 24 24 Main District Market 74 88 81 81 Main Point Market Within District 10 12 11 11 of Sale Market Outside District 16 0 8 8 Trade in Other Yes 52 44 48 48 Commodities No 48 56 52 52 Membership Yes 42 14 28 28 of a Trader Association No 58 86 72 72 Awareness of Yes 74 38 56 56 SP Price Information No 26 62 44 44 Source; Field Survey, 2015 90 Overview of the Sweetpotato Value Chain in Ghana

Table 4b: Demographic and socioeconomic characteristics of Traders

Fanteakwa (n=50) West Mamprusi (n=50) Total (N=100) Variables Mean Std. Dev. Mean Std. Dev. Mean Std. Dev. Age 42.12 10.63 42.5 12.57 42.31 11.58 Years of schooling 5.54 4.067 0.66 2.37 3.10 4.12 Household size 5.62 1.88 6.54 3.19 6.08 2.65 Total income 2336 1952.98 601 372.045 1468.50 1648.18 Distance 37.6795 80.58 4.525 2.19 20.044 57.28 Covered km Volumes of SP 12.945 13.89 4.16 2.61 8.55 10.88 handled per week Minimum capital 1676.2 1533.89 411.6 163.61 1043.90 1257.62 Requirement Entrance Fee 65 46.17 - - 65 46.17 Marketing cost 4188.74 4590.53 698.59 525.58 2443.66 3693.62 Unit Price 130.294 26.77 67.63 10.12 97.22 37.13 Total revenue 4937.56 5072.10 877.65 683.03 2907.60 4138.41 Profit (GHȼ) 748.82 982.021 179.06 190.35 463.94 759.75 Source; Field Survey, 2015 Table 5a: Demographic and socioeconomic characteristics of Processors Fanteakwa (n=40) West Mamprusi (n=40) Total (N=80) Variable Mean Std. Dev. Mean Std. Dev. Mean Std. Dev. Age (years) 38 6.51 34.40 7.67 36.2 7.30 Years of schooling 7.53 3.29 1.53 3.40 4.53 4.49 Household size 4.88 1.67 6.25 2.26 5.56 2.092 Average 3.91 4.59 2.77 1.26 3.32 3.33 distance (km) Total income f 1310.45 846.44 683.75 212.85 997.10 689.56 rom SP (GHȼ) Years of sweet 7.15 3.94 4.33 2.27 5.74 3.49 potato processing Unit Price/slice 0.2 0 0.10 0.016 0.15 0.050 of fried SP (GHȼ) Credit received for SP 1266.67 1342.63 - - 1266.67 1342.63 processing (GHȼ) Average processing cost 64.85 22.83 57.90 11.57 61.37 18.32 /cycle (GHȼ) Average 46.99 63.14 42.77 34.17 44.88 50.49 Profit/cycle (GHȼ) Source; Field Survey, 2015. Overview of the Sweetpotato Value Chain in Ghana 91

Table 5b: Demographic and socioeconomic characteristics of Processors

Fanteakwa West Mamprusi Total (N=80) (n=40) (n=40) Variables % % Freq % <30 7.5 22.5 12 15 Age 30-60 92.5 77.5 68 85 Never been to 12.5 80 37 46 Educational school Level Basic 83 17.5 40 50 Secondary 5 2.5 3 4 Processing more Yes 10 62.5 65 81 than one commodity No 0 37.5 15 19 Membership of Yes 0 22.5 9 11 Association No 100 77.5 48 89 Farm gate 10 10 8 10 Main Point of Collector 23 20 17 21 SP Procurement Wholesaler 30 15 18 23 Retailer 37 55 37 46 Spot trade 100 100 80 100 Mode of Contractual Marketing 0 0 0 0 arrangement Own equity 95 97.5 77 96 Main Capital Credit union 5 0 2 2.5 Source Susu Scheme 0 2.5 1 1.5 No savings 7 12.5 8 10 At home 45 72.5 47 58 Place of Savings Bank 28 0 11 14 Credit union 10 0 4 5 Susu scheme 10 15 10 13 Yes 15 0 6 7 Access to Credit No 85 100 74 93 Source; Field Survey, 2015 92 Overview of the Sweetpotato Value Chain in Ghana

Value Chain Analysis NGOs, Finanxial institutions and Value Chain Map of Sweet Potato Research Institutes. A two-way flow in Ghana of information occurs where service The value chain map of sweet potato providers receive feedback from in Ghana generated from the study producers and vice versa. Producers is depicted in Figure 1. The various after production of sweet potato have a actors in the value chain are depicted number of alternative channels through and the various distributional channels which they can sell their produce. It was of the flow of sweet potato to the final realized from the study that, majority consumer illustrated. From the map, it (65.5%) of producers sold their produce can be seen that producers mainly enjoy to collectors who mainly buy sweet support services such as input supply, potato from the farm gate with 30.5% financial assistance and extension of producers selling to wholesalers and educational programmes on innovative only 1.5% selling directly to retailers. technologies from service providers Less than 2% of producers sold directly such as MoFA, private input dealers, to processors and consumers. Figure 1: Value Chain Map for Sweet Potato in Ghana

2.0% 1.0% CONSUMERS 40.0% 60.0% 100.0%% 1.5% 2.0%% %%PROCESSORS

38.0% RETAILERS 60.0% WHOLESALERS % 20.0% 18.0% COLLECTORS 60.0% 30.5% 65.5% 1.5% PRODUCERS

SERVICE PROVIDERS [MoFA (AEAS), Private Input Dealers, NGOs, FIs, RIs]

Represents a two-way flow of information and technology Represents the physical flow of inputs and produce/products Source; Researchers’ own sketch based on Field data, 2015 Overview of the Sweetpotato Value Chain in Ghana 93

Majority (60%) of collectors sold their farm implements) essential at the produce to wholesalers, 20% sold to production stage. Sweet potato farmers processors and 18% sold to retailers. also participate in this stage of the value Only about 2% of collectors sold their chain particularly when it comes to sweet produce directly to final consumers. potato planting materials (vines) supply Wholesalers sold their produce to whilst training and actual multiplication retailers (60%) and processors (38%). of improved Sweet Potato vines was At the retailer level, however, 60% being facilitated by MoFA through its sold directly to sweet potato processors Agricultural Extension Agents (AEAs). and the remaining 40% sold to final Sweet potato producers are consumers. For processors, all of them the major actors who perform most (100%) sold their products directly to of the value chain functions right consumers in convenient and ready-to- from land preparation to farm inputs eat forms (roated or fried as chips). sourcing or procurement, through the primary production stage to post Value Chain Actors and their harvest handling and marketing. Some Roles notable post-harvest handling activities The Sweet Potato value chain map undertaken by producers include emphasizes the involvement of diverse sorting, grading, packing, storing, actors who participate directly or transportation, loading and unloading; indirectly in the value chain in Ghana. these are mostly done by the farmers The direct actors of a value chain are themselves if they send the produce those involved in actual activities along (sweet potato) to the market or traders the chain (input suppliers, producers, who go to the producing centers to buy traders, processors and consumers) at the farm gate. whilst the indirect actors can be said Traders in the value chain are to be actors who provide financial or those actors who basically ensure the non-financial support services, such as movement of the physical sweet potato credit agencies, government via MoFA, from the farm gate to processors or NGOs, , Researchers and final consumers. These actors are of extension agents (Kit et al., 2006). three types; collectors, wholesalers and Private input suppliers have been retailers. Collectors operate in assembly acknowledged by farmers as their markets and or farm gates to collect main source of input supply (especially sweet potato from farmers in village fertilizer, herbicides, pesticides and markets and from farms for the purpose 94 Overview of the Sweetpotato Value Chain in Ghana

of reselling to wholesalers and retailers. of sweet potato by processors are the They use their financial resources and wholesale and retail points. The main their local knowledge to bulk sweet activity performed at this stage includes potato from the surrounding area. They sorting of produce, peeling, washing, play an important role and they do know frying, boiling and packaging for sale to areas of surpluses well. Wholesalers consumers. This role is mainly tailored are involved in buying sweet potato at making the product convenient and mainly from collectors (and a few from ready-to-eat with the purpose of a producers) in larger volumes than any target market which is mostly location other actor and supply them to retailers, specific. processors and consumers. They also The provision of services such store produce, usually for a maximum as training and extension, information, of four (4) days. Wholesale markets are financial and research services are the main assembly centers for sweet the preserve of the supporting actors. potato produced in surrounding areas These supporting service providers from where collectors aggragate and in the sweet potato value chain are deliver the produce. They have better MoFA, private input dealers, NGOs, storage, transport and communication Financial Institutions and Research facilities than other traders. Institutions. Most of the training given Retailer involvement in the are at the producer level of the chain chain includes buying of sweet potato and these training programs are usually from wholesalers, transport to retail undertaken by MoFA through their points, grading, displaying and selling extension agents at the community to processors and final consumers. level. Such periodic training programs Retailers are the last trader link between focus on both pre – and post-harvest producers and consumers. They mostly activities and marketing. buy from wholesalers and sell to urban Governance of the Sweet processors and consumers. They are Potato Value Chain. The facilitation very key when it comes to the transfer role of value chain is performed of feedback information on consumer mainly by dominant actors. This is preferences.Processors are very vital done mainly through the movement in the value chain due to their role of the commodities and price setting in changing the physical form of the mechanisms. Generally, the governance produce whilst improving the shelf structure of the sweet potato value chain life of the crop. The points of purchase in Ghana is buyer-driven in nature. Overview of the Sweetpotato Value Chain in Ghana 95

The lead actors in the value chain are linking up with fellow collectors) are collectors and wholesalers. Markets at quite common in the chain, especially Walewale, Agomanya, Ehiamankyene during procurement and transportion and Achiaman are heavily dependent on of goods. Conflicts or disagreement collectors who determine the volumes between producers and traders are supplied and ultimately price. encounted periodically in major They set the mode of operation markets. Whilst farmers blame traders and rules of engagement in these for offering very low prices for their markets for other chain actors to follow. produce, traders also blame farmers Their market power is displayed amidst for not providing adequate produce a very high degree of informality in with the right quality specifications. the sweetpotato market where there Farmers are mainly smallholders and is very weak coordination. In most are not very organized when it comes instances, the relationship among to marketing of their produce. They the key actors is one of a free market are therefore price takers and hardly exchange which is not coordinated. As negotiate for improved prices. The a result of the poor information flow governance structure of the sweet and the high perishability of the crop potato value chain was observed to be (coupled with poor storage systems), similar across the two districts. primary producers have very minimal Constraints along the Sweet bargaining power. Potato Value Chain. The value chains The use of standard weighing of perishable and semi-perishable system for transaction and price commodities like sweet potato are determination is virtually absent. reported to be constrained by large post- Unstandardized bags (sacks) are used harvest losses and inefficient value chain for pricing with standard weighing management. These constraints are not scale. This exposes farmers to cheating, just at a particular level but along the given their weak bargaining position. entire value chain. The study therefore Vertical linkages among value chain sought to independently identify the actors is virtually non-existent due to various constraints faced by different the mistrust among the actors, and this actors along the sweet potato value has led to virtually no transaction based chain in Ghana.Producers identified on signed contractual arrangement. and agreed to a number of constraints However, horizontal linkages among presented to them after they were asked traders of the same type (i.e. collectors to rank the constraints based on a five 96 Overview of the Sweetpotato Value Chain in Ghana

point likert scale (1=strongly Agree ranking of the marketing constraints they and 5=Strongly Disagree). Table 6 face with a Kendall’s W value of 0.279 presents the key constraints faced at the which was significant at the 1% level. production node of the chain. Generally, Table 7 presents the major constraints high cost of chemical inputs, poor road encountered by traders in the sweet network, high cost of labour, limited potato value chain. From the study, it access to credit facilities and high was realized that high transportation labour requirement for the cultivation cost, inadequate storage facility, high of the crop were identified as the five post-harvest losses, poor road network most critical constraints that hinder the to produce source and limited capital effective production of sweet potato. were are the most pressing constraints Farmers were however indifferent hampering their role of traders along about access to land and chemical the value chain. The level of agreement inputs, unavailability of quality planting among the traders in their ranking of the material and inadequate storage constraints was weak (Kendall’s W = facilities as constraints. Although, 0.171) but significant at the 1% level. there was a weak agreement among Table 8 presents the constraints the various constraints identified with identified by processors along the sweet a Kendall’s W value of 0.107, this level potato value chain. Limited working of agreement was significant at the 1% capital for business, limited access level. With a Chronbach’s alpha value to credit, high perishability of raw of 0.677, the primary producers can be materials, poor storage facilities, high said to be about 67.7% consistent in processing cost and limited knowledge their ranking of the constraints. on new products were identified as Critical marketing constraints the most critical constraints facing identified by farmers were low processors in the value chain. There commodity price, poor road network was a 0.324 level of agreement among and long market distance. However, processors in their ranking of the farmers from the Fantekwa and West constraints as seen from the Kendall’s Mamprusi districts disagreed entirely W test which was significant at 1% that there was low demand for the level. The test of reliability and internal produce. The relative high demand may consistency conducted revealed that the be as a result of the low price offered constraints were internally consistent by traders for the produce. There was (Chronbach alpha= 0.569). agreement among the producers in their Overview of the Sweetpotato Value Chain in Ghana 97

Table 6: Constraints faced by Sweet Potato Producer Fanteakwa West Mamprusi Production Constraints* Pooled(N=200) (n=100) (n=100) High cost of chemical inputs 1.61 1.66 1.64 Poor road network 1.06 2.35 1.71 High cost of labour 1.59 1.89 1.74 Limited access to credit facilities 1.29 2.21 1.75 High labour requirement 1.78 1.98 1.88 High interest rate on credit 1.51 2.27 1.89 High incidence of pest and 2.3 1.59 1.95 diseases Erratic rainfall pattern 2.65 1.63 2.14 Poor/declining soil fertility 2.32 2.14 2.23 High cost of planting material 2.36 2.12 2.24 High weeds infestation 1.99 2.53 2.26 High level of losses 2.71 2.15 2.43 Limited access to extension services 1.71 3.2 2.46 Inadequate storage facilities 2.55 2.5 2.53 Unavailability of quality planting material 2.92 2.62 2.77 Limited access to chemical inputs 2.5 3.03 2.77 Limited access to land 2.64 3.6 3.12 Kendall’s W=0.107; Chi-square=341.171; df= 16; Sig. 0.000; Chronbach’s alpha = 0.677

Marketing Constraints Low commodity price 1.3 1.84 1.57 Poor road network 1.1 2.21 1.66 Long market distance 1.67 2.42 2.045 Inadequate storage facility 2.26 2.31 2.29 High transport cost 2.53 2.1 2.32 Poor linkage with value chain actors 2.66 2.28 2.47 Inadequate market information 2.04 3.12 2.58 High market toll 3.31 2.93 3.12 Low commodity demand 3.63 3.74 3.69 Kendall’s W=0.279; Chi-square=446.473; df=8; Sig. 0.000; Chronbach’s alpha = 0.484

* Ranking scale: 1=Strongly Agree; 2=Agree; 3=Neutral; 4=Disagree; 5=Strongly Disagree. Source; Field Survey, 2015 98 Overview of the Sweetpotato Value Chain in Ghana

Table 7: Constraints of Sweet Potato Traders Fanteakwa Pooled Constraints* West Mamprusi (n=50) (n=50) (N=100) High transport cost 1.62 1.64 1.63 Inadequate storage facility 2.32 1.8 2.06 High post-harvest losses 2.52 1.76 2.14 Poor road network to 1.94 2.38 2.16 produce source Limited working capital 2.02 2.38 2.20 Inadequate market 2.66 1.78 2.22 information Long market distances 2.36 2.14 2.25 High market toll/tax 2.42 2.24 2.33 Poor linkage with value 2.74 1.92 2.33 chain actors Low demand for 3.72 4.18 3.95 commodity Kendall’s W=0.171 ;Chi-square=154.13; df=8, Sig. 0.000; Chonbach’s alpha = 0.541 * Ranking scale: 1=Strongly Agree; 2=Agree; 3=Neutral; 4=Disagree; 5=Strongly Disagree. Source; Field Survey, 2015 Table 8: Constraints of Sweet Potato Processors Fanteakwa West Mamprusi Constraints* Pooled (N=80) (n=40) (n=40) Limited working capital 1.625 1.10 1.36 for business Limited access to credit 1.875 1.20 1.54 High perishability of 1.975 1.425 1.70 raw material Poor storage facilities of products 2.2 1.625 1.91 High processing cost 2.8 1.20 2.00 Poor road network to 2.875 2.025 2.45 produce source High transport cost 2.875 2.10 2.49 Low product price 2.2 2.95 2.58 Inadequate storage facility 3.1 2.825 2.96 High market toll/tax 2.8 3.40 3.10 Low demand for 3.75 3.45 3.60 processed product Kendall’s W=0.324 ;Chi-square=284.759 ; df=11; Sig. 0.000; Chronbach’s alpha = 0.569 * Ranking scale: 1=Strongly Agree; 2=Agree; 3=Neutral; 4=Disagree; 5=Strongly Disagree. Source; Field Survey, 2015 Overview of the Sweetpotato Value Chain in Ghana 99

Conclusion producers during negotiations since The study examined the sweetpotao delay in sales could lead to high levels value chain in terms of roles of actors, of post-harvest losses. The main actors governance structure and constraints providing support services to the core faced at every node of the chain. actors in the sweet potato value chain The study has revealed that fresh in Ghana are the Extension Unit of sweetpotatoes produced by farmers are the Ministry of Food and Agriculture taken through several intermediaries (MoFA), research institutes like SARI, (collectors, wholesalers, processors and and informal credit suppliers and rural retailers) with little value addition in banks. the form of cleaning, sorting, grading, Constraints identified to be most packaging, storage and transportation crucial to the production of sweet before reaching end-users who are potato were high cost of chemical largely located in urban centers. The inputs, poor road network to farms, intermediate buyers obtain sweet potato high cost of labour, and limited from farmers at about GHȼ80.00 per access to credit as well as high labour 109kg and sell same to consumers at requirement for production. At the a price of about GHȼ97.00 per 109kg. marketing/distribution node of the The main point of substantial value chain, high transport cost, inadequate addition occurs at the processor node of storage facilities, high post-harvest the chain where actual transformation losses, poor road network to producing of the produce from raw form into centers and limited capital for sweet sliced and fried forms takes place. potato trading are common constraints. The absence of contract arrangements, However, processors were faced with functional co-operatives and limited the constraints of limited working access to information is widespread in capital, limited access to credit, high the value chain leading to very weak level of losses and poor storability of coordination among key actors. As a processed products. consequence, the sweet potato value Improved access to credit is likely chain in Ghana is largely buyer-driven to strengthen the activities of actors along with traders virtually dictating price the value chain since limited capital was even though there is a semblance of a common constraint faced by actors negotiation with primary producers. at all nodes of the sweet potato value The highly perishable nature of sweet chain. Also, research efforts should be potato further weakens the position of geared towards improving the shelf life 100 Overview of the Sweetpotato Value Chain in Ghana

of the crop through improved storage in the sweetpotato value chain are likely techniques and development of shelf- to improve visibility, coordination and stable products from the fresh produce. functionality of the chain for improved Improvement in communication and livelihoods of all actors. introduction of contract arrangements Overview of the Sweetpotato Value Chain in Ghana 101

REFERENCES

Berga MVD, Boosman M, Cucco I, Cuna L, Jansson N, Moustier P, Prota L, Purcell T, Smith D, Wijk SV (1993). Making Value Chain Work Better for the Poor: A tool book for practitioners of value chain analysis. CIP (2000). Sweetpotato. Research and impacts, International Potato Center (CIP). Http://www.Cgiar.Org. Retrieved on 23/12/2010. CIP (2006). Food and Agricultural Organization (FAO) (2002). FAO Statistics.Food and Agriculture Organization, Rome, Italy [http:www.apps.fao.org]. Orodho, A. B., Alela, B. O., & J. W. Wanambacha (1995). Use of sweet potato (Ipomoea batatas L.) vines as starter feed and partial milk replacer for calves. KARIKakamega, Kenya. Thiele G., Lynam J., Lemaga B. and J. Low (2009). Challenge theme paper 4: Sweetpotato value chains. International Potato Centre (CIP): Lima, Peru. 102

Resource-Use-Efficiency in Yam Production in Pru District of the Brong Ahafo Region, Ghana

*Franklin N. Mabe and Dominic Tasila Konja Department of Agricultural and Resource Economics Faculty of Agribusiness and Communication Sciences University for Development Studies Nyankpala Campus, Tamale *Corresponding Author: [email protected]

ABSTRACT farming experience, household size The study analyses resource-use- and age of the farmer. It was deduced efficiency in yam production among a that with the exception of age of a randomly selected sample of 120 yam farmer, household size and experience producers in ten communities within in farming significantly affect the the Pru District in the Brong Ahafo allocation of farm size positively in region of Ghana. The Cobb-Douglass the study area. It was also revealed that production function (Double-log) household size and farm experience was used to estimate the coefficients significantly affect the allocation of of the various variables analyzed and yam seeds positively. The analysis marginal-value-product as well as again affirms that household size and marginal-factor-cost used to estimate farming experience significantly affect the efficiency of resource use in yam the allocative efficiency of quantity of production. The regression results labour employed in yam production. showed that, farm size, labour, yam In this regard, an improvement in the seeds and household size significantly allocative efficiency of farm size, yam affects yam output. The results of the seeds, agrochemicals and labour would resource use efficiency computation surely raise output of yam. The study indicated that farm size (4.094) and yam therefore recommends an effective seed (1.827) were being under-utilized farm level training programmes whilst labour (0.952) was over-utilized aimed at empowering rural farmers on in the study area. Various determinants effective allocation of inputs used for of input efficiency include; education, Resource-Use-Efficiency in Yam Production in Pru District 103

yam production. This could be done tuber group are made up of crops through the design and implementation with high percentage of carbohydrate of tailor made extension programmes and they are used for many purposes on efficient allocation of inputs for in the world. The term root and tuber improvement of yam productivity. refers to any growing crops which store edible materials in subterranean INTRODUCTION root, corm or tuber (Oke, 1990). They The contribution of agricultural consist of cassava, yam, cocoyam and sector to the overall development of sweet potato. Yam (Dioscorea spp) is Ghana cannot be underscored. Over second to cassava as the most important the year, the agricultural sector which tropical root crop and is among the most employs majority of the labour force widely consumed staple food crops in has contributed significantly to the the tropics and sub-tropics (Okigbo and Gross Domestic Product (GDP) of Ogbonnaya, 2006). Ghana. The sector is the key to overall It is an important tuber crop in economic growth and development of Ghana and contributes about 16% of the the country and it is expected to lead the country’s Agricultural Gross Domestic growth and structural transformation Product (GDP) (Anaadumba, 2013). of the economy [Ministry of Food According to Anaadumba (2013), even and Agriculture (MoFA), 2010]. The though Ghana is the third larger producer sector is dominated by small scale of yam, it is the leading exporter of yam farmers widely scattered in the rural globally. The world’s largest producer of areas [Ghana Statistical Service (GSS), yam is Nigeria followed Cote d’Ivoire. 2013]. Agricultural production in In 2010, the foreign exchange earnings Ghana comprises the cultivation of tree of yam placed it third position amongst crops, root and tubers, legumes, cereals the nontraditional export commodities and vegetables. Not only that but also, in Ghana (Lopez-Montes et al., 2012). the rearing of livestock and poultry as The importance of yam in Ghanaian diet well as fishing and aquaculture are part cannot be downplayed because Food of agricultural sector in Ghana. and Agricultural Organization Statistics All the above mentioned [(FAOSTAT), 2012)] recorded 300 kcal subsectors contribute significantly to as the per capita consumption of yam the overall development of Ghana. in Ghana thereby making yam the third Root and tuber crops are cultivated most important source of energy to the by smallholder farmers. The root and general populace. 104 Resource-Use-Efficiency in Yam Production in Pru District

Also, the importance of yam is The main target of most government seen in its output value (Asante et al., intervention in the yam subsector 2014). Yam is a highly valued traditional has been to help farmers appreciate crop. New yam festivals are celebrated the significant impact of improved among many rural folks in West African technologies to yam productivity. The sub region. Yam is used as dowry for actual average yield of yam in 2013 marriage ceremonies in Ghana and stood at 16.27Mt/Ha, a figure which other West African countries. Also, is less than half of the potential yield. the crop is a good source of industrial Seed yam production does not currently starch. Yam is a remarkable stable exist on a commercial scale in Ghana in improving food security situation [Millennium Development Authority and hence it is currently attracting (MiDA), 2010]. Therefore, there is a tremendous attention by national and problem with the ability of farmers to international organizations in the world. allocate the factor inputs efficiently. Despite the economic contribution Little research has been carried out to of yam in Ghana and West African find out how efficiently inputs are used sub-region at large, its production and it is therefore crucial to research is highly expensive considering the on the resource-use efficiencies of input requirements. Osei-Adu et al., yam production using Pru District of (2016) noted that considering the high the Brong Ahafo Region of Ghana as labour demands for land preparation, a case. planting, staking, weeding, harvesting Low yam yields are often and transport to market, yam is the most attributed to the use of poor quality expensive among root and tuber crops planting materials and other in Ghana. Farmers spend so much on the unimproved technologies. Producing planting materials (seed yam) due to the yam in large quantities requires the low multiplication rate of yams (Aidoo efficient use of inputs (land, labour, et al., 2011). The use of fertilizer for fertilisers, stakes, fungicides and other yam production in Ghana is on the low factors of production) (Nchinda et al., side. Generally, the inputs used in yam 2016). Considering the fact that farmers production are very traditional thereby are not able to obtain the potential affecting its productivity. productivity levels, it is therefore There have been several prudent for researchers to ask many interventions by the government which questions. The possibility of achieving aim at increasing yam productivity. the potential yield can be linked to Resource-Use-Efficiency in Yam Production in Pru District 105

resource use efficiency. Efficiency is at Concept of Production the heart of researchers in production Function and Efficiency economics. This is because the scope of The production function is a agricultural production can be expanded nominal relationship showing the and sustained by farmers through technical transformation of inputs into efficient use of resources, hence the outputs. Production is a neoclassical concentration on allocative/resource- theory which looks at how efficient use efficiency can help farmers increase factor inputs are used to generate yam productivity. output. It depicts efficient combinations This research aims to generate of inputs and outputs. A production useful information for the Ministry function specifies the maximum of Food and Agriculture, especially attainable output that a given set the Crops Directorate for policy of inputs can produce. The implicit directions. The study provided relationship between output and inputs quantitative evidence that identified is expressed as: Y = f (X , Ԑ ) [1] the main determinants of productivity i j i of small-scale yam farmers so that, Where Yi is the quantity of output for policies can be designed to improve th th i farmer, Xji is the quantity of j input upon the level of efficiency based on th for i farmer and Ԑi is the error term the information available. Moreover, for ith farmer. The production function donor organizations and aid agencies shown in equation [1] above takes the that are supporting Ghana’s agricultural four different functional forms namely diversification programme and also linear, exponential, double-log and working to improve the livelihood of semi – log. rural dwellers will gain a lot of insight The concept of efficiency, as from this study, especially in the move defined by Farrell (1957) can be grouped towards efficient usage of farm inputs. into three namely, technical, allocative The study also added knowledge to the and economic efficiencies. Technical existing scanty literature on resource- efficiency is defined as the capability to use efficiency among yam farmers in achieve a higher level of output given Ghana. comparable levels of inputs. Allocative efficiency which is also called resource- use efficiency deals with the extent to which farmers make efficient decisions 106 Resource-Use-Efficiency in Yam Production in Pru District

by using inputs up to the level at one needs to estimate and compare which their marginal contribution to marginal value productivities (MVPs) production value is equal to the factor for each resource with their respective costs. The combination of technical and acquisition cost (MFC). Resource-use- allocative efficiencies gives economic efficiency (RUE) of each of the factor efficiency. The chief aim of resource use inputs (Xi) is estimated by the ratio of efficiency is to find ways of increasing value of marginal product (VMP) to

output per unit of input and achieving marginal factor cost (MFC or Px). desirable inter-firm, intra-firm and Determinants of Resource-Use inter-sector transfer of production Efficiency in Yam Production resources in order to provide the means It has been noted that yam of achieving economic level of living. productivity is declining in most Allocative Efficiency refers to the producing areas in the Sub-region ability to produce at a given level of due to high cost of inputs, inadequate output using the cost-minimizing input technology as well as poor soil fertility. combination. Allocative efficiency This is not the case in Ghana as most is related to the ability of the firm to yam producers have adopted the use choose its inputs in a cost minimizing of fertilizer in the production of yam way. It reflects whether a technically thereby enjoying slight increase in efficient firm produces at the lowest yam productivity. In table 1, it is clear possible cost. In order to determine the that yam productivity has increased by economic efficiency of the resources 1.97% from 2014 to 2015 in Ghana. used in yam production, the Marginal The differences in yam productivity Value Product (MVP) of each resource may be connected to inefficiency were compared with its marginal factor in the allocation of farms inputs, cost (MFC) and the efficiency indicators technologies used as well as differences computed. in socioeconomic characteristics of Production function is used in yam farmers (Nwosu and Okoli, 2010). the computation of MVPs of each of the It is very evident in several studies resources (inputs) with its MFC. The that inappropriate inputs mix in yam marginal value product (MVP) of an production translates into the quantity input is the additional value of output of yam output harvested. In agricultural that can be produced by employing one production, resource-use efficiency is more unit of that input, ceteris paribus. very vital especially in yam production To estimate resource-use efficiency, Resource-Use-Efficiency in Yam Production in Pru District 107

where inputs account greatly to the total of useful goods (Bervidova, 2001). cost of production. Achieving increases in yam production For instance, Reuben et al. according to Degras (1993) requires (2012), in their study on resource-use increasing allocative efficiency of efficiency in yam production in Taraba labour, intensification of use of land and state, Nigeria, revealed that labour and expansion of indigenous technology. land were over utilized and under- Household roles in crop production utilized respectively. Also, according is not static but tend to be dynamic in to Ekunwe et al. (2006), in their study response to pressure from the changing on resource-use efficiency in yam social, cultural and economic setting production in Delta and Kogi state, (Agwu and Chukwu, 2006). It is sufficing Nigeria, showed that land, yam seeds to say that labour use efficiency in crop and labour were under-utilized in yam production depends on household production. It has also been affirmed characteristics, production inputs, type by Maikasuwa and Ala (2013) that of labour used and labour wage (Durno fertilizer, labour and land were under- and Stuart, 2005). Interestingly, Anyiro utilized by women in yam production et al. (2012) revealed in their study that in Bosso State, Nigeria. A study by labour wage, household size, gender, Maikasuwa and Ala (2013) reveals age, educational level and farm size that the reources (fertilizer, labour and of yam farmers significantly affect the farm size) were all underutilized by allocative efficiency of labour in yam women yam farmers in Bosso Local production. Government Area of Niger Stata=e in The allocation of farm size affects Nigeria. This phenomenon can be linked the quantity of other variable inputs to the inability of women to get access required in yam production which to farm resources such as farm credit manifests into the quantity of yam and land to expand their production harvested. According to MoFA (2016), activity. This implies that farm credit yam occupied about 430197.69Ha of and access to land determines resource- the agriculture land in Ghana in 2015. use efficiency in yam production. The aggregate increased of farm land Efficiency of labour use as a production for crops production is dependent on factor is expressed by the level of labour individual farmers’ socio-economic productivity. Labour productivity characteristics. is regarded as technical efficiency In spite of the fact that yam seed of human work utilized in creation is a critical input in yam production, 108 Resource-Use-Efficiency in Yam Production in Pru District

it also limits number of acreage and and Nkoranza. The district is along the productivity level in production. Over Volta Lake and it covers an estimated allocation of yam seed in production land area of 2,195 kilometers square. intensively affects output hence the The District shares boundaries with East requirement for an efficient allocation Gonja District to the North, Sene district to maximize yam output. Farmers in to the East, Nkoranza and Atebubu- Sub-Sahara Africa generally rely on Amanten Districts to the south and informal sources of seeds, which is Kintampo North and Kintampo South selected from their harvest, resulting Districts to the West. The vegetation of into lower quality and quantity of final the study District consists of grassland, product (ARD, 2008). To overcome this wooded Savannah and ‘fringe forest’ challenge in yam production, farmers and hence can be put into forest are advised to prevent the attack of pests savannah transition zone. The district and diseases on yam seeds and also adopt experiences two seasons in a year, the the Yam Minisett Technology (YMT) wet season and the dry season. The available to improve the productivity environmental, climatic and soil are level of yam. suitable for yam production. A total of 10 communities within METHODOLOGY the district were also randomly Study area, Sampling Technique and Data Collection selected for the study. Lastly, 10 to 15 farmers from each of the 10 selected Cross-sectional primary data was communities were randomly sampled obtained for this study. A multi-stage and interviewed. The random sampling sampling method was used in this study. was done in such a way that each The study was conducted in Brong district, community and farmer was Ahafo which is the second leading yam respectively given equal chance of producing region in Ghana. Out of being included in the study. This was eight major yam producing districts in done using balloting where names of the region, Pru District was randomly selected districts, communities and selected for the study. Pru District is farmers were randomly picked from located in the North-Eastern portion of the respective sample frame. A sample Sunyani, the regional capital of Brong size of 120 farmers was obtained for Ahafo Ghana. The district capital is the study. Primary data was obtained Yeji which is about 310km from the with the help of semi-structured regional capital, Sunyani via Techiman questionnaire. Resource-Use-Efficiency in Yam Production in Pru District 109

Data Analysis The limitation of this model is that it SPSS version 17 was used for data assumes constant returns to scale (Cobb entry, cleaning and validation. The and Douglas, 1928). Following the data was then copied into excel and originators, Cobb and Douglas (1928), imported into Eviews. The descriptive Cobb-Douglas production function is analysis was done using excel and specified as: SPSS whereas Eviews was used for =6 b e i econometric analysis. Frequency a [2] i = 0 å i e tables, bar charts and pie charts were =1 employed to describe the age, marital

status, gender and the educational level Where; Yi = output of yam (100medium

of respondents. size tubers), Xj = inputs. The Cobb- Empirical Model Specification Douglas production function shown in Empirical output model equation [2] can be linearized by taking the natural logarithms on both sides. This study employs Cobb-Douglas Therefore, the empirical model used production function due to its simplicity for the study was specified as: and appropriateness to the data analysed.

ln =b0 +b1 ln 1i +b 2 ln 2i +b3 ln 3i +b4 ln 4i +b5 ln 5i +b6 ln 6i +ei [3]

Where ln= Natural logarithm, X1 = quantity of agrochemical in litres, X2 =

quantity of yam seed in (100sets), X3 = quantity of labour in man-days, X4 = farm

size in hectares, X5 = age in years, X6 = household size, β1 – β4= are the respective

parameter estimates for conventional inputs and β5 and β6 are parameter estimates for unconventional inputs age and household size respectively. The parameter estimates are elasticities and they defined the percentage change in quantity of yam produced as a result of a 1% change in the respective inputs. They can be used to estimate respective input use efficiencies.

Estimation of Resource- The production function shows the use efficiency maximum amount of the output The objective of the producer is that can be produced using different to maximize profit either by increasing combinations of variable factor inputs. the quantity of yam (Y) produced or Note that the quantity of yam produced by reducing the cost of production. is in physical units (100medium tubers) 110 Resource-Use-Efficiency in Yam Production in Pru District

and hence Y is also referred to as the product (MVP) to marginal factor cost total physical product (TPP). The (MFC or P ). The use of this ratio X marginal physical product (MPP) of an is based on the assumption that the input is the additional output that can be farmers operated in purely competitive produced by employing one more unit input markets (Olukosi and Ogungbile, of that input, ceteri paribus. 1989). When a double log functional Resource-use-efficiency (RUE) form is differentiated, input elasticities

of each of the factor inputs (Xi) is are obtained as shown below. estimated by the ratio of marginal value

di

d ln i i b [4] = d = d ln i i

i

di æi ö =b ç ÷ [5] d i i è( )ø Where:

æ ö MVP = MPP ×P = b × i ×P [6] ç ÷ i è( i)ø

Pyi is the unit price of 100 medium tubers of yam (Y) The resource use efficiency (RUE) of input j used in yam production is defined as the ratio of the marginal value productivity (MVP) to the marginal factor cost (MFC). Mathematically, RUE is expressed as:

æb i ö P ç × ÷× i MVP RUE = = è( )ø [7] MFC MFC Resource-Use-Efficiency in Yam Production in Pru District 111

Note the marginal factor cost is the resource will improve yam productivity. respective price of the factor inputs at RUE > 1, the yam producers their arithmetic means. are also inefficient (under – utilizing The ratio has the following resources) in the production process. interpretation: For each resource used, More profit could still be made by if: employing additional input since each RUE =1, the yam producers are additional cost item incurred brings in efficient in the use of the particular more marginal revenue (MVP). resource. That is, the cost of producing From the resource use efficiency, the last additional item just equals the it is possible to determine the relative percentage change in MVP of each additional income derived from that input that is required for yam farmers to last item. allocate the particular input efficiently. RUE< 1, the yam producers are inefficient (over-utilizing resources) in %D =(1- RUE) * 100 [8] the production process. With this, the reduction in the rate of use of the Determinants of resource- recommendations, one needs to identify use efficiency the causes of the variations in allocative According to Onumah et al. efficiencies of the various inputs. The (2013), the estimation of efficiency of factors influencing allocative efficiency any production activities is necessary but of each of the inputs were identified it is not sufficient for researchers to make using simple average response model policy recommendations. Therefore, to as stated below. be able to make evidence-based policy

RUE i =d0 +d1 Ag i +d2 Edu i +d3S i +d4 Expi +h i [9]

Where Ag, Edu, HHS and Exp represents RESULTS AND DISCUSSIONS age (years), education (educated = 1 This section presents the socio- and 0 other wise), house size (numbers) economic characteristics of the study respectively. and their detail descriptions using percentages of respondent illustrated with the help of pie charts, bar chart figures and tables. It also gives 112 Resource-Use-Efficiency in Yam Production in Pru District

empirical estimates of resource-use of the respondents are aged from 30 efficiencies of each of the inputs and to 39 years. This represents about their determinants. 38.33% of the total of 120 yam farmers Socio-Economic Characteristics of interviewed. It was also revealed that, Respondents out of the 120 yam farmers interviewed, Socio-economic characteristics that 24.17% of them are aged from 21 to 29 would affect yam production and also years. These results reasonably imply explain the farming activities of the that yam farming in the study area are area were identified. The characteristics dominated by the youth. considered are gender, age, educational Also, the table indicates that level, marital status and farming majority of the farmers are males (97%) experience. with only 3% being females. Table 2 shows that majority Table 2: Age and sex of respondents

Variable Frequency Percentage Age 20 4 3.33 21 – 29 46 24.17 30 – 39 29 38.33 40 – 49 22 18.33 50 – 59 10 8.33 Above 60 9 7.50 Total 120 100.0 Sex Male 116 97 Female 4 3 Total 120 100.0 Source: Computation from field data (2015) Figure 1 also shows that high proportion whiles 17% were unmarried. Since (83%) of total respondents were married the majority of the respondents were Resource-Use-Efficiency in Yam Production in Pru District 113

married, it indicates the possibility of The educational level of yam farmers is availability of more family labour for known to affect their production. Figure yam production 2 reveals that majority (56%) of yam Figure 1. Marital status of respondents farmers in the study area have had formal education. The results indicate that 44% have no formal education, while 26%, 21%, 7% and 3% had primary, junior high, senior high and tertiary education respectively. These findings indicate high level of literacy among yam farmers in Pru District, Yeji. High literacy levels will enable farmers to understand the intricacies of factor and Source: Computation from field data product markets and also predispose (2015) them to adopt and use improved farm practices (Oluyole, 2005).

Figure 2. Marital status of respondents

Source: Computation from field data (2015) Figure 3 shows that, majority (37%) of the respondents had farm experience ranging from 11 to 20 years. About 19% of yam farmers have experience ranging from 21 to 30 years. This finding indicates that over 50% of the yam farmers interviewed had been involved in the production of the crop for more than 10 years. 114 Resource-Use-Efficiency in Yam Production in Pru District - 1.97 5.89 2.72 0.04 1.69 1.89 3.52 2.00 3.00 % Change in yield 0.00 0.00 5.46 7.83 2015 16.96 19.71 16.37 17.22 15.58 20.83 16.74 Yield (MT/Ha) Yield 0.00 0.00 5.35 7.61 16.63 18.62 15.94 17.21 15.32 20.45 16.17 2014 0.00 0.00 2015 2759.80 430197.7 31340.00 136568.0 140847.0 34474.89 40700.00 31028.00 12480.00 0.00 0.00 Area Cropped (Ha) 2014 2759.80 31340.00 34038.20 40262.00 30591.00 12480.00 428012.27 136131.27 140410.00 0.00 0.00 2015 15064.66 97774.66 7296123.0 617867.00 2235723.0 2425508.0 536959.32 847887.04 519339.40 (MT) 0.00 0.00 2014 Production Figures Figures Production 14769.27 94926.86 583515.10 521345.50 823191.30 494608.95 7118889.86 2169542.88 2416990.00 Ghana Upper West Upper Upper East Upper Northern Brong Ahafo Ashanti Eastern Volta Greater Accra Greater Central Regions Western Source: MoFA (2016). MoFA Source: Table 1: Comparison of 2014 and 2015 Regional Production Figures of Yam in Ghana of Yam Figures 1: Comparison of 2014 and 2015 Regional Production Table Resource-Use-Efficiency in Yam Production in Pru District 115

Figure 3. Farming experience of respondents

Source: Computation from field data (2015)

Factors Influencing Farm size, yam seeds and labour Yam Output show a positive relationship with yam The econometric equations were output whiles agrochemical, household estimated and the Cobb-Douglas size and age also give contrary signs to (Double-log) was used to analyze the a prior expectations (Table 3). The resource-use efficiency in yam result of the estimate showed that farm production. The explanatory variables size and yam seed used were statistically included in the production function significant at 1%, and household size are; quantity of agrochemical, quantity and labour employed were statistically of yam setts, farm size, and quantity of significant at 5%. This implies that these labour as well as age and experience. variables are the major contributors With the exception of agrochemical of the 62% (R-squared) variations in used and age, the coefficients of all the the dependent variable. Therefore, variables in the model were statistically a 1% change in farm size, yam seed significant indicating their individual and labour will result in a 0.224%, contributions as determinants of yam 0.452% and 0.155% increase in output production. The production function respectively. Also a percent change in also produces important statistical the household size will also result in a outcomes, for example, a measure of 0.185% reduction in yam output in the goodness of fit, R-squared (64%) and study area. least standard error of estimate value These findings are consistent with of 0.443 which are significant at Prob the results of studies by Awoniyi et al. > F=0.0000. (2006), Izekor and Olumese (2010) and 116 Resource-Use-Efficiency in Yam Production in Pru District

Shehu et al. (2010) in Ekiti, Edo and and farm size proved significant in yam Benue States in Nigeria respectively production. where quantity of yam seed, labour Table 3: Determinants of yam production (Double log model)

Variables Coefficient Standard Error P >value ln (Farm size) 0.2241*** 0.0859 0.011 ln (Yam seed) 0.4519*** 0.0667 0.000 ln (Agrochemical) -0.0884 0.0728 0.227 ln (Labour) 0.1548** 0.0861 0.075 ln (Household size ) -0.1848** 0.1055 0.083 ln (Age) 0.1738 0.1526 0.258 Constant 4.9419 0.6672 0.000 Number of obs. =100 Prob. > F =0.000 Root MSE= 0.4426 F( 6, 93)=25.59 R-squared = 0.6228 ***Significant at 1%, Significant at** 5%, Significant at* 10%. Source: Field survey (2015)

Resource-Use Efficiency and yam setts are 4.094 and 1.827 of Yam Production respectively suggesting they are under- Table 4 shows the estimates of utilized in the production of yam in the resource-use efficiencies for the study area. This result does not support various input variables; quantity the findings of Nwosu et al. (2014). of yam seed planted, farm This implies that, yam farmers in the size, agrochemicals and labour study area can only be allocatively employed. The results show that on average none of the farmers efficient if they increase the quantity were allocative efficient in the use of yam seeds planted and farm size. of any of the production resources Yam farmers can only get maximum (inputs). marginal value of farm size and yam It has been revealed that, quantity setts by respectively increasing the use of yam seed planted and farm size (land of these inputs by 309.4% and 82.7%. cultivated) were inefficiently allocated. Quantity of labour employed for The efficiency of farm size cultivated production was over-utilized because Resource-Use-Efficiency in Yam Production in Pru District 117

the calculated RUE index of labour labour in yam production in Nigeria. is 0.952 as shown in Table 4. This Meanwhile, labour under-utilization implies that the per unit cost incurred in their study contradicts the finding of by farmers in hiring labour is higher over-utilization in this study. than the marginal value that they get The marginal expenditure on from employing unit labour. Therefore, agrochemicals is higher than the farmers can only get optimum value marginal value that yam farmers obtain of labour by decreasing the amount from using the agrochemicals. This can of labour employed by 4.8%. In other be justified by the fact that the marginal words, yam farmers should decrease factor cost of agrochemical (Ghȼ11.39) the number of laborers used in their is greater than the marginal value of production to attain an optimum yield agrochemicals (Ghȼ7.08). From Table and be allocative efficient. 4, the estimated resource-use efficiency This finding agrees with Reuben of agrochemicals is 0.621 implying et al. (2012), who found out that labour over-utilization by farmers. and land were over utilized and under- There has been recent upsurge in utilized respectively in Taraba State, the use of pesticides in yam production Nigeria. According to Ekunwe et al. but this study suggests farmers need (2006), the resource-use efficiency to reduce the use of agrochemicals to index showed that there was under- enable them get maximum value. utilization of land, yam seeds and Table 4: Estimation of resource use efficiency in yam production

Variables βi MVPj MFCj RUE %Change Decision Rule in RUE Farm size 0.2241 45.769 11.983 4.094 -309.4 under-utilization Yam setts 0.4519 92.286 50.512 1.827 -82.7 under-utilization Agrochemicals -0.1848 7.0766 11.3875 0.621 37.9 Over-utilization Labour 0.1548 31.604 33.210 0.952 4.8 Over-utilization

Source: Field Survey (2015)

Determinants of Allocative farm size and labour. This shows how Efficiencies in Yam Production farmers allocate yam seeds, farm size Table 5 presents the determinants of and labour in respect of their, age, allocative efficiency of yam seeds, household size, educational level, and 118 Resource-Use-Efficiency in Yam Production in Pru District

experience in yam production. that, increase in household size and With the exception of education; farm experience by a unit will result all the other variables (household size, in a 0.466 and 0.464 increase in the age and farm experience) significantly allocative efficiency of farm size. Also affected the allocation of farm size. All an increase in the age of a farmer by these variables positively affected farm a unit will result in 0.289 reduction in size with the exception age which had farm size allocative efficiency. a negative relationship. This implies Table 5: Determinants of allocative efficiency of farm size in yam productions

Variables Farm size Yam setts Labour -0.2887** Age -0.0411 (0.0465) 3.2153 (2.9217) (0.1716) 0.4663*** 0.1072*** Household size 55.0319*** (2.0071) (0.1179) (0.0320)

Education 0.3374 (0.2484) 0.0918 (0.0673) 0.2741 (4.2283)

0.4636*** Experience 0.0675 (0.0418) -9.5139** (2.6261) (0.1543) 16.1603 Constant 32.6377 (1.1313) -170.4009 (71.0612) (4.1749) R-squared 0.2060 0.1398 0.8722 F-calculated (4, 115) 7.4600*** 4.6700*** 196.2*** ***Significant at 1%,** significant at 5% and values in parenthesis are standard errors Source: Field survey (2015) Table 5 shows that only household While household size depicts a size significantly affect the allocative positive relationship, farm experience efficiency of yam seeds positively. This shows a negative relationship with means that yam farmers will increase allocative efficiency of labour. The two the allocative efficiency of yam seeds variables are all significant at 1%. This by 0.107, if their household size means that yam farmers will increase increases by one person. Household their allocative efficiency of labour by size and farm experience significantly 55.03 if their household size increases affect the allocative efficiency of labour by one person. It also implies that employed in yam production. allocative efficiency of labour among Resource-Use-Efficiency in Yam Production in Pru District 119

yam farmers decreases by 9.514 when production. A yam farmer can increase their farm experience increases by one output depending on his or her socio- year. economic characteristics. Education and empowerment programmes with Summary and the help of extension officers and other recommendations private entities can help yam farmers to Majority of the yam farmers were be more efficient in the use of the scarce within the age range of 29-30 years with rsources at their disposal. high illiteracy rate. Yam seeds, farm In fact, some form of informal size, labour and household size were adult education will assist farmers to found to significantly affect output of be able to manage their farms well. yam. It was also found out that, yam It is recommended that yam farmers farmers under-utilized farm land and should increase the quantity of yam yam seeds but over-utilized labour seeds planted per acre and the farm in their yam production. Increasing size used whiles reducing the quantity the use of pesticides and fungicide of labour employed and the quantity would reduce yam rots and damage of agrochemicals used in order to be of yam tubers. The socio-economic allocatively efficient in production. The characteristics such as household size, government should also make subsidy age, experience and education had available on farm inputs at affordable high impact on the allocation of yam price to farmers. seed, labour and farm size in yam 120 Resource-Use-Efficiency in Yam Production in Pru District

REFERENCES

Aidoo, R., Nimoh, F., Bakang, J. A., Ohene-yankyera, K., Fialor, S. C., & Abaidoo, R. C. (2011). Economics of Small-Scale Seed Yam Production Implication for Commercialization. Journal of Sustainable Development in Africa. 13(7): 65–78. Agriculture and Rural Developemnet (ARD) (2008). Barrier, Catalyst or Distraction? Standards, Competitiveness and Africa’s Groundnut Exports to Europe. Luz B. Diaz Rios and Steven Jaffee. Agriculture and Rural Development Discussion Paper 39, World Bank. Agwu, A. E. and Chukwu, P. C. (2006). Household roles and constraints in yam Cropping systems in Anini Local Government Area of Enugu State, Nigeria. International Journal of Agriculture and Rural Development. 7 (1). Anaadumba, P. (2013). Analysis of incentives and disincentives for yam in Ghana. Technical notes series, MAFAP, FAO, Rome. Anyiro, C. D., Emerole, C. K., Udah, S. C. and Ugorji, S. E. (2012). Labour-use efficiency by smallholder yam farmers in Abia State, Nigeria. International Journal of Food and Agricultural Economics. 1 (1): 151-163. Asante, B. O., Villano, R. A. and Battese, G. E. (2014). The effect of the adoption of yam minisett technology on the technical efficiency of yam farmers in the forest- savanna transition zone of Ghana. African Journal of Agricultural and Resource Economics. 9 (2): 75-90 Awoniyi, O. A. and Omonona, B. T. (2006). Production efficiency in yam-based enterprises in Ekiti State, Nigeria. J of Central European Agric. 7(4): 627-636. Bervidova, L. (2001). Labour productivity as a factor of sustainable economic development of the CR agriculture. The Agric. Econ. 48(2): 55-59. Cobb, C. W. and Douglas, P. H. (1928). A theory of Production. America Economic Review. 18: 139-165. Degras, L. (1993). Different behaviours of cultivars Dioscorea alata and Dioscorea prifida cultivated. In vitro Proc. of Caribbean regional workshop on tropical root Jamaica: Dolly. Ekunwe, P. A., Orewa, S. I. and Emokaro, C. O. (2006). Resource use Efficiency in Yam Production in Delta and Kogi State of Nigeria. Asian J. Agric. Res. 2(20):61-69. Farrell, M. J. (1957). The measurement of productive efficiency. Journal of the Royal Statistical Society. Series A. General. 120 (3), 253–290. Resource-Use-Efficiency in Yam Production in Pru District 121

Food and Agricultural Organization Statistics (FAOSTAT) (2012). FAO database. Rome: FAO. Ghana Statistical Service (GSS). (2013). Final 2012 Gross Domestic Product & Revised 2013 Gross Domestic Product. International Institute of Tropical Agriculture (IITA) and EIARD (2013). Healthy yam seed production. International Institute for Tropical Agriculture (IITA) (2009). http.//www.iita.org. Accessed July 21, 2016. Izekor, O. B. and Olumese, M. I. (2010). Determinants of yam production and profitability in Edo State, Nigeria. Africa J of Gen Agric. 6(4): 205-210. Lopez-Montes, A., Manson, H., Lascari, R., Sikpa, T. and Kodwo, N. (2012). Yam Sector Development Strategy, Ghana. Maikasuwa, M. A. and Ala, A. L. (2013). Determinants of profitability and resource-use efficiency of yam production by women in Bosso Local Government Area of Niger State, Nigeria. European Scientific Journal. 9 (16): 198-205 Millennium Development Authority (MiDA). (2010): Investment Opportunity in Ghana; Rice and Soyabeans, Millennium Development Authority, Accra, Ghana. MoFA (2010). Medium Term Agriculture Sector Investment Plan (METASIP), Ministry of Food and Agriculture (MoFA), Accra, Ghana. MoFA (2016). Statistics, Research and Information Directorate (SRID), Min. of Food & Agric. – March, 2016 Nchinda, V. P., Villano, A. R. and Morales, L. E. (2016). Performance of smallholder minisett seed yam farm enterprises in Cameroon. African Journal of Agricultural and Resource Economics. 11(4) 277-291 Nwosu, C. S., Chidebelu, S. A. N. D. (2014). Resource Productivity under Yam Based Crop Mixture in Crude and Non-Crude Oil Producing Communities of Imo State, Nigeria. Agricultura Tropica Et Subtropica, DOI: 10.2478/ats-2014-0003. 47(1), 20-28, Norman, M. J. T., Pearson, C. J. and Searle, P. G. E. (1995). Tropical Food Crops in their environment 2nd Edition. Cambridge University. press, U.K. pp. 305 – 316. Oke, O. L. (1990). Roots Tubers Plantain and Bananas in Human Nutrition, FAO Food and Nutrition Series No. 24. Okigbo, R. N. and Ogbonnaya, U. O. (2006). Antifungal effects of two tropical plant extracts (Ocimum gratissimum and Aframomum melegueta) on post-harvest yam rot. African Journal of Biotechnology. 5(9). 727-731. Olukosi, J. O. and Ogungbile, A, O. (1989). Introduction to Agric. Production Economics: Principles and Applications. 1st Edition. Zaria, Nigeria: AGITAB Publishers. 122 Resource-Use-Efficiency in Yam Production in Pru District

Oluyole, K. A. (2005). Evaluation of the Economics of Post-Harvesting Processing of Cocoa in Cross River State, Nigeria. Journal of Agriculture, Forestry and the Social Sciences. 3(2): 58-64. Onumah, J. A., Onumah, E. E., Alhassan, R. M. and Brümmer, B. (2013). Meta-frontier analysis of organic and conventional cocoa production in Ghana, Agric. Econ. Czech. 59(6): 271–280. Osei-Adu, J., Acheampong, P. P., Amengor, E. N. and Sagoe, R. (2016). Input Supply Structure for Yam Production in Ghana. Journal of Economics and Sustainable Development. 7(2): 72-78. Reuben, J. and Barau, A. D., (2012): Resource Use Efficiency in Yam Production in Taraba State, Nigeria, J Agri Sci. 3(2). 71-77. Shehu, J. F., Iyortyer, I. T., Mshelia, S. I. and Jongur, A. A. U. (2010). Determinants of yam production and technical efficiency. J Soc Sci. 24(2): 143-148 123

Consumers’ Perception and Willingness to Pay for Cassava-Sweet Potato Non-Alcoholic Beverage (Bansu) in the Kumasi Metropolis

Aidoo Robert; James O. Mensah; Opoku Ware, Emmanuel; Gademor, Doe Donatus; Osei, Awura-Abena Amoah; and Ntim, Caleb Department of Agric. Economics, Agribusiness & Extension, KNUST- Kumasi

Abstract consumer will purchase the product. In This research work assessed general, consumers of non-alcoholic consumers’ perception and willingness beverages in Kumasi have positive to pay for cassava-sweet potato non- perception about Bansu and majority alcoholic beverage (Bansu). Three (59%) are willing to pay at least GH₵2.20 hundred (300) consumers were selected for 350ml of the product when it is from the Kumasi Metropolis using a made available on the market. Contrary two-stage sampling technique. A three to a priori expectations, consumers in – point rating scale was employed to high income communities and younger examine product attributes that inform people were found to be more willing to the decision of consumers to purchase pay for Bansu, all things being equal. In Bansu. Perception index was also used addition to promotion and sensitization to evaluate consumers’ perception among the consuming public, proper regarding the qualities of Bansu. The packaging, FDA certification and double-bounded dichotomous choice labelling are recommended for a smooth Contingent Valuation Method (CVM) introduction of the product (Bansu) and Tobit regression model were onto the Ghanaian food market. employed to examine consumers’ Willingness to Pay (WTP) for Bansu BACKGROUND and its determinants. Among several A ‘soft’ drink is a drink that typically product attributes of Bansu, nutritional contains carbonated water, a sweetener, benefit and certification by Food and and a natural or artificial flavoring. Drugs Authority (FDA) were the The sweetener may be sugar, high- most important consideration before a fructose corn syrup, fruit juice, sugar 124 Consumers’ Perception and Willingness

substitutes, or some combination of connection to the obesity epidemic is these. Soft drinks are convenient and so well-known. Harvard researchers readily available for consumers to have calculated each additional soda quench their thirst and hunger when consumed increases the risk of obesity they are very busy to go for full meal. 1.6 times (Institute of Medicine, 2012). If used in moderation, soft drinks can People who drink sugary beverages do have beneficial health effects. This is not feel as full as if they have eaten because; they provide energy, minerals the same calories from solid food, and and some vitamins. Carbonated water, studies show that people consuming a component of most soft drinks, eases sugary beverages do not compensate stomach aches, quells nausea and has for their high caloric content by eating been proven to alleviate constipation less food. (Cuomo et. al., 2002). Soft drinks In view of the above, efforts with reasonable amount of caffeine are being made to reduce consumers’ stimulate the central nervous system, preference for sugary beverages in many help breakdown fatty acids in the liver, countries. Beverage manufacturers can boost consumer’s mood and alleviate make it easier for everyone to drink headaches (Nawrot et al., 2013). more healthfully by creating beverages Sodium, another product found in soft that have less sugar and little or no drinks, helps avoid and treat muscle carbonated water. In this regards, the cramps, keeps electrolyte balance, Danida root and tuber value chain prevents the effects of aging of skin and project has developed a soft drink from prevents a drop of blood pressure. It is cassava and sweet potato called Bansu also an essential nutrient necessary for which has these desirable attributes. maintenance of plasma volume, acid– Bansu has low sugar, no sweetener, and base balance, transmission of nerve no carbonated water (Wireko-Manu et impulses and normal cell function al., 2016). (WHO, 2012). Preparation of Cassava- Regardless of these benefits that Sweetpotato Non-Alcoholic Beverage soft drinks may deliver, the health risk (Bansu) In Preparing of Cassava-Sweet associated with their consumption potato drink, Cassava and Sweet potato is high. Rising consumption of soft (SP) roots were weighed, washed, knife drinks has been a major contributor peeled and washed again. The peeled to the obesity epidemic, diabetes, cassava roots were soaked in water gout and heart diseases. Soft drinks’ (1 kg: 3.5 L) for 2 hours to reduce Consumers’ Perception and Willingness 125

cyanogenic compounds while the SP (1 whether they would be willing to pay kg) was soaked in 2% lemon solution for it when it is made available on the (40 ml lemon juice: 2 L water) for 5 min market. to control browning. The roots were The purpose of this study was grated separately and homogenized therefore, to examine consumers’ together (1 kg composite root per 1 perception about the product (Bansu) L water). Using a cheese cloth, the and their willingness to pay for it. roots extract was obtained through FACTORS INFLUENCING squeezing. Additional 1 L of water was CONSUMERS’ added to achieve more extraction. Five WILLINGNESS TO PAY percent (5%) maize malt was added to FOR FOOD PRODUCTS the juice as source of external β – and Many factors have been anticipated α-amylase enzymes to convert starch to influence consumers’ or people’s to sugars. Sugar 11% (w/v) and 100 willingness to pay for food products. ml of 25% (w/v) ginger were added These factors include price of products, and heated to a temperature of 67 °C the level of consumers’ awareness, (optimum temperature for amylase) consumer’s purchasing characteristics, and maintained at that temperature perception, knowledge of product, for 20 min using a water bath (Buchi, consumer’s demographics such as age, B-480, Germany). The temperature sex, level of education, income level, was then raised to 70 °C and maintained occupation, marital status, household for 10 min to pasteurize the beverage. size as well as the characteristics of The mixture was strained with a 2-layer the product such as the taste, nutrition cheesecloth, allowed to stand for 15 min and health (Chen and Chern, 2002; Liu and decanted. This step was repeated to et al., 2009). According to Pouratashi reduce settling of the juice particles. The (2012), attitude, knowledge, age, drinks were bottled hot and stored in a income, characteristics of agricultural refrigerator. One kilogram of raw roots products such as tastes, colour, and produced 1.8L of cassava-sweet potato nutritive value were among the factors drink (Wireko-Manu et al., 2016). influencing willingness to pay for a Since consumers have general product. This is similar to the findings negative perception about cassava and of Fathelrahman et al. (2015) who some products made from the crop estimated socio-economic factors (Oyimbo, 2013), it is not clear how they such age, education, income, gender, will perceive the beverage (Bansu) and 126 Consumers’ Perception and Willingness

household size to have an influence on demand will rather decrease as one’s consumers’ WTP for food products. income increases since consumers Different studies have been generally have a negative perception carried out on consumers’ willingness about cassava and some of its related to pay for various food commodities. products as being a poor man’s food For instance, Jerop et al. (2014) (Oyimbo, 2013). Also, educational analyzed consumer’s willingness to level having a positive influence on pay for dairy goat milk in Kenya by consumers’ willingness to pay can also using double bounded dichotomous be attributed to the fact that educated choice contingent valuation model. consumers have more concern about Estimates from the logit reveal that, age, their health and also have higher education, household size, awareness incomes and as such are more likely and gender significantly exerted effects to pay for healthy and nutritious on consumer’s willingness to pay for food products like Potagurt. Hence, dairy goat milk in Kenya. consumers’ level of education is also Adu et al. (2015) analyzed likely to have significant positive consumers’ willingness to pay a influence on consumers’ willingness premium for sweet potato yoghurt to pay for Bansu since it is regarded as (potagurt) using the Tobit regression nutritious and healthy (Wireko-Manu model and the contingent valuation et al., 2016). However, with the higher method. Results from their study income levels of educated consumers, it revealed monthly income, training can also be the other way around. graduates, university graduates, Mostly WTP estimates are perception about the mineral content of negatively influenced by age Potagurt, perception about healthiness (Dolgopolova, 2016). However, Liu of Potagurt and perception about sugar et al., (2009) in their research work level of Potagurt had significant positive established that willingness to pay effects on consumers’ willingness to increases as one’s age increases. This pay a premium for Potagurt. Consumers is a clear cut contradiction and maybe demand for fashionable foods are likely attributed to methodological issues, to increase as their income increases. for example, elicitation method, as This could be the reason why they had well as to factual differences such as such result in their study. With Bansu, for example heterogeneous consumer which is coming from cassava as one preferences in different regions of of the main ingredients, it is likely that the world (Dannenberg, 2009; Lusk Consumers’ Perception and Willingness 127

et al., 2005). Age can be expected to Oviahon et al. (2011) conducted a have a negative influence on locally study on the determinants of consumers’ manufactured food products like Bansu willingness to pay for safety labels. since the youth of today have taste and Their regression results revealed that preference for fashionable and foreign educational level, new price, marital things. Also, a study conducted by status, and source of information were Fang (2015) on evaluating consumer the variables significant in explaining response to labels and packaging in consumers’ willingness to pay. Angulo the market for baby foods, found out et al., (2003) stated that, use of food that age of mothers has a significant labels, prices consumers actually pay negative effect on the labeled baby food. and the experience with the product Income and education have a significant were the factors that had a significant positive impact on consumers’ effect on willingness to pay for organic purchase of labeled baby food and also foods. Williams et al. (2000) found marital status and number of children that age and gender are significant have no significant effect on labeled determinants of WTP for food safety. baby food purchases. Munene (2006) However, Darby et al. (2006), and analyzed consumers’ attitudes and Barreiro et al. (2005) did not find any their willingness to pay for functional significant association between age of foods using ordered probit models and consumers and their willingness to pay the Contingent Valuation Method. He for a product in a hypothetical market. found that beliefs about the relationship Florax and Nijkamp (2005) between nutrition and health, current employed a meta-regression framework purchasing and consumption patterns, in their analysis. The result from their concern about chronic diseases, study indicated that geographical and attitude towards functional location, sampling type and safety foods were factors that significantly enhancing measure type significantly affected consumers’ willingness to influence willingness to pay estimates. pay a premium for functional foods. Socio-demographic characteristics such Also, a study conducted by Pasquale as; age, sex, income and educational et al., (2011) on consumer attitudes level were found to be connected with and willingness to pay for functional WTP estimates (Teratanavat & Hooker, foods, found out that, factors such as 2005; Nordström, 2012; Hellyer et al., knowledge of functional foods and 2012). income played a significant role. 128 Consumers’ Perception and Willingness

RESEARCH APPROACH/ important (0) and not important (-1) METHODOLOGY was used to examine product attributes Data type and Sampling approach that inform the decision of consumers The study relied heavily on primary data to purchase Bansu. A three-point Likert and the target population for this study scale, agree (1), neutral (0), disagree was all consumers of non-alcoholic (-1) was also used to assess consumer’s beverage in Kumasi Metropolis. Three perception on Bansu based on ranking hundred (300) consumers were selected of series of perception statements for the study through a two-stage which were used to compute perception sampling technique. In the first stage, indices. all the communities in the Metropolis Willingness to pay (WTP) is a were put into strata based on their measure for signifying the maximum classification as high, middle and low monetary contribution an individual is income earning areas by KMA. Simple willing to offer in order to balance for random sampling technique was a change in his utility. This change in employed in selecting five communities utility is usually caused by a change in from each stratum. A total of 20 the level of some or several attributes respondents were selected from each of a good (Adamowicz et al., 1998). of the fifteen (15) communities using The study is based on consumer theory, convenience sampling technique. A with specific reference to willingness structured questionnaire was designed to pay. Consumer theory is about how to collect primary data from the sampled a consumer would reasonably make respondents. Data on consumers’ WTP consumption decisions (Levin and for Bansu was gathered by following Milgrom, 2004). Contingent valuation the double bounded bidding game and method is employed to obtain a with a sample of the product. consumer’s WTP for Bansu. Given that the responses are treated as random Data Analysis variables, the economic model needs Descriptive statistics such as mean, to incorporate a stochastic component standard deviation and frequency and the WTP distribution is linked to distribution tables, pie and bar the survey response probability under charts were used to summarize the the assumption that a consumer fully socioeconomic characteristics of the maximizes his/her utility (Carson and respondents. A three-point rating scale Hanemann, 2005). The cumulative namely, important (1), somewhat distribution function of WTP,Cd , and Consumers’ Perception and Willingness 129

the corresponding probability density random utility models (RUM). In the

function cd , depend on the format of RUM framework, the individual knows the survey question. For studies that with certainty his utility function (this employ the closed ended question implies that he knows his WTP) but, format, where individuals are asked given that these preferences are not whether they will pay a certain amount entirely observable to the researcher, of money, R, the probability that their they are treated as a random variable, so WTP is equal to or greater than this that the error term is directly included in amount is: the (indirect) utility function. Following Pr(WTP³=- R ) 1 C ( A ) the closed ended single bounded CV d question format, the probability that (1) the respondent answers yes can be The open-ended question format specified as in (3): assumes a linear regression on some Pr(es )= Pr( WTP ( q01 , q , p , ;e )³ A ) covariates (Zy) and a normally (3) 10 distributed random error (e), so that Pr{(,,vq p- A ;)ee ³ vq ( ,,;)}1 p=º- Cd () A WTP is also normally distributed as (4) indicated in equation (2): where q0 and q1 are scalars for the item being valued at the intial (0) and final (1) situations, p is the vector of WTP =mWTP += e ge + the prices of the market commodities, (2) y is the person’s income and A is the The second approach incorporates a amount of money being offered in the random term directly into the utility valuation question. function, in what has been known as 01 2 01 Let mWTP =E[ WTP ( q , q , p , ;es ),WTP = Var [ WTP ( q , q , p , ;e )] and let C(.) be the cumulative distribution function of the standardized covariate

w=(WTP - msWTP )/ WTP ; the probability function can be specified as in (5):

æöA- m Pr(es )=- 1 C WTP º-=1C ( -+gd A )= º ( A ) (ç÷ s ) èøWTP (5)

where gm= WTP/ s WTP and ss=1/ WTP . This expression, where the response to a closed ended CV survey is a function of a monetary amount, is consistent with an economic model of maximizing behavior “if and only if it can be interpreted as the survivor function of an economic WTP distribution” (Carson and Hanemann, 130 Consumers’ Perception and Willingness

2005). The double bounded model, proposed by Hanemann (1985) and Carson (1985), consists of asking a second bid (follow-up question) to the respondent.

If the respondent i answers yes to the first bid, 1i , the second bid 2i is higher, and lower if otherwise. The standard procedure, Hanemann (1985) and Carson (1985), assumes that respondents’ WTPs are independent of the bids and deals with the second response in the same manner as the first discrete choice question as indicated in (6): WW= and WW= (6) 10ii 20 ii

An individual answers yes to the first bid if W11ii> and yes to the second bid

ifW22ii> . Thus, the double bounded model assumes that the same random utility model generates both responses to the first and the second bid. As each individual is offered two separate bid opportunities, the simplest empirical strategy considers the combination of answers. Defining the potential outcomes

as i ={0, 1} = { no , es } yieldsi= {, ii12 }, the observed outcomes for each individual. Assuming rationality, an individual does not agree to pay more than they are willing; the set of observed responses yields a set of intervals for estimating W T P. Mathematically,

i={1, 1} = { es , es } Û³ wii 2 (7) (7)

i={1, 0} = { es , no } Û i12 £< w ii (8) (8)

i={0, 1} = { no , es } Û i12 >³ w ii (9) (9)

i={0, 0} = { no , no } Û< wii 2 (10) (10) To examine the consumer’s willingness to pay a premium for a product can be modelled using a Tobit regression model due to fact that the expected outcome of the consumer is likely to be censored. Theoretically, the Tobit regression model can be specified as in (11):

** ì P i =+> i be i , if P i 0 (11) :Pi =í * ( 0, if P i £ 0 ) î

where Pi is a censored dependent variable (indicating the proposed monetary amount that a consumer i who responds “YES-YES” or “YES-NO” or “NO-YES” Consumers’ Perception and Willingness 131

to the two bids and zero observation for “NO-NO”). i denotes consumer’s

socioeconomic characteristics and awareness of Bansu and εi denotes the error term. Following Owusu and Anifori specified empirically as in (12): (2015), the Tobit regression model was

ansu=+++aa Age a Sex a M_inc + a evedu + a PERn + a PERh + a PERp + a PERt + e i 01i 2 i 3i 4 i5 i 6 i 7 i 8 ii (12) (+) (+/-) (-) (+) (+) (+) (+) (+) manage the dataset collected and for Where ansui denotes an amount a consumer is willing to pay for 0.35litre estimating the Tobit regression model. of Bansu (Gh₵). Agei denotes age of respondent (years), Sexi denotes sex of FINDINGS respondent (1 if female and 0 otherwise). Consumers’ Attitude and Perception of Bansu M_ inci denotes income (Gh₵),

evedui denotes the number of years Table 1 represents summary of the

of formal education. PERhi denotes responses regarding consumers’ consumer’s perception on healthiness attitudes towards the attributes of of Bansu (1 if consumer agrees or 0 if Bansu. Consumers were asked to

otherwise), PERni denotes consumer’s rate the attributes of Bansu. Using a perception on nutritional content of three-point rating scales namely, not Bansu (1 if consumer agrees or 0 important (-1), somewhat important otherwise). PERt denotes consumers’ (0) and important (1). It was observed

perception on Bansu’s taste. PERpi that the sampled consumers regarded denotes consumers’ perception on the certain attributes of Bansu to be more

price of Bansu and ei denotes the important than others. The sampled consumers regarded the health benefit error term. a0 is the constant term and to be the most important followed a1,..., a10 denote the coefficients of the explanatory variables. by the FDB/Certification/Approval, The parameters in the Tobit taste, labelling/Appearance and price regression model were estimated of Bansu. Consumers are likely to through the maximum likelihood look for such attributes in that order estimation procedure. Stata and SPSS before purchasing Bansu. The results statistical software were employed to revealed that consumers’ purchasing (12) decision will not be dependent on the 132 Consumers’ Perception and Willingness

colour of Bansu. This implies that any those important attributes that affect investor who wants to enter into the consumers purchasing decisions. production of Bansu should consider Table 1: Consumers attitude towards the attributes of Bansu

Somewhat Important Not important Attributes important Mean Score (1) (-1) (0) Nutritional 290 (96.7%) 7 (2.3%)* 3 (1.0%) 0.96 benefits FDB certification 282 (94.0%) 11 (3.7%) 7 (2.3%) 0.92 Taste 266 (88.7%) 30 (10.0%) 4 (1.3%) 0.87 Labelling/ 266 (88.7%) 21 (7.0%) 13 (4.3%) 0.84 Appearance Price 264 (88.0%) 24 (8.0%) 12 (4.0%) 0.84 Flavor 260 (86.7%) 31 (10.3%) 9 (3.0%) 0.84 Low sugar level 254 (84.7%) 37 (12.3%) 9 (3.0%) 0.82 Shelf life 254 (84.7%) 27 (9.0%) 19 (6.3%) 0.78 Colour 162 (54.0%) 79 (26.3%) 59 (19.7%) 0.34 Source: Field survey, 2017 *Values in parenthesis are percentages Consumers were asked to give their attributes were categorized into three perception on the product based on main perception statements; health, services of statements. Perception nutritional and purchasing statements. index was computed to understand the Consumers’ responses with respect to overview of consumer’s perceptions the various perception statements are regarding the attributes of Bansu. The shown in Table 2. Consumers’ Perception and Willingness 133

Table 2: Consumer Perception on BANSU

Neutral Disagree Health Statements Agree (1) Mean score (0) (-1) Bansu is rich in minerals that are needed by the body to fight against 251 44 5 0.82 diseases due to the addition of sweet (83.7)* (14.7) (1.7) potatoes The sweet potato’s fiber, potassium, vitamin A and vitamin B-6 content 241 58 1 0.80 in Bansu, coupled with its lack of (80.3) (19.3) (0.3) cholesterol, all support heart health The Vitamin A in Bansu reduces the 253 41 6 0.82 risk of night blindness. (84.3) (13.7) (2.0) HEALTH PERCEPTION INDEX 0.81 (HPI) Nutritional statements 253 46 1 Bansu is nutritious 0.84 (84.3) (15.3) (0.3) 258 40 2 Bansu is rich in vitamin A 0.85 (86.0) (13.3) (0.7) Bansu is rich in dietary fibre due to 231 57 12 0.73 the fortification of sweet potatoes (77) (19.0) (4.0) 175 65 60 Bansu is low in sugar level 0.38 (58.3) (21.7) (20.0) NUTRITIONAL PERCEPTION 0.70 INDEX (NPI) Purchasing statements I am willing to pay for Bansu if 273 17 10 0.88 available (91.0) (5.7) (3.3) I am willing to pay for Bansu if price 245 30 25 0.73 is similar to related soft drinks. (81.7) (10.0) (8.3) I am willing to pay for Bansu if price 108 62 130 is increased a little above price of the -0.73 (36.0) (20.7) (43.3) related soft drinks I am willing to pay if Bansu is certi- 276 15 9 0.89 fied by FDA (92.0) (5.0) (3.0) Bansu is likely to be less expensive 239 33 28 compared to other soft drinks on the 0.70 (79.7) (11.0) (9.3) market I am willing to pay for Bansu if the 269 25 6 health claims are displayed on the 0.88 (89.7) (8.3) (2.0) product PURCHASING 0.56 PERCEPTION INDEX (PPI) OVER ALL MEAN 0.69 PERCEPTION INDEX Source: Field survey, 2017. Values in parenthesis are percentages. 134 Consumers’ Perception and Willingness

The results in the table show that blindness with 13.7% being neutral majority (83.7%) of the consumers to the statement. The mean perception indicated that they agree with the index for the health statement was 0.81 perception that Bansu is rich in minerals suggesting that consumers generally that are needed by the body to fight had a strong positive perception against diseases due to the addition regarding the healthiness of Bansu. of sweet potatoes. Moreover, 14.7% This demonstrates that the sampled took a neutral stance with only 1.7% consumers believe Bansu to be healthy. disagreeing to this same perception About 84% of the sampled consumers statement. The study also found that agreed that Bansu is nutritious. This can 80.3% of the consumers interviewed be attributed to consumers being aware agreed that Bansu contains fiber, of the inclusion of sweet potato. The potassium, vitamin A and vitamin B-6 result also indicated that 77.0% agreed coupled with its lack of cholesterol. The that Bansu is rich in dietary fiber due positive perception to this statement can to the fortification with sweet potatoes. be attributed to the fact that the orange- Those who disagreed to this statement fleshed sweet potato which was used accounted for only 4.0% with 19.0% in the preparation of Bansu contains taking a neutral position. With the high levels of vitamin A, vitamin B-6 sugar level, about 58.3% agreed that and potassium, and high content of Bansu has low sugar content. However, fibre from the sweet potato. However, about 20% disagree with that statement. 19.3% of consumer were indifferent The mean perception index for the about the statement, possibly due to nutritional statements was 0.70 which lack of information. Out of the 300 implies that consumers had a positive consumers interviewed, 84.3% agreed perception towards the nutritional that the vitamin A in Bansu reduces the content of Bansu. The mean perception risk of night blindness. The positive index for the nutritional statement is perception about this statement is lower than that of health statements because consumers were aware that indicating that consumers have more vitamin A deficiency leads to night positive perception on the health aspect blindness or poor eye sight. Consumers of Bansu than its nutritional aspect. therefore prefer to consume food that Again, 91% of the consumers contains high levels of vitamin A. indicated that they were willing to pay only 1% of the consumers disagreed for Bansu if it is made available due that Bansu reduces the risk of night to its health and nutritional benefits. Consumers’ Perception and Willingness 135

This means that majority of consumers displayed on the product. The positive will be willing to buy Bansu if more perception for this statements can also were available on the Ghanaian urban be attributed to fact that consumers market. People are now concerned are now very conscious of what they about their health and are therefore consume and therefore will like to find prepared to pay for commodities that out about the health benefits of the are healthy and nutritious. Out of the products, ingredient used and other 300 sampled consumers, 81.7% were vital information on the label. The mean willing to buy Bansu if price is similar purchasing perception index of 0.56 for to related soft drinks. 10.0% stood consumer purchasing behaviour shows neutral whilst 8.3% disagreed with the that consumers generally have positive statement. Interestingly, 36.0% of the perception towards purchasing Bansu consumers agreed to purchase Bansu though it is lower as compared to the if price was increased a little above mean health perception index and the the price of related soft drinks. A high mean nutritional perception index. percentage (92.0%) agreed to pay for Having the mean health perception the product with FDB certification. index to be highest, followed by the This implies that for a food to be safe nutritional and the purchasing indices for consumption it must be approved by makes the results similar to what Adu the Food and Drugs Authority (FDA). et al., (2015) found in their study on This also means a huge number of consumers’ perception and willingness the consumers have confidence in the to pay for sweet potato yoghurt. The FDA and their activities regarding food overall mean perception index was 0.69 safety. However, for some reason 3.0% indicating that in general, the sampled disagreed with 5.0% remaining neutral. consumers have positive perception Almost eighty percent (79.7%) towards the attributes of Bansu. This of the sampled consumers have the indicates that consumers would like to perception that Bansu should be less purchase Bansu when made available. expensive compared to other soft Consumers’ Willingness to Pay for drinks on the market. However, 9.3% Bansu disagreed and 11.0% took a neutral Consumers’ willingness to pay a stance. Moreover, almost ninety percent price for Bansu is summarized in Table (89.7%) of consumers were willing 3. The results in the table demonstrate to buy Bansu if they were labelled that more consumers are willing to pay or branded with the health claims for Bansu. Currently, the price for 350ml 136 Consumers’ Perception and Willingness

of Coca-Cola is GH₵2.00. Consumers expressed unwillingness to pay up to with the YES-YES responses were GH₵2.20 per 350ml. From the table willing to pay GH₵2.80. The results those consumers represented 41% of indicate that out of the 300 sampled the sampled consumers. Hence, 59% consumers, 86 (28.7%) of them were of the consumers were willing to pay at willing to pay GH₵2.80 for 350ml of least GH₵2.20 per 350ml of Bansu. The Bansu. Consumers with the YES-NO mean WTP from the pooled sample was responses were also willing to pay found to be GH₵2.62. Therefore, most GH₵2.50 for 350ml of Bansu formed of the consumers were willing to pay 25.7% of the sample only 4.7% (14) for the first bid (GH₵2.50). A standard of the consumers were not willing to deviation of 0.19 shows that most of the pay up to GH₵2.50 but something consumers were also willing to pay a lesser (GH₵2.20). Consumers with price closer to the mean price. (NO-NO responses) are those who Table 3: Distribution of consumer’s willingness to pay for Bansu Price (GH₵) per Response Frequency Percentage 350ml Yes-Yes 2.80 86 28.7% Yes-no 2.50 77 25.7% No-Yes 2.20 14 4.7% No-No <2.20 123 41% Mean WTP/350ml 2.62 ------Standard deviation 0.19 Consumers’ Perception and Willingness 137

Variables that were used in the Tobit regression have been summarized in Table 4 below. Table 4.5: Summary of the variables used in the Tobit regression model

Variable Definition Minimum Maximum Mean Age Age of respondents (Years) 14 73 31.17 Sex of respondent (1 if female, Sex 0 1 0.42 0 otherwise) Years of formal Years of formal education of 0 19 11.89 education respondents Monthly income of Monthly income 40 3700 707.99 Respondent Perception 1 if consumer has positive about Bansu perception about nutritional 0 1 0.84 being value/content of Bansu; 0 if nutritious otherwise Perception 1 if consumer perceives price about Bansu of Bansu to be cheaper than 0 1 0.80 being less Ex- that of substitutes; 0 if other- pensive wise Perception 1 if consumer has positive about Bansu perception about taste of 0 1 0.95 being of good Bansu; 0 if otherwise taste Perception 1 if consumer perceives Bansu about Bansu to be healthy/safe for 0 1 0.80 being healty consumption; 0 if otherwise Table 5: provides the Tobit regression income (M_inc), perception about

estimates for the determinants of Bansu being nutritious (PERni) and consumers’ willingness to pay for perception about the taste of Bansu ( Bansu. The empirical results show PERt ) had significant positive effect that LR Chi-square value (25.12) is on consumer’s WTP for Bansu. Age

statistically significant at 1% indicating (Agei) on the other hand had a significant that the explanatory variables included negative effect on consumers’ WTP for in the model jointly explain the variation Bansu. This is in commensuration with in consumer’s willingness to pay for what Dolgopalova (2016) asserted his Bansu. Among the factors included in work. Age was significant at 1% level with the implication that as one ages, the Tobit model, Sex (Sexi), Monthly 138 Consumers’ Perception and Willingness

his/her WTP for Bansu will be reduced constant by 0.0072, holding all other factors Table 5: Tobit Regression Estimates for the Determinants of Willingness to Pay for Bansu

Variable Co-efficient Std. Err. T-value Age -0.0072*** 0.002705 -2.66 Years of formal education -0.00519 0.007084 -0.75 Sex 0.176801*** 0.053606 3.31 Monthly Income of Respondent 0.000122*** 0.000043 2.85 Perception about Bansu being Nutritious 0.171961** 0.072913 2.36 Perception about Bansu being less expensive -0.0194368 0.065278 -0.30 Perception about Bansu being of good taste 0.239769** 0.118864 2.03 Perception about Bansu being healthy -0.04407 0.063597 -0.69 Cons 2.102624 0.198867 10.68 LR chi2(7) 25.12*** log likelihood -188.86058 Number of observation 300 Source: Field survey, 2017 ***=significant at 1%,** =significant at 5%.

CONCLUSION AND than others. The sampled consumers RECOMMENDATIONS regarded the health benefits to be the The study analyses consumers’ most important followed by the FDB/ willingness to pay for Bansu. Three Certification/Approval. It was revealed hundred consumers were selected that consumers will not base their from Kumasi Metropolis using a two- purchasing decision on the colour of stage stratified sampling technique. Bansu since it was the least important. Perception index was used to evaluate The study concludes that consumers’ perceptions concerning the consumers generally have positive attributes of Bansu. Tobit regression perception regarding Bansu in terms model was employed to examine factors of health, nutritional content and influencing consumers’ willingness to their willingness to pay. This may pay for Bansu. It was observed that the be due to the fact that consumers sampled consumers regarded certain are more conscious of their health attribute of Bansu to be more important and therefore, are more willing to Consumers’ Perception and Willingness 139

purchase commodities that are healthy non-alcoholic beverage (Bansu) should and nutritious. The empirical results be promoted by creating awareness also revealed that majority (59%) of among consumers on the nutritional consumers of NAB were willing to pay benefits of the product. The initial at least GH¢ 2.20 for 350ml of Bansu. promotion of the product should target The female gender, income level and consumers in high income communities positive perception about the taste since income level was found to be and the nutritional content of Bansu positively related to willingness to were found to influence consumers’ pay for the product. Also, younger willingness to pay positively. However, consumers (youth) should be targeted age had a significant negative effect during the initial promotion since age on consumers’ willingness to pay for of the consumer was revealed to have Bansu, all things being equal. a negative effect on willingness to pay. The general conclusion is that the Moreover, the product should be well new product developed from cassava packaged and well labeled with the and sweet potato (Bansu) by the Danida nutritional benefits displayed together root and tuber value chain project with Food and Drugs Authority (FDA) has bright market prospects in the Certification. The flavor should also be Kumasi metropolis and similar urban improved since consumers complained settings in Ghana.The study therefore about the natural flavor felt after recommends that cassava-sweetpotato consumption. 140 Consumers’ Perception and Willingness

REFERENCES

Adamowicz, W.L., Boxall, P.C., Williams, M. and Louviere, J. (1998). ―Stated Preference Approaches for Measuring Passive Use Values: Choice Experiments and Contingent Valuation, American Journal of Agricultural Economics, 80: 64- 75 Adu, E., Acheampong J.O, Agyapomaa L.A, Ackun P.A, Asimeng, A.A. (2015). Consumer’s perception and willingness to pay for sweet potato yoghurt (potagurt). Unpublished undergraguate thesis, submitted to the Department of Agricultural Economics, Agribusiness and Extention, Kwame Nkrumah University of Science and Technology, 2015). Agyekum, C.K, Haifeng, H &Agyeiwaa, A. (2015). Consumer Perception of Product Quality. Microeconomics and Macroeconomics, 3(2168-4588), 25-29. Angulo, A.M., Gil, J.M. and Tamburo, L. 2003. Food safety and consumers’ willingness to pay for labeled beef in Spain. Paper presented at the 83rd EAAE Seminar, Chania, 4-6 September. Barreiroa J., Sanchez, M. and Viladrich-Grauc, M. (2005) How much are People Willing to Pay for Silence? A Contingent Valuation Study. Applied Economics ISSN 0003–6846 print/ISSN 1466–4283 Taylor & Francis Group Ltd. pp 1244 Chen, H. and Chern, W. S. (2002). Consumer Acceptance of Genetically Modified Foods. Paper Presented at the Annual Meeting of the American Agricultural Economics Association, 28–31 July, 2002, Long Beach, CA. Coggins PC, Kelly RA, Wilbourn JA (2003) Juice yield of sweet potato culls. Session 104C, Fruit and Vegetable Products: Vegetables (Processed). 2003 IFT Annual Meeting – Chicago, USA. Cuomo, R., Grasso, R., Sarnelli, G., Capuano, G., Nicolai, E., Nardone, G., Pomponi, D., Budillon, G. and Ierardi, E., 2002. Effects of carbonated water on functional dyspepsia and constipation. European journal of gastroenterology & hepatology, 14(9), pp.991-999. Dannenberg, A. (2009). The dispersion and development of consumer preferences for genetically modified food — A meta-analysis. Ecological Economics, 68(8-9), 2182–2192. doi:10.1016/j.ecolecon.2009.03.008 Darby, K, Batte, M.T., Ernst, S. and Roe B. (2006), Willingness to Pay for Locally Produced Foods: A Customer Intercept Study of Direct Market and Grocery Consumers’ Perception and Willingness 141

Store Shoppers. Department of Agricultural, Environmental and Development Economics, the Ohio State University. pp 9-12. Fang, P. (2015). Evaluating Consumer Response to Labels and Packaging in the Market for Baby Foods. Fathelrahman, E., Hussein, A., Muhammad, S., &Sherif, S. (2015). Supply and Demand for Fresh Locally Produced Poultry Products in United Arab Emirates. Journal of Food Distribution Research, 46(1). Florax, R. J. G. M., & Nijkamp, P. (2005). A meta-analysis of the willingness to pay for reductions in pesticide risk exposure. In American Agricultural Economics Association Annual Meeting, Providence, Rhode Island, July 25-27. Hanemann, W. (1985). Some issues in continuous and discrete response contingent valuation studies. Northeast Journal of Agricultural Economics, 14, 5–13. Hellyer, N. E., Fraser, I., & Haddock-Fraser, J. (2012). Food choice, health information and functional ingredients: An experimental auction employing bread. Food Policy, 37(3), 232–245. Institute of Medicine (2012). Accelerating Progress in Obesity Prevention: Solving the weight of the Nation. Washington, DC: National Academies Press. Irina Dolgopolova, Technical University of Munich (Germany), irina.dolgopolova@ tum.de Jerop, R., Kosgey, I. S., Ogola, T. D., & Opondo, F. A. (2014). Consumers’ Perceptions Towards Goat’s Milk: Exploring the Attitude Amongst Consumers and Its Implication for a Dairy Goat Breeding Programme in Siaya County, Kenya. European Journal of Business and Management, 6, 221-229. Liu Y, Zeng, Y. and Yu, X. (2009). Consumer Willingness to Pay for Food Safety in Beijing: A Case Study of Food Additives. Contributed Paper Prepared for Presentation at the International Association of Agricultural Economists Conference, Beijing, China, August 16-22, pp 6-15 Lusk, J. L., Jamal, M., Kurlander, L., Roucan, M., & Taulman, L. (2005). A Meta- Analysis of Genetically Modified Food Valuation Studies. Journal of Agricultural and Resource Economics, 30(1), 28–44. Munene, C. N. (2006). Analysis of consumer attitudes and their willingness to pay for functional foods (Doctoral dissertation, Louisiana State University). Nordström, J. (2012). Willingness to pay for wholesome canteen takeaway. Appetite, 58(1), 168–79. doi:10.1016/j.appet.2011.08.022 Oviahon, I., Yusuf, S., Akinlade, J. and Balogun, O. 2011. Determinants of Bread Consumers’ Willingness to Pay for Safety Labels in Oredo Local Government Area, Edo State, Nigeria. New York Science Journal, 4(9). Owusu, V. and Anifori, M.O. (2013). Consumer willingness to pay a premium for organic 142 Consumers’ Perception and Willingness

fruit and vegetable in Ghana. International Food and Agribusiness Management Review, 16(1): 67-87. Oyimbo, W. (2013). Cassava as a poor man’s food. http://scripts.farmradio.fm/radio- resource-packs/package-96-the-root-of-life/cassava-a-poor-mans-crop-no-longer/. [Accessed: 13-08-16]. Pouratashi, M. (2012) ‘Factors Influencing Consumers’ Willingness to Pay for Agricultural Organic Products (AOP)’, pp. 371–376. Teratanavat, R., & Hooker, N. H. (2005). Exploring Consumer Valuation and Preference Heterogeneity for Functional Foods Using a Choice Experiment: A Case Study of Tomato Juice Containing Soy in Ohio. In American Agricultural Economics Association Annual Meeting. Providence, Rhode Island WHO. Guideline: Sodium intake for adults and children. Geneva, World Health Organization (WHO), 2012. Williams II, D.R. and Schiek, W.A. (2000). Consumers’ willingness to purchase locally produced agricultural products: An analysis of an Indiana survey. Agricultural and Resource Economics Review, 29(8): 3–53. Wireko-Manu FD, Agyare A, Agbenorhevi JK, Oduro I (2016). Development and Quality Assessment of Cassava-Sweet Potato Non-Alcoholic Beverage. MOJ Food process Technol 2(3): 00040. Worldatlas (2016). Countries with the highest levels of Soft Drink Consumption. http:// www.worldatlas.com/articles/countries-with-the-highest-levels-of-soft-drink – consumption.html [Accessed: 26-03-17]. 143

The Effect of Training on Extension Delivery and Performance of Agricultural Extension Agents (AEAs) under RTIP

J.A. Bakang1 and C.K Osei2 1Department of Agricultural Economics, Agribusiness and Extension, KNUST 2Institute of Distance Learning, KNUST

Abstract An experimental evaluation model was and documentary reviews. The two adopted in this study which sought approaches were compared using: (i) to determine whether differences trainee AEA reactions to selected indices existed in the effectiveness of training of the pooled-training programme under Root and Tuber Improvement under the normal extension delivery (ii) Programme (RTIP) in respect of two assessment of extension effectiveness extension approaches: the normal indicators by both farmers and AEAs extension delivery which is essentially covering visits, field meetings, field the modified. Training and Visit days, and demonstrations, as well as (T&V), and the Farmer Field School other beneficiary indicators including (FFS). Three hundred cassava and one increased production, decreased cost of hundred potato farmers were selected production, reduced disease incidence, as the study sample from four districts profit and return on investment, and in which the full complement of RTIP yield. FFS graduates, as compared to training had been undertaken. The study those who did not participate and were sample also included a complete survey presumed under the normal extension of fifty-two Agricultural Extension delivery system rated AEAs involved Agents (AEAs) from the four in FFS higher on most extension selected districts. Data collection effectiveness indicators. By farmers’ was accomplished through the and AEAs’ assessments, significant administration of questionnaire surveys, differences were found on several informal interviews and discussions extension effectiveness indicators to suggest that the FFS approach had 144 The Effect of Training on Extension Delivery and Performance

better impact on the performance of poor farmers on a sustainable basis by the target beneficiaries. To improve facilitating their access to improved the performance of AEAs in RTIP and locally adapted technologies of implementation and the adoption root and tuber crops (cassava, yam, of improved technologies by target cocoyam, sweet potato, and Frafra beneficiaries, the most important potato). Through the activities of constraint mentioned by the majority the programme, 720,000 resource- of AEAs – lack of market demand for poor farmers were expected to access RTIP cassava – and conversely the planting materials of the improved most important measure suggested by cassava and sweet potato varieties by farmers to improve their benefits from the end of the six-year period, which cassava production – offering assistance ended in December 2004. in the marketing of cassava – as well as The Community Support and other constraints such as the provision Mobilisation Component, one of of adequate logistics to AEAs for their six components through which the work, and encouragement and advice programme was implemented was from AEAs through the FFS approach charged with empowering resource- should be addressed. These constraints poor farmers, farmer groups and rural provided some of the bases for the communities including women, to formulation and subsequent appraisal ensure unimpeded access to planting and implementation of the second materials of the improved varieties of phase of root and tuber improvement root and tuber crops and technology. programme, which emphasised on Under this component, various roles marketing. were assigned to the Agricultural ExtensionAgents (AEAs) of the Ministry Background of Food and Agriculture (MOFA). The Ministry of Food and Agriculture The AEA was primarily responsible (MOFA) implemented the Root and for organising farmers, processors, Tuber Improvement Programme (RTIP) traders and end users into groups to over six years (from January 1999) with supply the farmers with improved a GOG/IFAD funding to the tune of planting materials for multiplication. US$10.1million. The overall objective They were also to promote group of the programme, which was national cohesion and support the groups with in scope, was to enhance food security technical advice. The Integrated Pest and increase the incomes of resource- Management (IPM) Component, was The Effect of Training on Extension Delivery and Performance 145

charged with developing an integrated this training programme was to enhance pest management system which group formation to enable farmers to includes biological control to reduce access improved planting materials of the incidence of diseases and pests as root and tuber crops through the use of well as increase the productivity of PRA tools, good communication and smallholder root and tuber crop systems. gender sensitisation. This was followed The IPM component on the other hand, by two training review workshops for used the Farmer Field School (FFS) trainers of the Northern and Southern approach on a pilot basis to train sector groups of staff respectively in farmers in becoming IPM experts in 2001. Participatory monitoring and tackling pests and diseases outbreaks evaluation was included in the course within their communities. AEAs for content of the review workshops, with these communities were trained on the Regional Development Organization IPM principles and criteria prior to – Monitoring and Evaluation Officers implementing the FFS in the selected (RDOs-M&E) participating for the first communities. The focus of this study time – probably as an after-thought. was to comparatively assess the two Following this training of trainers’ approaches used in the RTIP training workshops, the RTTs then conducted programme for AEAs: the pooled- pooled training sessions for all AEAs training programme and the FFS. in the operating districts of RTIP. RTIP training for AEAs under The subject matter content for the normal extension delivery system the RTIP pooled-training programme involved pooled-training given to all consisted the following: Principles AEAs in RTIP operating districts to and concepts of PRA; PRA tools and mainstream knowledge and skills in techniques; Fieldwork or Field practice certain subject matter content areas sessions; Gender issues; Group with the aim of achieving appropriate formation; Effective communication; behavioural changes in their normal and Monitoring and evaluation. Training extension work. To achieve this, a was organised and coordinated by the strategy was adopted which involved Community Support and Mobilisation training of Regional Training Teams Component. (RTT) who were then in turn to conduct The second approach used training for AEAs. The first of such Farmer Field Schools (FFS) piloted training of trainers’ workshops was held in selected communities in all the in the year 2000. The main objective of RTIP zones. As a pilot, training for the 146 The Effect of Training on Extension Delivery and Performance

implementation of the cassava FFS in 1. Assess the reaction of trainee AEAs particular was limited to the few AEAs to the pooled training programme whose communities were selected and and the training for the facilitation covered the following subject matter of FFS under RTIP. content: Cassava Agro ecological 2. Determine the extent to which system analyses (AESA); Identification participants changed attitudes, of cassava varieties and plant spacing. improved knowledge, and/or Unlike the pooled-training programme, increased skills as a result of FFS were organised and controlled by attending the pooled training the Integrated Pest Management (IPM) programme and/or the training Component of RTIP and emphasis programme for FFS. naturally was on pest and disease 3. Determine the extent to which management. The 2-3 day training change in behaviour has occurred for extension personnel prior to the because participants attended the FFS implementation involved one or pooled training programme, with two AEAs, the RTIP Desk Officer, the particular reference to: District Development Officer (DDO) (a) The quality of work of participants and supervisor of the selected AEA (b) Farmers’ practices and increased and the District Director of Agriculture production, decreased cost, reduced (DDA). One major assumption for this frequency and or severity of disease short duration of training for the FFS incidence, and implementation was that the extension (c) Higher profits and return on officers already had more than adequate investment. knowledge and skills in cassava 4. Compare the changes in behaviour agronomy and production. for AEAs involved in FFS and those in the normal extension under RTIP. Objectives of the Study The objective of this study was to assess METHODOLOGY the effectiveness of RTIP training of This section outlines the theoretical AEAs under the modified training and framework under which this evaluation visit (T&V) extension delivery and in study was carried out as well the ensuing Farmer Field Schools (FFS), and the research design, sampling procedure, performance of target beneficiaries. data collection instruments and data Specifically, the study was to: analyses. The Effect of Training on Extension Delivery and Performance 147

Theoretical Framework and a cross-sectional study is that data can Research Design be gathered from a large number of The experimental evaluation model was people and these data are comparable adopted in this research which sought since they are not affected by changes to determine whether differences exist over time (Bailey, 1987). The field in the effectiveness of training under data was collected within a period of RTIP in respect of the two extension 3 weeks and thus was not affected by approaches: the modified training and changes in time between collection of visit extension delivery and the FFS. information from one respondent to The two approaches were compared another. Respondents (both farmers using: (i) trainee AEA reactions and AEAs) were classified into the to selected indices of the pooled- categoryof those who participated in training programme using Likert – the FFS and those who did not (and type scales (ii) assessment of single thus assumed as under the modified extension effectiveness indicators training & visit extension delivery) by both farmers and AEAs covering were asked to assess these indicators visits, field meetings, field days, and qualitatively and their responses were demonstrations. Due to the absence then subsequently compared under the of reliable data usually available from two approaches. adequate and appropriate monitoring, extension efficiency indicators Sampling Procedure, Instruments (Casely & Lury, 1982) – performance, and Data Collection penetration, and achievement indices The target population was taken as all could not be used. For similar reasons farmers and AEAs in the RTIP districts as above, the productivity index (Misra, where the full complement of the 1997) could not also be calculated. The pooled training programme and FFS yield index (Misra, 1997) for FFS and training for AEAs had been conducted. non-FFS farmers, which was determined In sampling, two techniques were in one of the RTIP evaluation studies used to select the sample. Purposive (Nurah & Ahiale, 2004) has been cited sampling technique was used in the appropriately. selection of four (4) districts, out of the A cross-sectional study design eighteen (18) RTIP Districts to capture using survey of the descriptive type was the best and the worst performing (by employed to collect data from AEAs the Programme Coordinating Office’s and farmers. The basic advantage of evaluation), cassava and sweet potato 148 The Effect of Training on Extension Delivery and Performance

production, FFS training and across were not employed as enumerators in ecological zones. The four selected this survey. The various questionnaires districts (in consultation with RTIP (for farmers and AEAs) were pre-tested Programme Coordinating Office) were in a district other than the selected study as follows: districts (Techiman). 1. Wenchi – FFS District Data Analysis 2. Ejisu-Juaben – FFS District Data was first collated and coded before 3. Ejura – Sekyedumasi, and entry into the computer for analysis 4. Bawku East using the SPSS. Frequencies and Random sampling technique percentages were used to summarise was used to select the respondents of data collected on trainee reactions, the study. Four hundred (400) farmers KASA (Knowledge, Attitudes, Skills consisting of one hundred (100) and Aspirations) changes and the farmers from each of the districts and extent to which these changes occurred 52 AEAs were selected to give a total under the two approaches. To compare of four hundred and fifty-two (452) these changes for AEAs involved in respondents. The following instruments FFS and those involved in the normal were identified as the most appropriate extension under RTIP, test of means for the data collection and were used in using ANOVA was employed. The chi- this study: square test of independence was used 1. Questionnaires as the main statistical tool to determine 2. Informal Key informant whether differences found between interviews and group discussions farmers in respect of the extension 3. Literature and documentary review effectiveness indicators under the two Literature and documentary review was approaches were purely due to chance. accomplished with visits to Programme In all cases, the 0.01 level of significance Coordinating Office (PCO) where all was adopted in rejecting or accepting the materials used were obtained. A the a priori assumption that the two reconnaissance survey was conducted approaches do not differ in respect of during which RTIP Desk Officers the extension indicators under scrutiny. and District Directors of Agriculture (DDAs) were informally interviewed, after which questionnaires were then administered. To avoid bias, AEAs who were to be assessed by farmers The Effect of Training on Extension Delivery and Performance 149

RESULTS AND DISCUSSION number of 52 AEA-respondents by Following a summary of general district is shown in Table 1a. Out of information on the personal this total number, about 10% were characteristics of the AEA respondents, female (Table 1b). Sixty percent (60%) the results and discussion is organised of the AEAs were aged between 26 into three parts:(i)reaction of trainee and 45 years (Table 1c) while the AEAs to the pooled-training programme remaining 40% were aged between and the training for the facilitation of 46 and 60 years. Majority of the FFS under RTIP respondents (over 84% in each case) (ii) the extent to which participants were Christian, married and had the changed behaviour, attitudes, improved Agricultural College Certificate (Tables knowledge and or increased skills 1d-f). Educational levels reported by as a result of attending the pooled- respondents indicate that only 9.6% training programme and or the training of AEAs had the Diploma Certificate programme for FFS while 5.8% were university graduates (iii) comparison between the changes awaiting re-designation or had other in behaviour for AEAs involved in the qualification. From field experience of FFS and those involved in the normal the authors, these statistics on sex and extension under RTIP. age distribution, educational levels, General information on the marital status and religious affiliation, characteristics of AEAs include the are a fair reflection of the countrywide distribution of respondents by district, data on AEAs. sex, age, marital status; educational Forty-three out of the 52 AEAs levels, FFS participation and whether in the survey (representing 83%) AEA respondents were beneficiaries participated in the RTIP pooled training of RTIP pooled training or not.A sessions (Table 1g). From Table 1h, it complete survey was planned for AEAs is observed that of the nine (9) non- in all the selected districts and enough participants, three (3) reported they questionnaires were distributed for the had not yet been employed while five purpose. However, one or two AEAs in (5) were not aware of the training. Bawku and Ejisu-Juaben districts did Not being aware of RTIP pooled- not complete the questionnaire. General training sessions in one’s district could information on AEAs is summarised in be as a result of transfer from a non- Table 1(a – h). RTIP district or absence due to study The distribution of the total leave. Only one AEA did not give any 150 The Effect of Training on Extension Delivery and Performance

response when asked for the reasons characteristics (duration, facilities and for not participating in the RTIP pooled general management). Respondents training. were also asked to rate the usefulness of Reaction of Trainee AEAs to the subject matter content of the training RTIP Training Programme to their work and finally, respondents’ The reactions of AEAs who reactions on the extent to which the benefited from the RTIP pooled- knowledge and skills acquired in the training programme were sought training was applied in theirwork was on the competence of their trainers, assessed. The reactions were assessed the effectiveness of the teaching using Likert-type scales consisting four and facilitation methods used in the items in each case. Summaries of their training sessions in promoting learning ratings are shown in Tables 2 – 4. and the general training programme The Effect of Training on Extension Delivery and Performance 151

Table 1: Characteristics of AEAs Respondents

PERCENTAGE CUMULATIVE VARIABLES FREQUENCY (%) (%) DISTRICT (a) Bawku 9 17.3 17.3 Ejura-Sekyeredumasi 15 28.8 46.2 Wenchi 15 28.8 75.0 Ejisu-Juaben 13 25.0 100.00 Sex of Respondents (b) Male 47 90.4 90.4 Female 5 9.6 100.00 Age Distribution of AEAs (c) 26 – 45 31 59.6 59.6 46 – 65 21 40.4 100 Level of Education (d) Agric. College Certificate 44 84.6 84.6 Diploma 5 9.6 94.2 Others 3 5.8 100.0 Religious Affiliation of AEAs (e) No religion 1 1.9 1.9 Christian 45 86.5 88.5 Moslem 6 11.5 100.0 Marital Status of AEAs (f) Single 6 11.5 11.5 Married 44 84.6 96.2 Widowed 1 1.9 98.1 Divorced 1 1.9 100.0 AEAs Participation in Pooled training Programme (g) Yes 43 82.7 82.7 No 9 17.3 100.0 Reasons Why No Participation in Pooled Training (h) Had not been employed 3 33.3 33.3 Wasn’t aware of training 5 55.6 88.8 No response 1 11.1 100 Source: Field Survey Data, November 2004 152 The Effect of Training on Extension Delivery and Performance

Assessment of Trainers as competent, 16% as very competent Competence by AEAs and only 12% as somehow competent. AEA trainees’ assessment of the No trainee assessed the trainers as trainers in the RTIP pooled training incompetent. It is worthwhile to note programme shown in Table 4 shows that all the trainers in the pooled training that beneficiaries had a high assessment programme first underwent training (more than 88%) of the competence organised by RTIP in its strategy of of the trainers. Seventy-two percent mainstreaming through RTTs. (72%) of the trainees rated the trainers Table 2: AEAs Rating of Trainers Competence in the RTIP Pooled Training Programme

Competence of RTIP Trainers Rating by Participating AEAs Freq. % Somehow competent 5 11.6 Competent 31 72.1 Very competent 7 16.3 Total 43 100.0

Assessment of Effectiveness training programme were positive. of Trainers use of Training and Majority of the respondents thought the Facilitation Methods teaching and facilitation methods and Table 3 shows that AEA trainees’ the practice sessions were effective in reactions to the teaching and facilitation promoting learning. This collaborates methods employed by the trainers with the high assessment of the in promoting learning in the pooled competence of the trainers. Table 3: AEAs’ rating on the effectiveness of training and facilitation methods

Rating by participating Training / facilitation methods and field practice AEAs Teaching methods Facilitation Practice sessions (N= 43) % % % Not effective 4.6 2.3 2.3 Somehow effective 23.3 16.3 34.9 Effective 60.5 74.4 53.5 Very effective 11.6 7.0 7.0 No response - - 2.3 Total 100 100 100 The Effect of Training on Extension Delivery and Performance 153

Assessment of AEA Reaction for the training programme was rather to the General Training too short for the subject matter covered. Programme Characteristics As shown in Table 4, up to 70% of Assessment of trainee reactions to the the respondents rated the duration as duration of the training, facilities on inadequate or somehow adequate. A offer during the training and the general majority of the trainees (more than management of the training were 50% in each case) assessed both the mixed. Majority of the respondents facilities and the general management insisted that the average 2-day duration of the training programme as adequate. Table 4: Rating of general programme characteristics of RTIP pooled-training programme by AEAs Training Programme Characteristic Rating by participating AEAs Duration Facilities Management (N= 43) % % % Inadequate 32.6 13.9 4.6 Somehow adequate 27.9 25.6 37.2 Adequate 37.2 53.5 51.2 Very adequate 2.3 7 7 Total 100 100 100

Effect of RTIP Training on the the usefulness of the subject matter Extent of KASA and Behaviour content of the training as well as the Changes in Trainee AEAs extent to which the knowledge and In this part, the extent to which skills gained are applied in their work, changes in knowledge, attitudes, are a good reflection of their attitude skills and aspirations with consequent and consequent behaviour towards the changes in behaviour of AEAs have training in particular. Secondly, it could occurred because participants attended be argued that farmers are the best judges the pooled training programme, or when it comes to the AEAs serving took part in the FFS, with particular them, and their assessment should be reference to the quality of work of the most important. Assessment of the participants are presented. It could effect of RTIP training on AEAs was be argued that AEAs’ perception of therefore based on these premises. 154 The Effect of Training on Extension Delivery and Performance

AEA reaction on the usefulness importance they were likely to attach to of the subject matter content the knowledge and skills ensuing there to their work from, and consequently, the seriousness Rating on the usefulness of the subject they would attach to behavioural matter content of the RTIP pooled changes expected to accompany training programme to their work by such training and their subsequent trainee AEAs has a direct bearing on the application in their normal work. Table 5: Rating on the usefulness of the subject matter content of the RTIP pooled- training programme by AEAs Rating by participating Subject matter content of training programme* AEAs 1 2 3 4 5 6 7 (N= 43) % % % % % % % Not useful - - - 2.3 2.3 2.3 7.0 OK 16.3 18.6 18.6 32.6 16.3 23.2 30.2 Useful 44.2 55.8 39.5 48.8 41.9 46.5 37.2 Very useful 39.5 25.6 39.5 16.3 37.2 28.0 25.6 No response - - 2.3 - 2.3 - - Total 100 100 100 100 100 100 100

Key Þ however, monitoring and evaluation as 1: Principles and concepts of PRA; subject matter was the highest rated as 2: PRA tools and techniques; not useful – up to 37% considering it 3: Fieldwork or Field practice session; either not useful or just OK. It was also 4: Gender issues; the least rated as useful or very useful 5: Group formation; (62.8%). The ensuing unfortunate 6: Effective communication; behaviours and attitudes emanating 7: Monitoring and evaluation from this are the poor knowledge and In this respect, it could be argued skills in monitoring and evaluation, that in general, more than half the which is reflected in the complete lack respondents showed a positive attitude of basic monitoring data expected from (useful and very useful) to all the subject the AEAs. matter areas covered in the training programme (Table 5). Comparatively The Effect of Training on Extension Delivery and Performance 155

AEAs’ reaction on the extent subject matter areas, with the exception to which knowledge and skills of monitoring and evaluation, as being gained in the RTIP pooled- quite or very much applied. Monitoring training programme are and evaluation was rated by as much applied in their work as 46% of the respondents as not being When AEAs were asked to rate the applied much or OK. Conversely, it was extent to which the knowledge and the least rated as being quite or very skills gained in the various subject much applied (48.8%) in their work. matter content areas of the RTIP These ratings are consistent with the pooled-training programme are applied earlier assessment of the subject as not in their normal work (Table 6), majority being useful in their work. of them (almost 70% or more) rated the Table 6: Rating by AEAs on the extent to which knowledge and skills gained in the RTIP pooled-training programme are applied in their work

Rating by participating Subject matter content of training programme* AEAs 1 2 3 4 5 (N= 43) % % % % % Not much 2.3 - 7.0 7.0 16.3 OK 23.3 27.9 18.6 30.2 30.2 Quite much 39.5 46.5 37.2 34.9 27.9 Very much 32.6 23.3 34.9 25.6 20.9 No response 2.3 2.3 2.3 2.3 4.6 Total 100 100 100 100 100

Key Þ Eleven of the 52 AEAs interviewed 1: Principles, concepts, tools and techniques of PRA; received training to implement FFS in 2: Gender issues; their communities. When asked to rate the extent to which the knowledge and 3: Group formation; skills gained in the FFS training are 4: Effective communication; applied in their work, 81.8% of FFS 5: Monitoring and evaluation graduates indicated that they applied the knowledge and skills gained quite and very much (Table 7). 156 The Effect of Training on Extension Delivery and Performance

Table 7: Training of AEAs under the FFS

Variable Frequency % Cumulative % FFS Graduate Yes 11 21.2 21.2 No 41 78.8 100 Rating by AEAs on the extent to which knowledge and skills gained are applied in their work (N = 11) Not much 0 0 0 OK 2 18.2 18.2 Quite much 4 36.4 54.6 Very much 5 45.4 100 Source: Field Survey Data, 2004. General effect of RTIP training on AEA performance RTIP training for AEAs had been attribute directly to the effect of RTIP completed before 2003. Respondents training in this assessment, 60% of the were therefore asked to rate the farmers thought that the performance performances of their AEAs in year of their AEAs had improved over 2003 as compared to previous years previous years, 30% thought it was the they had not undergone the training. same as before while only 7% thought Table 8shows the rating given by the the performances of their AEAs had farmer respondents in their assessment. become worse than before. Again, although there is no evidence to Table 8: Farmers’ rating of AEA performance in year 2003 (after RTIP training)

Farmers’ rating of AEA performance Frequency % Cumulative % Worse than before 21 7.0 7.0 Same as before 91 30.3 37.3 Better than before 181 60.3 97.7 No response 7 2.3 100.0 Total 300 100.0 The main objective of the RTIP pooled- access improved planting materials of training programme was to enhance root and tuber crops and other support group formation to enable farmers easily such as processing. Farmer respondents The Effect of Training on Extension Delivery and Performance 157

were therefore asked whether they who initiated the group. The results are belonged to a farmers’ group, how many summarised in the following Table 9. years they have been in the group and Table 9: Summary of Farmer Group Membership

Variable Frequency % Cumulative % Farmer Group Membership Yes 250 83.3 83.3 No 50 16.7 100 Initiation of Respondents’ Membership of Farmer Groups AEA 173 69.2 69.2 Chief 6 2.4 71.6 Neighbour 48 19.2 90.8 Husband 1 .4 91.2 Self 13 5.2 96.4 Other 8 3.2 99.6 No response 1 .4 100 Number of years in farmer group membership Less than a year 4 1.6 1.6 1-5 years 207 82.8 84.4 6-10 years 26 10.4 94.8 11-15 years 2 .8 95.6 No response 11 4.4 100 Source: Field Survey Data, November 2004 From Tables 9, it is clear that 83% upsurge during RTIP implementation. of the respondents belong to farmer Respondents were asked how often groups with an equal proportion (83%) their AEAs visited them at home and of members joining in the last five in the field in year 2003 as an indicator years and 69% of all the groups being of AEA performance. The results are initiated by AEAs. The idea of working shown in Table 10. In both cases (Home with farmers in groups is not a new one and Field visits), the regularity of visit under the extension delivery system in when arranged from highest to lowest Ghana. Although one may argue that the is as follows: fortnightly, weekly, evidence of the effect of RTIP training monthly, quarterly (once in 3 months), is not direct in this respect, coincidence bi-annually, and annually. alone cannot explain this sudden 158 The Effect of Training on Extension Delivery and Performance

Table 10: Respondents’ assessment of the regularity of visits by their AEAs in 2003

% Proportion of respondents Regularity of AEA visits Home Field % Rank % Rank Once a week 17.0 2 22.0 2 Once a fortnight 33.3 1 26.3 1 Once a month 16.3 3 14.7 3 Once in 3months 12.7 4 9.3 4 Once in 6months 4.3 5 5.7 5 Once in a year 2.3 6 2.0 6 No response 14.0 4* 20.0 3* Total 100.0 100.0 This low assessment reflects AEA visits AEAs’ perceived constraints under the normal extension delivery and the measures to improve system of modified T&V in which a RTIP implementation substantial proportion of farmers are AEAs were finally asked to suggest never reached simply because of the what, in their opinion, constituted low extension agent to farmer ratio in constraints to the implementation Ghana. The “no response” category of RTIP in their operational areas. could well refer to those who are never Analyses of their suggestions (Table visited during an entire year and if 11) indicate that the major constraint included in the ranking, place fourth identified by 65% of the respondents and third respectively (4* and 3*) for was lack of or low market demand home and field visits. for RTIP cassava. Similarly, provision of adequate logistics to AEAs for their work, and encouragement and advice from AEAs through FFS, were identified as important measures which, in their opinion, will improve their performance in RTIP implementation and the adoption of improved technologies by target beneficiaries. The Effect of Training on Extension Delivery and Performance 159

Table 11: AEAs’ perceived constraints and measures to improve RTIP implementation

Perceived constraint / measure(s) Respondents’ Lack of market AEA Provision of adequate perception demand for RTIP encouragement and logistics for AEAs category cassava advice through FFS Frequency % Frequency % Frequency % Yes 34 65.4 27 51.9 18 34.6 No 18 34.6 24 46.2 33 63.5 No response 0 0.0 1 1.9 1 1.9 Total 52 100.0 52 100.0 52 100.0

Comparison between the Comparison between AEA Behaviour and KASA Changes participants of FFS and in AEAs involved in the FFS non-FFS participants and those involved in the Table 12 is a summary of the test of means Normal Extension under RTIP results (ANOVA) of selected indicators Section 3.3 presents a summary comparing AEA FFS participants and comparison of indicators used to assess non-participants. The summary shows the behaviour and KASA changes that indicators or variables marked not between AEAs who participated in the significant implies that it did not matter pilot FFS and those who did not and whether one is a FFS participant or not were thus presumed to be working with regard to the specific indicators. under the normal extension delivery It is clear from this summary that system of modified T&V. The a differences in the number of farmers priori assumption is that there are no adopting cassava disease control differences between AEA participants measures in the operational areas of of FFS and non-participants with AEA FFS participants on the one regard to the indicators for measuring hand and non-participants on the other the effectiveness of extension. The were highly significant. Farmers in the results are presented and discussed in operational areas of FFS-participating the following subsections. AEAs adopted cassava disease control measures more than in the operational areas of non-participating AEAs. Similarly, differences in the number of 160 The Effect of Training on Extension Delivery and Performance

farmers adopting cassava pest control areas of non-participating AEAs. This measures in the operational areas of confirms that the content of the FFS AEA FFS participants on the one training paid more attention to pest and hand and non-participants on the other disease control – having been handled were highly significant. Farmers in the by the IPM Component. There is the operational areas of FFS-participating need to review the FFS curriculum AEAs adopted cassava pest control to include all issues along the whole measures more than in the operational value-added chain. Table 12: Summary of ANOVA: AEA FFS Participant/Non-participants

VARIABLES F VALUE SIGNIFICANCE CONCLUSION 1. Number of cassava or potato farmers reached with RTIP messages in OPA .245 .623 Not significant in 2003 * are you a farmer field school participant 2. Number of farmers adopting improved varieties * Are you a cassava/potato .002 .963 Not significant farmer field school participant 3. Number of farmers planting in lines/ using improved storage are you a Not 2.806 .101 cassava/potato farmer field school significant participant 4. Number of Farmers Adopting Spacing Not Are You a Cassava/Potato Farmer Field 1.321 .256 significant School Participant 5. Number of farmers adopting disease Highly control measures * are you a cassava/ 11.402 .001 significant potato farmer field school participant? 6. Number of farmers adopting pest con- Highly trol measures * are you a cassava/potato 24.851 000 significant farmer field school participant? 7. Total number of tertiary/processing Not groups formed in 2003 are you a cassava/ .141 .709 significant potato farmer field school participant? 8. Total number of groups assisted for Not support in 2003 * are you a cassava/ .703 .406 significant potato farmer field school participant? AEAs who participated in FFS were highly rated performing better in 2003 than previously, as compared to their counterparts who did not participate in FFS.

SUMMARY, CONCLUSIONS implementation of the pooled-training AND RECOMMENDATIONS programme for AEAs in districts in RTIP organized three training of which RTIP was operating. The RTTs trainers’ sessions for RTTs prior to the then trained AEAs in all the districts with The Effect of Training on Extension Delivery and Performance 161

a view to mainstreaming the knowledge programme by rating them as useful or and skills. The content of the RTIP very useful. Comparatively however, pooled-training programme consisted monitoring and evaluation as subject of: Principles and concepts of PRA; matter was the highest rated as not useful PRA tools and techniques; Fieldwork and also the least rated as useful or very or Field practice sessions; Gender useful. Similarly, almost 70% or more issues; Group formation; Effective of the trainees rated the subject matter communication; and Monitoring and areas, with the exception of monitoring evaluation.Reaction of trainee AEAs to and evaluation, as being quite or very pooled-training programme much applied in their work. Trainee AEAs had a high Monitoring and evaluation assessment of the competence of their (M&E) was the least rated by trainees trainers (RTTs), with more than 80% of as being quite or very much applied the trainees rating them as competent in their work. As much as 46% of the or very competent. Similarly, majority respondents rated M&E as not being of the trainees rated the teaching and applied much in their work or okay. facilitation methods and the practice The ensuing behaviours and attitudes sessions used in the pooled-training emanating from this was the poor programme as effective in promoting knowledge and skills in monitoring and learning. More than 50% of the evaluation, which was reflected in the trainees in each case assessed both the complete lack of basic monitoring data facilities and the general management expected from AEAs in the field. This of the training programme as adequate. lack of appreciation of the usefulness However, up to 70% of the respondents and application of M&E as a subject rated the duration of the pooled-training matter area could be attributed to the programme (2 days on average) as unplanned manner in which it was somehow adequate or inadequate for handled in the TOT workshops and the the content that was to be covered. subsequent poor handling by trainers during the pooled training programme Effect of RTIP training on for AEAs. AEA behaviour and KASA Eighty-three percent (83%) of changes, and performance farmer respondents belonged to farmer More than half the respondents showed groups, with over 83% of the members a positive attitude to all the subject joining in the last five years coinciding matter areas covered in the training with the period of RTIP implementation. 162 The Effect of Training on Extension Delivery and Performance

Sixty-nine percent of (69%) of all these Comparative effect of RTIP farmer groups were initiated by AEAs. training on AEAs behaviour, Majority (60%) of the farmers thought KASA changes, and that the performance of their AEAs in performance under normal 2003 was much better than before, 30% extension delivery and FFS thought it was the same as before while This study established that differences only 7% thought the performances of in the number of farmers adopting their AEAs had become worse than cassava disease and pest control before. measures in the operational areas of Farmers’ assessments of the AEA FFS participants on the one regularity of AEA visits under the hand and non-participants on the other normal extension delivery system were highly significant. Farmers in the were very low. Thirty percent (30%) operational areas of FFS-participating or less of the respondents reported AEAs adopted cassava disease and being visited once in a fortnight, which pest control measures more than in the happened to be the most common. This operational areas of non-participating was followed in descending order by AEAs. weekly, monthly, quarterly, bi-annual, The study also found that and annual visits. being a farmer FFS graduate was not Sixty-five percent (65%) of the independent of the performance rating AEA respondents considered lack given to AEAs by farmers. AEAs of market demand for RTIP cassava who participated in FFS were rated as the most important constraint to more as better than before 2003 as the smooth implementation of RTIP compared to their counterparts who in their operational areas. Similarly, did not participate in FFS. Similarly, provision of adequate logistics to AEAs there was significant difference with for their work, and encouragement regard to AEA field visits as assessed and advice from AEAs through FFS, by FFS graduates and non-graduates. were identified as the most important FFS-graduate farmers recorded higher measures which, in their opinion, will numbers of field visits from their AEAs improve their performance in RTIP than non-graduates. implementation and the adoption The results, according to the of improved technologies by target farmers’ own assessments, also beneficiaries. indicate that FFS graduate farmers and non-participating farmers differed The Effect of Training on Extension Delivery and Performance 163

significantly in relation to several training programme, trainee AEAs had variables including farmer group very good reason to rate the duration membership, sex, increased production as inadequate. Similarly, considering of local varieties, decreased cost of the importance of competence in production, reduced incidence of subject matter knowledge, skill and diseases, increased profits from cassava practical know-how for successful FFS production, planting in lines, the type facilitation, the duration for training for of cassava variety planted in lines, FFS facilitation was also inadequate. social status of respondents, number This is of course, unless the criteria for of field days attended by respondents the selection of the AEAs for the pilot within the village and within the FFS facilitation training were based on operational area in year 2003, the possession of these competences. number of result demonstrations 2. Trainee AEAs assessed most of attended by respondents in year 2003, the subject matter content of the and the number of combined result and pooled training and training for FFS method demonstrations attended by facilitation as useful for their work and respondents in year 2003. applied much of the knowledge and Yield, an important extension skills gained in the training in their effectiveness indicator, was found work. However, the trainees assessed to differ between FFS graduates and monitoring and evaluation as not useful, non-graduates. Nurah and Ahiale and consequently was least applied (2004) established that FFS graduates in their work. This reflected in their consistently obtained higher yields attitudes towards M&E in particular in 2003 than their non-participating resulting in poor or no monitoring of counterparts in both local and improved simple extension indicators expected of varieties of cassava. AEAs.

Conclusions 3. In spite of the fact that attempts The following conclusions can be have been made in the past and are drawn from the major findings. still being made to encourage building 1. In general, trainee AEAs had positive and working with farmer groups under assessments of both the RTIP pooled- the normal extension delivery system, training programme and the training there is evidence that there has been a for the facilitation of FFS. However, tremendous increase in the number of considering the content of the pooled farmer groups and group membership 164 The Effect of Training on Extension Delivery and Performance

during the last five years coinciding with for RTIP cassava and lack of logistic the period of RTIP implementation, and support to AEAs. Similarly, the most that AEAs were the principal initiators important measure suggested by farmers of these farmer groups. Evidence of to improve their benefits from cassava the effect of RTIP training on this may production was offering assistance however be indirect. By farmers’ own in the marketing of RTIP cassava. assessments, AEA performance in 2003 Other factors mentioned by farmers (certainly after the RTIP pooled-training did include the issues of poundability and training for FFS facilitation) was and the perceived ability to store for better than before. longer periods attributed to some local 4. Evidence from this study suggests varieties of cassava. So long as the most that FFS graduates, as compared to popular use for cassava continues to be those who did not participate and were fufu, poundability will remain a critical presumed under the normal extension issue with farmers until a ready market delivery system rated AEAs involved is found for unpoundable varieties in FFS higher on most extension through the development of viable effectiveness indicators. It is therefore cassava products. This is because of the not surprising for AEAs to suggest importance of these interlinked (market encouragement and advice from AEAs demand, poundability, and perceived through the FFS approach as their most ability to store for longer periods) important measure to improve RTIP issues to household food security for implementation in their operational resource poor farmers who happen to areas. The FFS approach assures them be the main target beneficiaries of RTIP. of the logistics required to carry out the work, thus solving a major constraint Recommendations (of lack of logistic support to AEAs) The following recommendations can experienced under the normal extension be made in respect of the findings and delivery system. conclusions of this study: 5. To improve the performance of 1. There is the need to review the AEAs in RTIP implementation and the training of trainers’ programme for adoption of improved technologies by the RTTs in M&E and subsequently target beneficiaries, the most important to organise training for all AEAs with constraints mentioned by the majority a view to mainstreaming it into the of AEAs were lack of market demand normal extension delivery system since evidence suggests that, by their The Effect of Training on Extension Delivery and Performance 165

own admission, the majority of AEAs adoption of improved technologies by do not only lack appreciation of the target beneficiaries, the most important usefulness of M&E, but have also failed constraint mentioned by the majority to apply it to their work. To this end, the of AEAs – lack of market demand for appointment of competent desk officers RTIP cassava – and conversely the at the district level with responsibility most important measure suggested by for guiding AEAs in the implementation farmers to improve their benefits from of all M&E activities to support the cassava production – offering assistance desk officer in establishing functional in the marketing of cassava – as well as management information systems. other constraints such as the provision This will go a long way to solving the of adequate logistics to AEAs for their problem of the lack of basic baseline work, and encouragement and advice information for proper agricultural from AEAs through the FFS approach – development planning. should be addressed. These constraints 2. Evidence from this study as well provided some of the bases for the Nurah and Ahiale (2004) suggests formulation and subsequent appraisal that the FFS approach to extension and implementation of the second delivery has had a better effect on the phase of root and tuber improvement performance of target beneficiaries on programme, which emphasised on several extension indicators than under marketing. the normal modified T&V extension 4. Finally, to further improve the delivery system. However, further adoption of improved technologies by studies may be necessary to establish the target beneficiaries, the reasons the apparent superiority of the pilot given by farmers for the choice of FFS approach as assessed by farmers cassava varieties – market demand, and AEAs. Cost-benefit analyses poundability, ability to store for longer and constraints to mainstreaming the periods in the ground – should be taken approach into the normal extension into consideration when researchers are delivery system could be a good starting developing new varieties, by making point. farmers active and equal partners in the 3. To improve the performance of technology development process. AEAs in RTIP implementation and the 166 The Effect of Training on Extension Delivery and Performance

REFERENCES

Bailey, K.D., (1987). Methods of social research (3rd Ed). New York: Free Press. Casely, D.J. & Lury, D.A., (1982). Monitoring and evaluation of agriculture and rural development projects. Baltimore and London: john Hopkins University Press (published for the World Bank) Misra, D.C. (1997). Monitoring extension programmes and resources. In E. B. Swanson, A. J. Sofranko, R. P. Bentz (Eds.), Improving agricultural extension, a reference manual (p. 151-160). FAO, Rome. Nurah, G.K., & Ahiale, D. (2004). Assessment of the economic sustainability of improved Cassava and Sweet potato tertiary planting material (MOFA-RTIP Evaluation Studies Report No. 3, Dept. of Agricultural Economics and Farm Management, KNUST, Kumasi). 167

An Evaluation of the Cassava Value Chain in Ghana

Gifty Boakye Appiah1, Robert Aidoo1, Kwasi Ohene-Yankyera1, Olav Jull Sorenson2 1Department of Agricultural Economics, Agribusiness and Extension, KNUST, Ghana 2Department of Business Economics, Aalborg University, Denmark

Abstract upgrading. Business constraints were The study mapped out the main actors identified and ranked on a three-point along the cassava value chain with their Likert scale. The study used primary respective roles and activities/processes. data from 600 actors (300 producers, It also identified the pressing business 151 processors and 150 traders) who constraints that impede the smooth were drawn through a combination of operations of chain actors. The mapping simple random and snowball sampling was done using a flow chart to establish techniques. The dominant type of the linkages that exist along the chain, governance structure along the cassava the flow of products and information value chain was found to be buyer- along the chain, governance structure as driven with processors acting as the well as supporting services and external lead firms and exerting higher degree influences that impact on the overall of influence and control in the chain. performance of the chain. The Foreign The major constraints to cassava Investment Advisory Service (FIAS) of production were low produce price, the International Finance Corporation high cost of labour and limited amount (IFC) and United Nations Industrial of credit. Processors of cassava into Development Organization (UNIDO) gari have serious challenges with health framework for holistic diagnostics hazards associated with the traditional of agro-industrial value chains was processing technologies they adopt adapted for this study to understand and high labour requirements. Traders the interconnections and relationships of fresh cassava roots are constrained among chain actors in addition to by high transportation costs as a result the identification of entry points and of bad road networks, limited access opportunities for innovation and to credit and lack of adequate storage 168 An Evaluation of the Cassava Value Chain in Ghana

facilities. Efficient information flow than 1000mm (FAO, 2008). The crop among cassava value chain actors referred to as ‘‘Africa’s best kept secret’’ is expected to promote technology is relatively disease, drought and locust transfer, innovation and market growth. resistant and could be harvested at any Introduction of standards in the trading convenient time, usually between 8 of cassava and cassava-based products and 24months subsequent to planting. and adoption of improved cassava It therefore serves as the last option processing technologies would address of food crop in many countries and some of the identified bottlenecks to provides a protection against unforeseen ensure optimal functionality of the food shortages or famine (FAO, 2008; cassava value chain in Ghana. Meridian Institute, 2009). Nonetheless, the choice of late harvesting could Introduction mean an opportunity cost of trading the Cassava is a major staple in Ghana and quality and starch content of the root is presently becoming the principal for a much lower one. Once the cassava agricultural product and a primary root is unearthed, it has roughly, a two- food security crop in Africa (ISSER, day shelf life without treatment (ibid). 2005). It is a major root and tuber Cassava significantly constitutes crop and contributes about 22% to a major part of the diets of many Ghana’s agricultural GDP. The crop has Ghanaians with an estimated annual gradually shifted from a subsistence per capita consumption of 151.4 kg crop to one with a large commercial (FRI, 2012). It also accounts for up potential (FAO, 2008). The total world to 40% of daily food intake (kcal per utilization of cassava is projected to capita per day) and is a good source reach 275 million tonnes by the year of carbohydrate. Its leaves are of high 2020 (IFPRI, 2008). It is the most nutritional value and can be eaten as widely produced root and tuber crop, vegetables. In Ghana, cassava is mainly cultivated vastly in nearly all the agro- used for household consumption. About ecological zones of Ghana. The reason 85 percent of the production is eaten as being that it can survive on poor quality food (IITA, 2009) and its consumption soils, within latitudes 30° north and cuts across all ten administrative regions south of the equator with a pH from of the country (World Bank, 2010). The 4 to 9. It also fares well in areas with products obtained from cassava roots are temperatures between 18 and 25°C and mostly consumed domestically and the an annual rainfall of just 50mm to more rest are fed into industrial production. An Evaluation of the Cassava Value Chain in Ghana 169

Moreover, due to the bulkiness and 2001, as a means to transform cassava perishability of cassava and increases into a major economic growth pole in postharvest losses, it is usually traded (Kasalu-Coffin et al., 2005). However, in processed forms by traditional small the success of the PSI on cassava was scale enterprises. It also serves as an very minimal, if any, due to operational intermediate product for animal feed, and technical challenges. In the starch bioethanol and starch markets. and livestock feed industry, cassava also Due to the increasing demand presents a lot of market opportunities. for high quality products of processed This study was conducted to map cassava by urban dwellers and the the cassava value chain to unearth the increased acknowledgement of its sequence of sourcing and marketing diverse industrial potential, there has functions of the individual actors in been an increase in the commercial the chain, the stakeholders that are use of cassava (Jumah et al., 2006). involved in the chain and how and The opportunities in this sector have where they affect primary production, even become greater with increases processing and distribution. This would in the chances of technology change. expose weak links in the chain and There exist the demand for cassava consequently bring to light areas where in both food and non-food industries we can forge new or better relationships for high quality processed products of to improve the overall success and cassava at different end-user markets. competitiveness in the chain to ensure An example is the high demand for high poverty alleviation. It will also serve as quality cassava flour (HQCF) as well a guide for key stakeholders to redefine as increased production of industrial their roles in the cassava value chain for grade cassava glue for the ply wood efficiency. industry. A larger part of HQCF was The Concept of Commodity supplied to the food industry and about Value Chains one half to the plywood manufacturing Several authors in value chain studies sector (Kleih et al., 2013). Based on have come up with an array of the socio-economic significance of definitions in helping to understand the cassava, the concept and how to analyze commodity launched a special program called the value chains. Hopkins and Wallerstein “President’s Special Initiative (PSI) on (1994) defined value chain as a system Agribusiness” for starch production involving labour and production and processing for export in August 170 An Evaluation of the Cassava Value Chain in Ghana

processes with the end result being the to understand how the creation of value finished good. With this, a commodity is is achieved and shared among chain taken and the set of inputs and processes actors/players. However, Ivarsson and that culminate in the production and Alvstam (2005), defined value chains as movement of that commodity are a means through which new production traced. The definition by Hobbs et al. forms and technologies, organisational (2000), stresses on value chain as a structure, relationships and labour vertical chain of activities, relating it networks are identified. Van den Berg to a type of supply chain that focusses et al. (2008) also defines value chain on the activities of the firm, through from two perspectives; the broader production, processing, distribution sense and the narrow sense. The narrow and trading it to the final consumer sense states that value chain consists (i.e. the complete chain of activities of a range of activities within a single from ‘‘farm to fork’’). However, this firm which includes the formation definition has a limitation of ignoring and design stage within that specific how chain activities are organized and enterprise to produce a desired output. how they function. The chain is only An example is the processing stage perceived as a strategic network or the along the cassava value chain and the presence of links between a number of decision on the type of value to create, free and autonomous organizations in a and the production, distribution and supply chain with little attention paid to marketing activities after sales service. value creation and sharing. However, the broader sense states that According to Kaplinsky et al. it is the different array of actors across (2002), value chain is defined as the enterprises to move a raw material complete array of activities that are through the different stages of the chain essential to bring a product or service to the final trade of the product. from formation/design stage, through The framework adopted by the the different stages of production, study from UNIDO (2009) combines transformation and distribution to the perspectives of the definitions final consumer as well as the final outlined and explains value chains disposal after use. This adopts a holistic as a set of businesses, activities and approach to assess how actors operate relationships that are involved in or perform their chain activities, how creating a final product or service. The actors are affected by activities of creation of the final product or service others and supporting services and also requires gradually adding value to An Evaluation of the Cassava Value Chain in Ghana 171

products as they pass from one link or products get to the final consumer. At stage in the chain to the other. Value every operational stage, a link was can be added either in the form of drawn between the source of the major transforming the original form of the inputs used by an actor, the output and product, combining with other products, the receiver (customer) of the generated transporting, packaging or marketing product. until it gets to the final consumer. The first step in the value chain UNIDO (2009) noted further that value mapping was identification of primary chain development has stood out as the activities along the chain with their perfect methodology or approach for corresponding actors. Secondly, the developing industries in developing main supporting activities with their countries. actors were also identified and recorded. Thirdly the locations and markets of the Cassava Value Chain Mapping identified activities/actors were also In reality, value chain linkages tend to mapped to show the regions, districts be more complex with various activities and markets that deal in the various and connections spanning different end products. Fourthly, the governance geographical areas and have many relations, institutions and regulatory potential dimensions, both tangible frameworks that influence the activities and intangible which could be included of the actors were also noted and in the value chain map. However, no described qualitatively. Lastly, the ideal value chain map exist for all proportion of the value created by the situations. Thus, there is no such thing various actors and who takes what part as a comprehensive, all-encompassing or proportion of the created value were value chain map. Therefore, depending also evaluated. on the scope and objective of the value In the FIAS (2007) framework, chain analysis, the dimensions that value chain analysis is explained as the are to be mapped are chosen. These method for accounting and presenting could be the product flows, the actors the value that is created in a product or involved in the chain, costs and margins service as it is transformed from raw at different levels, and information flow, inputs to a final product consumed by among others. end users, using the source, make and The study adopted the framework deliver approach. by FIAS (2007), to map the core linkages Source denotes the method from the point of production until the of acquiring goods and services as 172 An Evaluation of the Cassava Value Chain in Ghana

requisite inputs in the main production production technology/knowledge used process of a particular product. and options for upgrading technology Make explains the procedure or expanding capacities. necessary to convert or transform the iii. End market and trade: it refers to the raw material or requisite input into a description of the nature of the demand completed product. This product could for the end products in light of their be sold directly to consumers or used as features and the consumer perspectives. an intermediate input in the next stage In addition, the practices of trade and of the production process. markets as well as the capacities and Deliver refers to a description of level of competition and standards are the transportation (handling, loading, also discussed. off-loading) of the finished/ completed iv. Governance and Linkages: the type product or service to the next stage of governance and key governors in of the production activity or the final the chain are stated. The coordinating consumer. activities among actors and the The initial mapping of the value options or upgrading opportunities chain was followed by a description or are also reported. In addition using situation analysis of the various segments the following indicators; Asymmetry of the chain using the indicators in the of information (Knowledge of how UNIDO framework on the ‘holistic much product sells in the international diagnostics of agro industrial value market), Dependency ( how much of chains’ (Hartwich and Kormawa 2009). the output goes to the main buyer, and The indicators include: how many buyers exist for a particular i. Sourcing of inputs and supplies: actor) and Power asymmetry (whether this involves a description of the actor is allowed by buyer to use own characteristics of the primary products, brand of products) the producers and the input providers v. Macro-economic and policy at the various segments of the chain. context: this refers to the institutions, In addition to that, the present infrastructure – related inefficiencies infrastructure and transport facilities as and policies governing and affecting well as the provision of other logistic the operations/activities in the cassava facilities and channels of information value chain and directly affects exchange are reported. productivity, competitiveness and ii. Production capacity and technology: overall performance. The trade regimes this explains the capacity of the as well as existing and functional An Evaluation of the Cassava Value Chain in Ghana 173

barriers for imports and exports are also to employ in the production process. discussed. It is usually more capital intensive and the producers play the leading role in Governance in Value Chains organising and directing the activities Governance, otherwise referred to as in the chain (Gibbon, 2010). The power relations, could be explained as buyer-driven chains on the other hand the formal and informal arrangements are more labour intensive and they between participants of a value chain. are connected to industries that are It incorporates complexities within the essential for international development chain, ranging from contracts between and also in agricultural industries. In actors to government regulatory these chains the buyers play the leading frameworks, to norms that are unwritten role in coordinating chain activities, but spell out the inclusion or exclusion thereby specifying the products and the of participants in a market as well as volumes to be produced. This usually defined barriers of entry (Humphrey and happens when the shelf life of the Schmitz, 2002). According to Kaplinsky product in question is very short and and Morris (2001), governance refers to losses are possible since producers are the process of organising coordinated unable to control the marketing of these activities to identify changing profitable products. opportunities in a value chain as well Nonetheless, some chains are as assigning roles to key players in the both producer and market driven even chain. Gereffi (1994) and Kaplinsky though Gibbon and Ponte (2005) argue and Morris (2001) however, made a that chain governance or dominance clear distinction between two types does not necessarily constitute value of value chain governance, namely, chains. To them, some chains show producer driven and buyer-driven very little or no governance at all. It is (market oriented) chains. Gereffi again possible to have different types (1994) explained the term ‘governance’ of governance structures in so far as to connote ‘coordination’ which he there are different types of interaction explained in the context of global between actors at different parts of the commodity value chains as vertically value chain. This means that multiple organising chain activities and roles of governance systems or structures are actors. In the producer driven chains, possible and they range from setting the key producers control and specify rules to monitoring performance and the product and the key technologies offering assistance to the weak actors 174 An Evaluation of the Cassava Value Chain in Ghana

along the chain (Humphrey and influenced by the governance structure. Schmitz, 2002). Value chains that show Reach alternatively measures how this type of governance usually result in widespread the governance is applied conflicting roles of the actors and poor for the firm to be competitive in terms producers are most of the time worse of pricing and information flow. off (MSPA, 2010). Power relations/ governance are very Humphrey and Schmitz (2002), essential in understanding how specific also introduced transaction cost analysis chain activities are protected from in value chain governance but stressed competition, how entry barriers are on the need to go further than markets created, and how equitable gains/risks and integrated firm hierarchies. Most are distributed. food and agribusiness industries have In analysing governance very complicated value chains that are structures, some critical factors are not well organised and coordinated considered, including; rules and especially in the upstream stages regulations for the operation of the (Bröring, 2010). Because of this, Gereffi value chain, the impact of rules on et al. (2005) introduced a perspective value chain participants, the dominant called ‘modularisation’ that was meant coordination arrangements and agents to reduce the complexities of the chain in the value chain and the power and transaction costs. This means a re- relations that exist in the chains. direction of the focus to specific markets Keare (2001), argues that the issue of (inter-firm links) and not the chain as governance can be considered as an a whole. The economic implication of innovation, in the sense that requisite governance as expounded by Gibbon skills are needed in choosing the right et al. (2008) and Bair (2005) is that type of participation and governance firms are required to choose the form framework to deal with pertinent and of governance that would minimise complicated policy problems in a more transaction costs especially when trust efficient way. Again, all actors have the is present among firms. distributional capacity to collaborate Value chain governance can also and contribute to solving policy and be explained by means of its ‘richness’ non-policy issues towards achieving a and ‘reach’ (Evans and Wurster, 2000). common goal even though they might The richness represents the gravity have conflicting interests. Therefore, or extent to which the main activities the condition for the existence of these of the chain actors are affected or governance frameworks is characterized An Evaluation of the Cassava Value Chain in Ghana 175

by “cooperative Infrastructure” and institutions to participatory approaches actor networking (Bourgon, 2011). This of experimental governance frameworks implies that there is the coordination of that are generated through the combined activities between firms with mutual actions of top-down approaches and interdependence (i.e. building of bottom-up approaches. Institution of strategic alliances). These collaborated governance structures would enhance and pool of efforts in building good the smooth flow of activities both relationships help to present some form in terms of product specification of flexibility in coping with expected and timely delivery. In addition to and unexpected changes (Jones, 2011). this, the risk that is associated with The success of the governance supplier failures in terms of quality and system would be significantly affected response time would be reduced. That by the extent to which every sector of notwithstanding, actors along the chain the chain would have a representation have the responsibility of ensuring that in the whole set of stakeholders that the relationships and networks that exist would be affected. This implies that, are not left to chance but rather, have for example, smallholder farmers in the a true reflection in the organization’s cassava value chain would have a voice objectives. That said, Humphrey and as well as the powerful actors in the Schmitz (2002) stressed that knowledge chain with well-organized capabilities. of the type of governance structure Information flow along the chain also helps in the identification of options for becomes smooth with well-defined upgrading, either in terms of process, network facilitators and intermediary product and or functional upgrading in and local institutions thereby reducing the commodity value chain. the problem of coordination and Upgrading in Value Chains persistent inequality. Doner et al. Kaplinsky et al. (2002) explains (2009) emphasized that well defined upgrading as an effort on the part of institutional roles and capabilities for actors to improve their products or different institutions and organizations move to other sectors of the chain as would have differences in their their way of being incorporated into development outcomes. Furthermore, local and global value chains so as to Kumar and Kant (2006) stressed on the maximize value creation and learning. importance to further investigate the Again, according to Kaplinsky and possible consequences of ‘institutional Morris (2001), upgrading denotes the resistance’ and domestic support 176 An Evaluation of the Cassava Value Chain in Ghana

attainment of technological capabilities Upgrading at different stages enhances as well as market linkages which chain competitiveness. Consequently, support firms to engage in higher- Barrientos et al. (2010), describes value activities to improve upon their economic upgrading as the process competiveness. However, upgrading whereby economic actors move from does not always require using high- low-value to relatively high-value industrialized technology. Conversely, activities in global production networks. even the absence of technology has In the agricultural sector, upgrading encouraged people to use available is vital particularly because most traditional methods and cultural commodities are highly perishable and practices to upgrade in their own low- found especially with root and tuber tech way. For example, the traditional crops and vegetables (Humphrey, 2003; means of processing cassava into gari in Humphrey and Memedovic, 2006). Ghana usually follows low-technology. There are various kinds of Upgrading can occur at various stages of upgrading strategies or indicators, the chain and it requires the continuous including; product upgrading, process changes in the selected competencies upgrading, functional upgrading, of firms. An examination of the process organizational upgrading and inter- of upgrading also takes account of sectoral upgrading (Gereffiet al., 2001). the valuation of the profitability of Product upgrading can be explained value chain actors in addition to the as the creation of new sophisticated description of constraints that actors products with enhanced quality and along the chain face. Governance higher value-added or improving old structures have a significant influence on products faster than competitors at the the kind of upgrading actors should be firm level (Barrientos et al., 2010). An engaged in and the environment within example is the processing of cassava which this is done is also influenced by into high quality cassava flour (HQCF), regulations and standards, as well as gari (cassava grits) or starch. Product trade restrictions and entry barriers. upgrading is becoming more and Economic upgrading deals more important as urban consumers with the availability of capital (i.e. demand high variety of value added and technology) and labour which requires convenient products. development of individual skills, Process upgrading is the process improvement in expertise, equipment of transforming the inputs or raw and positive working conditions. materials into value added products by An Evaluation of the Cassava Value Chain in Ghana 177

reorganizing the production system. Inter-sectoral upgrading is using the This involves increasing the efficiency knowledge acquired in a particular of internal processes in a way that would chain to move to another sector (Laven give a competitive edge over rivals and 2011, Trienekens 2011, Schmitz, 2004) also, improving the current production and the ability of the actors involved to technologies that would enhance create and control value. quality and volumes of products. This The upgrading strategies also can be done by investing in machinery, take into account the markets served utilization of new technologies and (low income, middle income and high innovation, public and private research income markets) as well as the policy and and development, the capacity to absorb institutional environment of the chains. new knowledge and organization Analysis of the upgrading strategies in of labour. An example of this is the the cassava value chain would help in adoption of Good Manufacturing understanding the types that exist and Practices (GMPs) in the processing of the activities, functions and forms of ‘gari’ by mechanical means under very products actors are engaged in to reveal good hygienic conditions (ibid). the possible avenues to enhance chain Functional upgrading involves taking competitiveness. on new core activities or changing the mix of activities and assuming different Methodology functions or moving to other areas in Sampling and Data Collection the chain. These include marketing, The study population was all key actors branding, designing, transportation, along the cassava value chain in Ghana. certification, standards and enhancing For producers in the cassava value chain, information flows, etc. An example a multi – stage sampling procedure is the re-branding of ‘gari’ and was used. The first stage involved the development of standards and purposively selecting three regions certification that would make it globally (Ashanti, Brong-Ahafo and Northern accepted. regions) due to the concentration of Organizational upgrading requires cassava value chain activities in the managing and improving the staff skills areas as well as the differences in and knowledge which could either be agro-ecological and socio-economic in terms of vocational training or firm- characteristics. In the second stage, two level training. districts/municipalities were selected from each region based on the levels 178 An Evaluation of the Cassava Value Chain in Ghana

of cassava production and the presence cassava processing activities. Within of ‘Good Practice’ cassava processing each community, simple random Centers (GPCs). For Ashanti Region, sampling technique was employed to Mampong municipality and Sekyere select the producers of cassava. A list Central district were selected; for of cassava producers was obtained Brong Ahafo region, Techiman from the district office of the Ministry municipality and Wenchi district were of Food and Agriculture (MoFA) from selected and for Northern region, East which the sample was drawn based on Gonja and West Gonja Districts were the proportion of cassava producers in selected for the survey. The third the communities. The numbers drawn stage involved purposively selecting from each community are presented in three communities from each district Table 1. based on the levels of production and Table 1: Sample of Cassava Producers drawn from Region/District/Community District/ Region Community Population Sample Size Municipal Adidwan 180 18 Mampong Krobo 171 17 Kyirimfaso 145 15 Ashanti Achiase 82 20 Sekyere Atonsu 70 17 Central Nsuta 51 13 Aworopata 597 25 Techiman Aworowa 78 4 Oforikrom 501 21 Brong Ahafo Amponsakrom 345 22 Wenchi Subinso No.2 120 8 Wurompo 332 20 Lamsa 184 14 East Gonja Makango 148 11 Sisipe 346 25 Northern Nobori 219 35 West Gonja Agric 38 6 Sore 53 9 Total - - 3,660 300 The snowballing technique was adopted to select the processors and traders in the chain based on referrals An Evaluation of the Cassava Value Chain in Ghana 179 from initial subjects (producers). processors and traders drawn from the Tables 2 and 3 present the sample of communities respectively. Table 2: Sample of Cassava Processors drawn from Region/District/Community Region District/Municipal Community Sample Size Krobo 37 Mampong 3 Mampong Kyirimfaso 1 Ashanti Old Daamang 1 Woraso 1 Atonsu 8 Sekyere Central Nsuta 1 Aworowa 10 Asueyi 3 Techiman Hansua 5 Nkwaeso 6 Brong Ahafo Amponsakrom 10 Akrofrom 3 Wenchi Subinso No.1 1 Subinso No.2 8 Awojakope 17 Lamsa 3 East Gonja Sisipe 6 Makango 1 Salaga 1 Northern Canteen 9 Agric 2 Abingakuraa 3 West Gonja Hangaline 6 Jiranzanaa 4 Damongo 1 Total - - 151 180 An Evaluation of the Cassava Value Chain in Ghana

Table 3: Sample of Cassava Traders drawn from Region/District/Markets Region District/Municipal Community/market Sample Size Mampong Mampong Market 15 Ashanti Ejura Sekyedumasi Ejura Market 35 Techiman Techiman Market 35 Brong Ahafo Wenchi Wenchi Market 15 Sisipe 16 East Gonja Salaga 5 Lamsa 3 Northern Damongo 12 West Gonja Abingakuraa 9 Hangaline 5 Total - - 150 Finally, a census of all ten (10) functional names and locations of the GPCs are Good Practice Centers (GPC’s) in provided in Table 4 below. the three regions was conducted. The Table 4: Existing and Functional GPCs in the Study Area

DISTRICT/ No NAME LOCATION REGION MUNICIPALITY Josma Agro-Industries 1 Woraso Mampong Ashanti Ltd. Dukukrom Cassava Pro- 2 Adidwan Mampong Ashanti cessing Center Christaa Agric 3 Old Daamang Mampong Ashanti Ventures Aworowa Cassava 4 Techiman Techiman Brong Ahafo Processing Society Hansua Women Gari 5 Hansua Techiman Brong Ahafo Society Asuogya Agro 6 Asueyi Techiman Brong Ahafo processing Northern Women 7 Wenchi Wenchi Brong Ahafo Processing Group Kanyitiwele II Cassava 8 Damongo West Gonja Northern Processing Group Salaga Cassava 9 Salaga East Gonja Northern Processing Center Miwoenenyo 10 Makango East Gonja Northern Cassava Processors Before the actual data collection was involved informal discussions with key done, a pre-survey was conducted, which stakeholders in the cassava value chain An Evaluation of the Cassava Value Chain in Ghana 181

to gain some insights into value chain governance within the chains, quality activities, policies and institutional and frequency of interaction and framework as well as the supporting information flow, and the role of services, and governance arrangements. policy in the functionality of the chain. Again, generalinformation on habits Quantitative data for measures of costs and practices or operations of cassava and margins were gathered through producers, processors and traders were face-to-face personal interviews using sourced to aid in the design of the data the structured questionnaire. In all collection instruments. The selected study locations, local language was communities in the Ashanti region used in questionnaire administration were used for the pre-testing exercise and focus group discussions to ensure where 20 respondents in total were high response rate and quality data. considered (10 producers, 5 processors Data Analysis and 5 traders). The revised structured Identification of actors and questionnaire and interviewer guides for Mapping of the Chain different chain actors were used to elicit The study adopted the framework by primary data for the respondents. The FIAS (2007) to map the core linkages interviewer guides or checklists were from the point of production until the employed to conduct key informant products get to the final consumer. At interviews and focus group discussions. every operational stage, a link was drawn Focus groups comprised five (5) to 12 between the sources of the major inputs actors at similar nodes of the cassava used by an actor to produce the output value chain. Data for the value chain through the various intermediaries to mapping were obtained from qualitative the final receiver (customer) of the key informant interviews, observations generated product. and focus group discussions with The first step in the value chain producers, processors and traders. The mapping was identification of primary key informants included agricultural activities along the chain with their extension staff, chairpersons of corresponding actors. Secondly, the associations, and cassava market main supporting activities with their queens. The key informant interviews actors were also identified and recorded. and focus group discussions were done Thirdly the locations and markets of the to ascertain and understand the value identified activities/actors were also chain structure, roles of actors and the mapped to show the regions, districts prevailing conditions and practices, 182 An Evaluation of the Cassava Value Chain in Ghana

and markets that deal in the various the actor has paid for acquiring inputs end products. Fourthly, the governance from the preceding stage of the chain as relations, institutions and regulatory well as the intermediate goods bought framework that influences the activities and the supply of inputs and services of the actors were also noted and from actors who are not necessarily described qualitatively. Lastly, the regarded as part of the chain. That is proportion of the value created by the to say, value addition is the difference various actors and who takes what part between the price a value chain actor or proportion of the created value were pays for a product and the price he sells also evaluated. it for (GTZ, 2007). Different actors add different value and therefore incur Estimation of Costs, Margins, different costs. The costs and revenues Value Added, and Returns generated are used to estimate the value The estimation of value addition uses added. a technique that considers all aspects In analysing the costs, two main of an existing product or commodity components (fixed cost and the variable and determines the minimum cost costs) were considered. The fixed cost necessary for the requirements to component does not change with the perform a specific function in its level/size of production. It is usually production (Lal, 2007). Furthermore, obtained as the sum of the various value addition focusses on the essential depreciated fixed cost items of each characteristics of a product desirable actor. In cases where there is a shared by a customer and identifies the most use of a fixed cost item by several economical means of producing it by enterprises, the fixed cost associated getting a balance between the quality with the item is split depending on the and cost of the product. Albu and Al proportion or extent of usage among Griffith (2005) explain that the value the enterprises. The total fixed cost is addition in a chain is equivalent to the expressed as: total value (final sales price * volume (1) n sold) generated by chain operators minus the cost incurred in producing that TFC= FCi åi 1 volume of product. In other words, the = value added per unit of a product is the Where TFC is the total depreciated difference between the price obtained fixed cost and FC is depreciated by the value chain actor and the price i fixed cost of the ith item. Depreciation An Evaluation of the Cassava Value Chain in Ghana 183

was calculated using the straight line Where TVC is the total variable th method and it is expressed as: cost and ri ­ is the unit price of the i

variable cost item and xi­­ is the quantity Oc of the ith item used. c = The total variable cost per unit n of output (TVC/unit) is obtained by (2) dividing the total variable cost by the Where Dc is the depreciated cost, Oc output (kg) and it is given as: is the original cost of the fixed item (5) n and n is the number of years of useful VCi life.The total fixed cost per unit of the TVC/ unit = å Qi output is obtained by dividing the total i=1 depreciated fixed costs by output (kg),

given as: Where, VCi is the variable cost

associated with variable factor i and Qi n is the output. FCi TFC/ unit = The total cost per unit is therefore å Qi i=1 estimated as the sum of the total (3) variable cost (TVC) and the total fixed Where TFC/unit is the total fixed cost (TFC), expressed as: cost per unit of output (kg), FC is the TC/// unit= TFC unit + TVC unit depreciated fixed cost and Q is the (6) output. Estimation of the total revenue is The variable cost component is done by multiplying the total quantity made up of costs that change directly (output) or quantity sold by the with the level of production in a given prevailing market price and summing production or sales cycle. Total Variable them up. This is given as: Cost (TVC) was obtained by using the (7) equation: (4) n n TR= pci q TVC= rii x å å i=1 i=1 184 An Evaluation of the Cassava Value Chain in Ghana

Where TR is total revenue, pc is the price is the total cost and Cp is the value/

per unit and qi is the quantity produced cost of the commodity in process/raw or handled. material. The average value added for The profits obtained by various the various categories of actors is again actors in the chain were estimated as the defined as the ratio of the value added to difference between the price or value of the various sample sizes (n), expressed the actor’s output and the cost incurred as: in producing that output. Therefore, (10) profit or net income (NI) was estimated VA by deducting the total cost (both variable MeanVA = and fixed costs) from the total revenue. n This was expressed as: Where meanVA is the average (8) value added per unit, VA is value added per unit and n is the sample size. π=TR-TC Return on investment is a flexible Where π is profit, TR is total revenue and simple tool used as a performance and TC is total cost. measure to assess and compare the The profit obtained per unit of a profitability of a number of investments. product is also estimated by dividing It estimates the returns or benefits the total profit of an actor by the total (margins or profit) from an investment quantity of products sold comparative to the investment’s cost The actual economic value-added (returns divided by cost of investment) is captured as the difference between and the result is usually expressed as the total cost incurred in producing a a percentage or ratio. The percentage unit of output and the cost of the raw term allows for ease of comparison of material on which the value was added different types of investments. Positive (known as the commodity in process). and higher values of ROI are preferred. The commodity in process is defined ROI per every cedi invested was as the raw material at the beginning expressed as: of every stage. The value added is (11) therefore given as: (9) RO =πp VA=TC-Cp Tc Where VA is the value added, TC Where π is profit and Tc is cost An Evaluation of the Cassava Value Chain in Ghana 185

of investment. Demographic Characteristics of Actors along the Cassava Value Chain Constraints analysis The demographic characteristics The business constraints were identified of actors in the cassava value chain and presented to respondents to rank are expressed in Table 5. The average on a three-point Likert scale (1=Agree, age of cassava producers is 47 years, 2=Neutral and 3=Disagree). The mean processors and traders are around 42 rank for each of the listed constraints years and the mean age for all primary was computed to aid in arranging the actors operating along the cassava value constraints in order of priority. Simple chain is 44 years. This lies within the tables were used to display the key economically active bracket of between constraints faced by different actors in 25 and 59 years. However, the energetic the cassava value chain and Kendal’s and active youth of between 25 and 40 coefficient of concordance (w) was years are largely missing in the chain. computed to measure the degree of This also indicates that actors all things agreement among the actors with being equal, have been able to gather respect to constraints ranking. some experience on their operations Results and Discussion and are therefore expected to improve upon their productive performances. Table 5: Demographic Characteristics of Actors along the Cassava Value Chain Producers Processors Traders All Actors Variable N=300 N=151 N =150 N=601 Mean Std. Mean Std. Mean Std. Mean Std. Age 46.9 14.5 42.1 12.2 41.6 10.5 44.4*** 13.2 Sex 0.773 0.419 0.119 0.325 0.013 0.115 0.419*** 0.494 Education 5.5 5.4 5.3 5.2 5.0 5.1 5.3 5.3 Household 7.2 4.0 7.5 4.3 6.4 2.6 7.1** 3.8 size Experience 16.5 12.4 10.8 8.6 11.2 9.3 13.7*** 11.1 Credit 54.8 210.9 56.5 220.6 166.9 526.5 83.2*** 324.8 186 An Evaluation of the Cassava Value Chain in Ghana

Mapping of the Cassava products, services and core linkages Value Chain along the cassava value chain are Results from the study revealed that the shown in Fig 1. This map shows the cassava chain has undergone flow of goods and services as cassava several developments over the and cassava based products are moved years to produce diverse channels for from producers to customers as well as various activities and processes by sequence of intermediaries and linkages several actors. The main activities, among the various actors.

Fig 1: The Cassava Value Chain

Source: Author’s construct based on survey data, 2015. An Evaluation of the Cassava Value Chain in Ghana 187

The main activities in the cassava value dried chips and flour value chains. chain include the supply of inputs, The starch and bio-ethanol industries production of raw tubers, processing lack the needed capacity, market and of raw tubers into desirable forms and expertise to produce. Technical advice the distribution (trading) of the desired and training were mostly provided cassava based products to the final by MOFA under the Root and Tuber consumer. The main varieties produced Improvement and Marketing Program are Dabo, Effisiafi and Garibankye. (RTIMP). Trainings largely focused on Dabo is a local variety and it is preferred the best agronomic practices to adopt on for its poundability and fluffiness their farms and processing techniques especially when produce are to be sold for improved yield, efficiency and in their fresh state and it is usually productivity. Occasional assistance used for preparing fufu and other local came from some financial institutions dishes. Effisiafi and Gari bankye are who supported actors with credit at high improved varieties mostly preferred interest rate of about 35% to enhance for processing because of their high dry their operations. The Food and Drug matter content, high yielding and early Authority (FDA) also intermittently maturing characteristics. The linkages visited processors to ensure that some identified and mapped revealed that basic food safety standards, product the markets within which most trading quality specifications, phytosanitary activities are performed included the control measures as well as issues of Mampong and Ejura markets in the certification are adhered to. Export of Ashanti Region, Techiman and Wenchi cassava products from Ghana however markets in the Brong Ahafo Region and is low since actors are unable to meet Sisipe, Damongo, Salaga, Abingakura, the volumes and required standards for Lamsa and Hangaline markets in the trading on the international markets. At Northern Region. every stage of the chain, economic value In addition to the production is added, be it form, time and/ or place and marketing of fresh tubers, about (distribution), which are measured in seven different cassava chains were terms of the cost incurred in adding that identified. These include gari, High particular value. quality cassava flour, starch, dried In the food industry, cassava is chips, bioethanol, animal feed and processed mainly into cassava grits, cassava used in non-food industries. commonly known as gari, cassava Most common among these were gari, pellets (kokonte), cassava flour, cassava 188 An Evaluation of the Cassava Value Chain in Ghana

dough (agbelima) and starch. Some of locally with only 5% being traded in the the traditional meals prepared from international market. cassava are fufu, banku, akple, yaka yaka, Sourcing of Inputs agbeli kakro, akyeke etc. Processing of and Supplies cassava ranges from simple boiling, The first stage in the chain is the sourcing drying and roasting of the roots to and acquisition of inputs, which fermentation of the products as well as include cassava cuttings, herbicides, the production of alcohol for beverages machinery services and credit. The and extraction of starches. Gari is the main source of the cassava cuttings most well defined product of cassava (planting materials) were from farmers’ in terms of standards and market. In own farms and farms of friends and the paperboard and plywood industry, relatives. Occasionally, farmers were cassava is used to produce glue, veneer able to source planting materials from adhesives and other binding materials. the Ministry of Food and Agriculture In addition to that, it is used to produce at a cost but was mostly unavailable. eco-friendly and recyclable plastics Herbicides were acquired from various and textiles. Moreover, it is used in agro chemical shops available in the the pharmaceutical industry to derive producing area and urban markets glucose and dextrin from cassava for and machinery services, especially syrups. The leaves, peels, dried chips for ploughing, from individual owners and pellets are also used as animal feed of tractors in the respective districts. in the livestock industry (Dziedzoave Producers mainly used their own equity et al., 2002). The peels are also used funds for financing production activities as substrate in the production of with a few “privileged” ones sourcing mushrooms. About 20% of losses are some amount from financial institutions recorded when raw tubers are moved under cumbersome procedures and from the production node of the chain high interest rates. to the processing node and 30% lost Processors mainly get supplies through the movement of raw tubers from small scale farmers and they from the production stage to the trading inform the farmers on the kind of stage. About 65% of the supplies of raw varieties they should produce to fit their cassava enters the processing node of various processing activities. Bigger the chain and the remaining 35% goes firms, especially those who operate to the local market. A huge proportion of under the good practice technology 95% of processed cassava is consumed An Evaluation of the Cassava Value Chain in Ghana 189

(GPC), however integrate backwards operations. to produce and use their own supplies. Production Capacity This they believe guarantees timely and Technology and reliable supply of raw materials for From the study results, cassava their processing activities. production is dominated by smallholders Traders of the processed products with an average farm size of 1.42ha usually move to the processing sites to (3.51 acres). These are indigenous get supplies for the market. However, inhabitants who either operate their own processors (who use the traditional farmlands or rent land in the production means and hence have limited capacity) season. Farmers practice either mixed usually double as traders and take their cropping, where they plant other crops own products to the market. Traders such as groundnut, maize, beans etc. who deal with fresh tubers usually on the same piece of land or mono – buy directly at the farm gate or have cropping where cassava is cultivated some informal arrangements with alone. The crop is either planted on a farmers to harvest and bring produce level ground or in mounds which is to the market the same day since it believed to make harvesting easier is highly perishable. However, roads thereby recovering most of the produce. to most farms are poor in nature and From the study results, majority of farmers who are constrained by these producers in the Brong Ahafo region inaccessible and bad roads often (95%) and Northern region (84%) practice spot marketing and therefore plant in mounds. However, those in stand the chance of recording high the Ashanti region mainly plant on the losses in the event of limited or no level ground. Small scale producers buyers. Roads from processing sites as indicated by Kaplinsky and Morris to market are generally tarred and the (2001), can enhance their operations use of the tricycle (aboboyaa) is the by adopting the simple techniques of main means of transportation for actors good practices (process upgrading) along the chain. Information exchange to improve yields and consequently along the chain is generally asymmetric expand their acreages to realise the full and this breeds mistrust among actors. benefits of cassava production. Those who nevertheless belong to The study results show that some associations/ organisations share processors who use traditional and information on mainly produce prices labour intensive technologies have the and new technologies to enhance their 190 An Evaluation of the Cassava Value Chain in Ghana

capacity to process 278kg of gari per between cassava traders and actors every processing cycle for four cycles outside the country even though some in a week; but they are only able to traders and processors believe their process 212kg per cycle. However, produce/products can be found on those operating under the good practice the international market (information technology have the capacity to process asymmetry). It was reported that 490 kg of gari per every processing some itinerant traders buy gari from cycle and are able to process 470kg. processors and rebrand for the export More processors in the Northern market. This presents an opportunity for region (46%) operate under the GPC the processing and marketing segments technology and in groups as compared to expand their operations and penetrate to those in the Ashanti (32%) and Brong the international market through proper Ahafo Region (36%). Even though certification which hitherto has proven the good practice system produces very difficult. about 122% more than the traditional The traders along the cassava value operators, both systems have deficits chain usually have informal and verbal and the inability to process to capacity contracts with farmers and processors is because of the inadequacy of raw that spell out the responsibilities of materials due to poor linkages between both parties in terms of time of delivery, producers and processors. This brings prices and payment terms. to light the fact that the attainment of The study results also showed technological capabilities (process that actors along the cassava chain upgrading) as well as market linkages have different cost streams due to the will support actors to process higher- differences in the type of value added value products (product upgrading) to and the end product of interest. The value improve upon their competitiveness as added, measured as the cost incurred noted by Kaplinsky et al. (2002). in adding value to the commodity in The marketing segment of process showed that processors add the the chain comprises wholesalers, most value to cassava with a proportion constituting about 12.6%, retailers of 76.4%, followed by producers with of raw/fresh tubers, dominating with a percentage of 17.2%. Traders add 58%, retailers of processed products, the least value to cassava in terms 28% and produce assemblers/itinerant of distribution or place value with a traders with a proportion of 1.3%. proportion of about 6.3%. There is no established export linkage An Evaluation of the Cassava Value Chain in Ghana 191

End Market and trade poor harvesting techniques. However, Cassava is demanded both in its raw farmers lose about 30% when sold to and processed forms based on its use, retailers and produce assemblers due features and consumer characteristics to untimely delivery and poor access and perspectives. In the Ashanti region, routes to farmlands. Nearly 95% of the sale of raw tubers for the preparation processed products goes to the local of fufu is very common since it is the market and patronised majorly by main dish among the Ashantis. The second cycle schools and schools poundability and fluffiness features of under the government school feeding the preferred variety (dabo) perfectly program (50%), retailers (30%) and suits this purpose. The Brong Ahafo wholesalers (15%). The remaining 5% region has a fair blend of the sale of is picked by assemblers for the export raw tubers and gari. Even though fufu market, particulary, EU, Asia and USA. is also a delicacy, it is not as common Standard units are used in the sale of as seen in the Ashanti region. However, processed products (gari) in the form the main product from cassava found in of Olonka (2.5 kg), pan which makes the northern region is the cassava chips, 15 olonka (37.5kg), No.4 bag (120kg) which is dried and stored. The chips are and No.5 bag (150kg). Fresh tubers are further milled into powder form and however sold in bags and tricycles or used for the preparation of kokonte and sometimes whole farmland to traders to porridge. Processing of cassava into harvest. There is therefore no standard gari in the Northern region became measurement and traders sell in the intense with the introduction of the GPC local markets based on the cost of the technology by RTIMP. About 65.3% of produce, margins expected and by their the produce sold goes to processors and own discretion. the remaining enters the local market Governance and Linkages to be sold in their raw state by mainly The performance of the cassava retailers and produce assemblers to value chain requires that actors perform individual consumers, restaurants, specific roles for its enhancement schools etc. About 20% of losses are (Esegbey, 2009). Some actors however recorded when produce are sold to exert enormous level of influence on processors. This is because processors the activities and operations of other make their own arrangements for actors along the chain. The cassava harvesting and transportation and the chain is buyer – driven and decisions losses are due to bruises as a result of 192 An Evaluation of the Cassava Value Chain in Ghana

lie with the processors and traders who processors however, have been able to are considered as key governors of the establish informal linkages with others chain. The governors facilitate and make to be informed about prices and markets decisions on the variety to produce, time via mobile phones to reduce losses and of harvesting, time of delivery, quality ensure continuity of their operations. characteristics expected, technology In addition, actors who belong to required, pricing, access to markets some form of associations gain some and mode of delivery among others. power to bargain. This is however not In addition to that, there are several patronized by actors in all three zones. functions of these actors including About 27% of producers in the Ashanti chain organization, information region belong to associations with dissemination and protection from 15% and 48% in the Brong Ahafo and competition that enhance the creation Northern Regions respectively. Trader and transfer of products from one node associations are more popular in the of the chain to the other until they reach Northern Region with a proportion of the final consumer. Nonetheless, the 52% joining. Processor associations are chain is characterized by information however largely missing in all zones. and power asymmetry and producers Costs, Returns and value addition are largely unaware of how much their along the Cassava value chain produce are sold for locally or their Actors along the cassava chain worth on the international market. have different cost streams due to the Due to the slow and improper flow of differences in the type of value added information, producers especially are and the end product of interest. Table left with very little or no bargaining 6 shows the costs incurred in adding power and they most often than not sell value, the revenues accrued per each their produce at very low prices. The actor, the value added as a measure of nature of the governance structure in the the cost incurred in adding value to the chain is that of ‘captive’ inferring that commodity in process and the returns producers usually have low capabilities on the investment of each actor. This and their operations are dependent gives an overview of which of the on dominant buyers (processors and main activities along the chain is more traders) who mostly exert high degree profitable in the light of the prevailing of influence and control (Gereffi et al., circumstances. 2005). Some producers and small scale An Evaluation of the Cassava Value Chain in Ghana 193 Kg ROI/ 0.0032 0.0012 0.0013 (%) 81.8 51.1 32.0 ROI Kg VA/ 0.12 0.54 0.05 Value 2314.1 1925.2 Added 19246.5 Kg 0.03 0.29 0.14 Profit/ NI Profit/ 1363.26 6482.77 17895.54 TR 3769.1 61477.8 30382.6 TC 2405.90 43582.2 23899.8 TVC 2296.65 43381.35 23853.46 TFC 46.33 109.25 200.88 Producers Processors Traders Actors Table 6: Profits, Value Addition and Returns on Investment for actors in the Cassava value chains (GH¢) Value 6: Profits, Table 194 An Evaluation of the Cassava Value Chain in Ghana

For ease of comparisons across the of GH¢6,482.77 and revenue of 25.2%. links, computations were made per Only about 6.5% of the profit per unit unit kg of the products. Processors of kg accrues to producers with an annual cassava incurred the highest total cost net income of GH¢3,769.1. In terms of of 62.4%, followed by traders with value addition activities along the chain, a percentage of 34.2%. Producers processors are again seen as the actors incurred the lowest cost of 3.4% that add the most value to cassava with indicating that of all the main activities a percentage of 76.1%, followed by along the chain, production of cassava producers with a percentage of 16.9%. is the easiest to enter since it requires Traders add the least value to cassava in the minimum cost as a start-up. The terms of distribution or space value with reverse is true for cassava processing a percentage of about 7%. Conversely, however, processing yields the highest producers have an 81.8% on their revenue of about 69.5% with an returns on investment since they incur annual net income of GH¢17,895.54 the lowest costs. Processors and traders and GH¢0.29 profit on every kg of have 51.1% and 32% of returns on their cassava processed. This amounts to a investments respectively.Based on proportion of 63% on the profit per kg all the indicators discussed above, achieved by the actors. This is followed cassava processing is more lucrative by the traders with a proportion of and competitive with the highest 30.4% on the proportion of profit per contribution to producing higher kg accrued with an annual net income quality value added products in the cassava chain. An Evaluation of the Cassava Value Chain in Ghana 195

Figure 2 : Value Addition per Kg of Cassava Along the Chain

Macro-economic and This policy saves the nation about 127 Policy Context billion Naira yearly and encourages In Ghana, the main institution the production of cassava, thereby responsible for cassava production and creating jobs and building domestic its related activities is the Ministry of wealth (Adesina, 2014). The trading of Food and Agriculture which is mostly cassava and cassava based products is constrained by inadequate logistics for done sparingly and informally on the effective discharge of its duties. Again, international market due to the low/ the ratio of an extension officer to famer varying quality of products and the lack is 1:1500 (MOFA, 2012). This limits of price competitiveness as reported by the number of contacts in a production Rees (2012). season for effective dissemination of The study results also revealed information and assistance. that the certification process for the Moreover, policies governing the release of new varieties is rather use of cassava and cassava products slow and impedes on the smooth and as alternatives for other imported timely distribution of cassava cuttings cereals are largely absent. In Nigeria to farmers to enhance yields. This for instance there is a policy on the result could contribute and somewhat use of about 20% of high quality confirms the report by IITA, 2009 that cassava flour in their baking industry. producers rely mainly on cuttings from 196 An Evaluation of the Cassava Value Chain in Ghana

their farms. In addition to that due to the and the differences in characteristics limited number of extension officers, are as a result of differences in resource ensuring that producers practice the endowments, managerial and technical whole package with the released capabilities, distances and access new varieties becomes difficult. For to markets as well as access to and instance, planting technology and adoption of improved technologies. distances, application regimes for Production Constraints herbicides and other weed control The major constraints identified to management practices are not adhered inhibit the production of cassava are to and this makes them unable to attain presented in Table 7. Generally, the the maximum yields. five most pressing constraints were low Constraints along the produce price, limited amount of credit Cassava Chain accessed, high cost of available labour, Reconnaissance survey in the study unavailable mechanized equipment area revealed that actors along the and limited market respectively. The cassava value chain generally face agreement among the ranking of the some constraints that impede on their constraints were significant at 1%. performance. The study investigated Since the Cassava Chain is buyer the extent to which the respondents driven, processors and distributors generally agree or disagree with these along the chain dictate the prices and constraints in the specific regions and producers are left with no option but to in the pooled sample. The regions accept the prices quoted. considered are heterogeneous in nature An Evaluation of the Cassava Value Chain in Ghana 197

Table 7: Constraints to Cassava Production

ASHANTI BRONG AHAFO NORTHERN POOLED CONSTRAINT (N=100) (N=100) (N=100) (N=300) Limited land 8.60 7.88 10.70 9.05 Limited market 6.26 5.72 8.22 6.73 Limited quality 8.39 8.88 9.75 9.02 planting materials Limited credit 5.40 5.15 5.66 5.40 Unavailable labour 8.86 9.33 8.34 8.83 High cost of available 5.94 5.40 5.43 5.59 labour

Produce perishability 7.64 8.46 7.54 7.89 Unavailable/inaccessible 6.18 5.49 6.22 5.96 mechanisation equipment Low yield 9.28 9.54 8.02 8.93 Erratic rainfall pattern 7.64 7.57 7.10 7.45 Poor/declining soil fertility 8.81 8.45 7.94 8.39 Low commodity produce 4.69 5.04 6.09 5.27 price Limited extension access 8.05 7.92 8.67 8.23 Animal grazing 9.30 10.15 5.35 8.27

Kendall’s W=0.177; Chi-square=692.051; df= 13; Sig.@ 0.000 Ranking Scale: 1=agree, 2= Don’t Know, 3= Disagree Source: Field Survey 2015 Producers in the Ashanti region for cassava in the region. The price per experience the greatest challenge of kg of cassava is GH¢0.98, GH¢0.76 low produce price as compared to those and GH¢0.29 in the Northern Region, in the Northern region. This is because Ashanti region and Brong Ahafo region cassava is not a major staple in the north respectively. However, producers in and hence, its supply is limited. This the Ashanti and Brong Ahafo regions brings about an increase in the prices experience limited market which is for the little produce available which is as a result of longer and inaccessible mainly processed into gari and cassava routes to cassava farms. The use of chips. Again, this guarantees a market mechanized equipment, even though 198 An Evaluation of the Cassava Value Chain in Ghana

generally limited, is a bit popular in and labour intensive and hence have the northern region since they operate serious challenges with health hazards on relatively larger farmlands. The associated with using traditional average land size in the Northern processing technologies as well as the region is 1.95 ha compared to 0.91ha high labour requirement. The limited and 1.42ha in the Ashanti and Northern products and promotion of cassava regions respectively. products also makes its demand limited to a section of consumers. The Processing Constraints constraints identified are presented in Most cassava processors use the Table 8. traditional methods which are obsolete Table 8: Constraints to Cassava Processing

PROCESSING ASHANTI BRONG AHAFO NORTHERN POOLED CONSTRAINTS (N=52) (N=46) (N=53) (N=151)

Health hazards 4.31 5.07 5.47 4.95

High Labour requirement 5.60 6.61 5.31 5.79

Traditional/ manual processing 4.71 5.87 5.89 5.50 Disposal of affluent from 8.67 6.53 8.18 7.84 processing Limited information on other 8.68 8.10 7.40 8.02 products Correct means of processing 7.24 7.26 7.91 7.46 products Negative perception of 8.55 8.21 8.60 8.49 cassava products Limited demand for cassava 5.97 6.62 5.92 6.14 products Limited promotion of cassava 6.90 5.84 7.68 6.83 products Expensive/cumbersome FDA 9.64 8.29 11.13 9.77 and GSA procedures Absence of quality assurance 8.17 7.50 7.25 7.67 Unreliable supply of raw 8.56 9.90 6.98 8.38 material (cassava) Water shortages 8.53 10.46 8.50 9.13

High packaging cost 9.49 8.75 8.79 9.04

Kendall’s W=0.180; Chi-square 354.073=; df= 13; Sig. @ 0.000 Ranking Scale: 1=agree, 2= Don’t Know, 3= Disagree An Evaluation of the Cassava Value Chain in Ghana 199

Majority of Processors who use the Trading Constraints improved method of ‘Good Practice’ Actors in the trading of cassava and technology are from the Northern cassava based products are usually region and they normally operate as a critically constrained with high group using shared facilities. Hence, transportation cost accompanied with they suffer less with the health hazards very poor road networks, limited access associated with traditional means of to credit and lack of storage facilities processing. The labour requirement and the bulkiness of produce making is also consequently increased in the handling costly and difficult (Table 9). Northern region since they are able to There is also a significant agreement produce larger volumes than those using among the traders in terms of their the traditional means in the Ashanti and rankings of the constraints at 1%. Northern region. Table 9: Constraints to Cassava Trading

TRADING ASHANTI BRONG AHAFO NORTHERN POOLED CONSTRAINTS (N=50) (N=50) (N=50) (N=150) High level perishability 5.37 5.50 7.50 6.13 High produce price 4.66 4.17 5.09 4.64 High transportation cost 3.88 4.28 3.71 3.92 Inconsistency in supply 5.44 5.88 5.23 5.52 Poor road network 5.00 5.56 3.97 4.84 Lack of storage facilities 4.79 4.80 3.95 4.52 Limited access credit 4.17 3.54 4.15 3.96 Bulkiness of harvested 5.94 5.75 5.48 5.73 produce Low quality produce 5.75 5.52 5.92 5.74

Kendall’s W=0.141; Chi-square 169.763=; df= 8; Sig. @ 0.000 Ranking Scale: 1=agree, 2= Don’t Know, 3= Disagree Source: Field Survey 2015 The distances from the processing therefore attract high transportation centers to markets in the Northern charges. The main roads to markets in Region are relatively longer with the Brong Ahafo and Ashanti region limited means of transportation and are however shorter and mostly tarred. 200 An Evaluation of the Cassava Value Chain in Ghana

Traders are also able to trade in large of the former largely dependent on quantities if they have the means to few dominant processors and traders. purchase more, hence limited access Producers of cassava are critically to credit is a critical concern across all constrained by the low prices of produce, regions. Nonetheless, cassava is bulky high cost of labour and limited access and highly perishable in its raw state to credit whilst processors are mostly therefore traders are unable to acquire constrained by the use of inefficient large volumes if they are not assured of traditional technologies/equipment, ready market and in the event of bad very high labour requirements and market, the lack of storage facilities in serious health hazards emanating from the major markets becomes a foremost naked fire and smoke to which they are concern across all regions. constantly exposed. Traders of cassava and cassava products are also heavily CONCLUSION constrained by high transportation The key actors in the cassava value costs, bad road networks, limited access chain are the producers of raw tubers to credit and inadequate/unavailable (cassava roots), processors of raw tubers storage facilities. Improved processing into desirable forms and the distributors equipment should be introduced in of raw tubers and value added products the cassva value chain to improve of cassava. Gari is the most popular and productivity, efficiency, product well defined processed product from quality and reduce the health harzards cassava roots in terms of processing to which propocessors are exposed. and marketing standards. It is usually Promotion of technologies that would processed either under the traditional enhance the flow of information among or improved (GPC) technology. The actors should be considered to improve type of governance exhibited along the visibility and bring about innovation and chain is buyer driven and processors are market growth along the chain. Finally, considered as the dominant actors who primary producers of cassava should exert high level of influence and control form strong associations to improve in the chain. The nature of relationship their bargaining position in the chain between producers and other actors in to ensure value chain functionality and the chain is ‘captive’ with the operations sustainability. An Evaluation of the Cassava Value Chain in Ghana 201

REFERENCES

Bair, J. (2005) ‘Global Capitalism and Commodity Chains: Looking Back, Going Forward’. Competition and Change, 9(2): 153-180 Barrientos, S., Gereffi, G. and Rossi, A. (2010) ‘Economics and Social Upgrading in Global Production Networks: Developing a Framework for Analysis’. Working Paper 2010/03. Bourgon, J. (2011) ‘The New Synthesis of Public Administration: Serving in the 21st century’. School of Policy Studies and McGill-Queen’s University Press, Pp. xv, 414. Bröring, S. (2010) ‘Developing Innovation Strategies in Times of Market Convergence’. International Journal of Technology Management, Special Issue on Technology Convergence, 49 (1): 272-294. Doner Richard F., Allen Hicken, Bryan K. Ritchie (2009) ‘Political Challenges of Innovation in the Developing World’. Review of Policy Research 26(1). Dziedzoave, N. T., Graffham, A. J., Mensah, B. A. and Gyato, M. (2002) ‘Use of Cassava Flour in Paperboard Adhesives’. In: Proceedings of the 12th Symposium of the International Society for Tropical Root Crops (ISTRC), Tsukuba, Japan : http:// www.tiu.ac.jp/~bduell/ISTRC/Symposiums/Japan.00.html Evans, P. and T. Wurster, (2000) ‘Blown to bits: How the New Economies of Information Transform Strategy’. Harvard Business School Press, Cambridge, Massachusetts, USA. FAO (Food and Agricultural Organisation) (2008). Value Chain Analysis of Cassava Subsector in Zambia. Part II: Value Chains Analysis Final Report .GTFS/ RAF/364/ITA Foreign Investment Advisory Service (FIAS) (2007): Moving Towards Competitiveness: A Value Chain Approach. Washington. The World Bank Group Gereffi, G. (1994) ‘The Organisation of Buyer Driven Global Community Chains. How US-Retailers Shape Overseas Production Networks’. In: G. Gereffi and M. Korzeneiewicz (eds), Commodity chains and Global Capitalism, USA: Greenwood Press. Gereffi G., Humphrey J, and Strurgen T (2005) ‘The Governance of Global Value Chains’. Review of International Political Economy, 12 (1):78-104 Gereffi G., Humphrey J., Kaplinsky R and Sturgeon. T. J. (2001) ‘Globalization, Value 202 An Evaluation of the Cassava Value Chain in Ghana

Chains and Development’: IDS Bulletin 32 (3): 1-8 ISSN 0265-5012 Gibbon, P. and S. Ponte, (2005) ‘Trading Down Africa Value Chains and the Global Economy’. DIIS, Copenhagen. Gibbon, P., Bair, J. and Ponte, S (2008) ‘Governing Global Value Chains: An Introduction’. Journal of Economy and Society, 37 (3):315-338 Hartwich, F., Kormawa, P., Bisallah, I. D., Odufote, B. O. and Polycarp, I. M. (2010)’ Unleashing Agricultural Development in Nigeria through Value Chain Financing’. Draft Report Hobbs, J., Cooney, A. and Fulton, M. (2000) ‘Value Market Chains in the Agri-food Sector: What are they? How do they work? Are they for me?’ Department of Agricultural Economics, University of Saskatchewan, Canada. Hopkins, T.K. and Wallerstein, I. (1994) ‘Commodity Chains’. Construct and Research: 17-20. In Gereffi, G. and Korzeniewicz, M. eds. Commodity chains and global capitalism. Westport, CT: Greenwood Press. Humphrey, J. (2003) ‘Opportunities for SMEs in Developing Countries to Upgrade in a Global Economy’. ILO SEED Working Paper No. 43, Geneva. Humphrey, J. and Schmitz, H. (2002) ‘How does Insertion in Global Value Chains Affect Upgrading in Industrial Clusters?’ Institute of Development Studies, Brighton. Regional Studies 36(9): 1017–27. Humphrey, J. and Memedovic. O. (2006) ‘Global value chains in the agri-food Sector’. UNIDO Working Paper, Brighton. IFPRI (International Food Policy Research Institute) (2008): 2007-2008 Annual Report, Washington, DC IITA (International Institute of Tropical Agriculture) (2009):The Root and Tuber System, Medium Term Plan, 2009-2011. www.iita.org ISSER (Institute of Statistical, Social and Economic Research) (2005): The state of Ghanaian Economy in 2004, University of Ghana, Legon.-Accra Ivarsson, I. and Alvstam C. G. (2005) ‘Technology Transfer from TNCs to Local Suppliers in Developing Countries: A Study of AB Volvo’s Truck and Bus Plants in Brazil, China, India, and Mexico’. World Development 33(8): 1325-1344. Jones, H. (2011) ‘Taking Responsibility for Complexity: How implementation can Achieve Results in the Face of Complex Problems’. Overseas Development Institute Research Paper 330. Jumah A., Anaglo J. and Atendem P. (2006) ‘The Demand for Cassava Food Products in Ghana’. Cassava-SME Project Report, 2006. Kaplinsky, R., Morris, M. and Readman, J. (2002) ‘The Globalization of Product Markets and Immiserizing Growth: Lessons from the South African Furniture Industry’. World Development 30(7): 1159-1177. An Evaluation of the Cassava Value Chain in Ghana 203

Kasalu-Coffin, E., Bedingar, T., Dosso, H. and Diop, E. (2005) ‘Ghana Export Marketing and Quality Awareness Project’. Appraisal Report Keare, D. H. (2001) ‘Learning to Clap: Reflections on Top-Down versus Bottom-up Development’. Human Organization Summer 2001, 60 (2). Kleih, U., Phillips, D., Wordey, M. T., Komlaga, G. (2013) ‘Cassava Market and Value Chain Analysis, Ghana Case Study’. Final Report January 2013. Kumar, S., Kant, S. (2006) ‘Organizational Resistance to Participatory Approaches in Public Agencies: An analysis of Forest Department’s Resistance to Community Based Forest Management’. International Public Management Journal 9(2). Laven, A. (2011) ‘The Ghanaian State and Inclusive Upgrading in the Global Cocoa Chain in Value chains, Social Inclusion and Economic Development: Contrasting Theories and Realities’. Edited by A.H.J. Helmsing and S. Vallema, pp 121-47. London and New York: Routledge Meridian Institute (2009) ‘Innovations for Agricultural Value Chains in Africa: Applying Science and Technology to Enhance Cassava, Dairy, and Maize Value Chains’. Cassava Value Chain Overview MSPA (Mauritius Sugar Producers’ Association), (2010) ‘Value-added Products of Sugarcane’. Retrieved from: http://www.mspa.mu/index.php?rubrique=15. Rees, D. (2012) ‘Improving the Marketing System of Yams in Ghana’. Natural Resource Institute, Greenwich University. Schmitz, H. (2004) ‘Dynamics, Innovation and Development: Local Upgrading In Global Chains’. Elsinore, Denmark. Trienekens J. H. (2011) ‘Agricultural Value Chains in Developing Countries: A Framework for Analysis. International Food and Agribusiness Management Review, (IFAMA) 14(2). UNIDO (United Nations Industrial Development Organization), (2009) ‘Agro-value Chain Analysis and Development’. A staff working paper, Vienna. Van den Berg, M., Marije, B., Ivan, C., Luigi, C., Nico, J., Paule, N., Laura, P., Tim, P., Dominic, S. and Van Wijk, S. (2008) ‘Making Value Chains Work Better for the Poor: A Toolbook for Practitioners of Value Chain Analysis, Version 3. Making Markets Work Better for the Poor (M4P). Agricultural Development International, № 38, Cambodia. World Bank (2010), World Development Report. Agriculture for Development: Washington DC. World Bank. 204

THEME II:

FOOD SCIENCE AND TECHNOLOGY RELATED ISSUES IN THE GHANAIAN ROOT AND TUBER INDUSTRY 205

Value Addition Interventions along the Root and Tuber Food Supply Chain

*ODURO Ibok, ELLIS William Otoo, BOAKYE Abena Achiaa, ARYEETEY Enoch and MANFUL Maame Ekua Department of Food Science and Technology, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana *Corresponding author: [email protected]

Introduction direction of food flow from producer to Building vibrant and sustainable Food consumer in the FSC is systematic, thus Supply Chains (FSC) is absolutely when one part of the FSC is affected, the necessary to achieve food and nutrition entire chain suffers (Vlajicet al., 2012). security. The FSC comprises a set of Lapses in the chain is often manifested interdependent actors who work together as commodity price instability, loss to manage the processes and flow of of food quality and fluctuations in the goods and services along the value- demand and supply patterns (Smith, added chains of food commodities, 2008). with the intention of meeting customer The FSC of cassava, yam, needs at the lowest possible cost cocoyam and sweetpotato, although (Folkerts and Koehorst, 1998). The similar to most food crops, is distinctive main operations within the FSC are and complex. For instance, these roots production, processing, distribution, and tubers are highly perishable and consumption and disposal (FAO, 2007). easily bruise during harvest thus the need The FSC also encompasses product for curing with subsequent processing development, marketing, finance and to minimize losses (Dapaah and Joel, customer service. Since every step of 2009; Onyenwoke and Simonyan, the FSC requires the involvement of 2014). Enhancing susceptibility to human and natural resources, it has spoilage is their relatively high moisture the potential to create jobs, provide content. Roots and tubers are also bulky income, and subsequently improve with irregular shapes and sizes posing a the livelihood of stakeholders. The challenge to their handling, processing 206 Value Addition Interventions along the Root and Tuber

and distribution (Taiwo, 2006). A point a produce with higher net worth and in case is the difficulty in design and potential to increase utilization and fabrication of machinery for their use consumption (Bradbear, 2009; Yishak, (Agbetoye et al., 2003; Sanni et al., 2014). It therefore requires integrated 2007; Kolawole et al., 2010). interventions along each unit of the Their traditional food use on FSC. This is achieved by identifying and the other hand is usually tedious, employing technologies or systems that time-consuming and inconvenient promote and enhance the market value requiring at least four unit operations; of food. Learning from the integrated washing, peeling, size reduction and value-added interventions of the Irish fermentation / boiling / roasting / potato Food Supply Chain, the end-user mashing / pounding (Onyenwoke and needs and requirements incorporated Simonyan, 2014). A review of literature right from concept generation will shows limited studies on appropriate result in market specific varieties. Such storage systems for both raw and endeavors could ultimately contribute processed fresh produce although it is to food and nutrition security in replete with studies on the packaging, Ghana; with potential for the strategy storage and shelf stability of flours, to be replicated in other West African starches and other processed products. communities. Even though some Thus, the key stages to note for an efforts are being made in this direction effective and sustainable root and tuber through research and publications, the FSC are the processing, distribution outcomes are not well coordinated and storage. and documented to guide policy and Value addition to root and tuber implementation. This chapter therefore crops is therefore essential in addressing presents past and on-going research some of the aforementioned challenges. on efforts at enhancing the utilization Any step or action in the food supply of cassava, yam, sweetpotato and chain that improves the worth of a food cocoyam; discusses appropriate produce for a “target market” is referred technologies needed at major unit(s) to as value addition (Arohit and Prateek, of the FSC for effective value addition, 2015). Efficient value addition begins and highlights existing gaps for future with the ‘end user’ in mind. The ‘end research. user’ is the ‘target market’ and this could The status of root and tuber crops be the farmer, industry or consumer. (cassava, yam, cocoyam, sweetpotato) The result of value added process is supply chain Value Addition Interventions along the Root and Tuber 207

Root and tuber crops are staple foods to be about 60% (FAO, 2011; Summers for most developing communities in and Tran, 2016). The Global agricultural the sub-tropical and tropical regions, production indices for roots and tubers feeding over a billion people and with from 1990 to 2000 have been slightly an estimated annual global per capita higher (74-94) than that of net crops consumption of 110 kg (WCRTC, 2016). (72-89). However, a reverse trend was Other non-food applications include observed for 2014 where net crops its use as animal feed or raw material recorded a production indices of 123 in the production of starch, distilled while roots and tubers 119 (FAOSTAT, spirits, and alcohol (FAO, 2003). 2015). Their importance to the economy and Exacerbating this challenge food security of developing countries are other confounding constraints can therefore not be overstated. It is to both production and utilization. noteworthy though, that the patterns These include limited postharvest of utilization vary considerably among management/technology, poor countries. collaboration among key stakeholders, With an annual global production unplanned supply chain or market of 432 million tons (MT), cassava systems for the individual commodities, is the most produced followed by limited value addition interventions as sweetpotato, yam, and cocoyam, well as lack of policies and or their having 237 MT, 130 MT, 53 MT, and 12 implementation (Oduro, 2016a). In MT production capacities, respectively. Ghana, recent interventions on the China and Nigeria are the leading promotion and growth of the roots and world producers and Ghana is ranked tubers have mainly been addressed seventh (FAOSTAT, 2013). There has by the West African Agricultural been a general increase in production Productivity Programme (WAAPP) levels in Africa from 2010 as a result and Root and Tuber Improvement of increased research interventions and Marketing Programme (RTIMP). (FAOSTAT, 2014). Production The RTIMP sought to develop a however, is mostly by small-holder competitive, market-based and an all- farmers in rural communities and the inclusive root and tuber commodity harvests, characterized by substantial chains by providing relevant, effective postharvest losses. Although there is and sustainable services that is limited reliable data for predicting especially accessible by the rural poor these losses some authorities estimate it whereas the WAAPP project which is 208 Value Addition Interventions along the Root and Tuber

currently ongoing seeks to generate and also seem not to be a ready market disseminate improved technologies in for this product. Both projects have top priority areas with respect to the somewhat yam and cassava value chains. neglected the sweetpotato and The RTIMP project introduced cocoyam commodity chains. Table high quality cassava flour production 1 shows the SWOT (Strengths, in Ghana. However, this technology Weaknesses, Opportunities and has not been successfully accepted and Threats) analysis of the existing root adopted by the local processors. There and tuber FSC. Value Addition Interventions along the Root and Tuber 209 /availability all /availability climate for for climate measure for for measure for measure Opportunities Production round year of utilization Industrial tuber and root Favourable production Stopgap famine Large scale production Stopgap famine Large scale production varieties not wholly wholly varieties not of produce during off off during produce of Threats genetically against Prejudices modifiedfood Improved producers to accessible for lands farm Unavailable production change Climate Declining soil fertility services extension Insufficient workingInaccessible capital Scarcity seasons – / characteristics Undesired in as acrid factors such effects taro services extension Insufficient workingInaccessible capital confined to confined more on farmers’ farmers’ on more intensive , internal colour and and colour , internal cost of labour; of Labour cost Weaknesses Focused preference High intensive Cultivation (smallholder) subsistence cultivation uneven farming; - Lesser produc and yields area to compared tivity cultivation under technology/ Inadequate technical transfer Limited improved to access materials planting and consuming Time dishes of recipes tedious Lack mechanization of Shape in colour changes technology/ Inadequate technical transfer Labour to different climatic climatic different to to cultivate under under cultivate to planting materials planting local recipes produce crop , high-yielding, disease of farmer varieties farmer of Strengths Adaptable conditions development and Research varietal im - around centered provement New varieties resistant Flexibility - inter-crop mono-cropping, farming mixed and ping the affecting without systems productivity climatic adverse to Adaptable conditions Available Use development and Research downstream around centered processing Available Available Breeding Production Processing Stages along the along Stages R&T FSC Table 1. Summary of strengths, weaknesses, opportunities and threats along the root and uber food supply chain along the root weaknesses, opportunities and threats 1. Summary of strengths, Table 210 Value Addition Interventions along the Root and Tuber measure for for measure Large scale production Large scale production /expanding Increasing local international and market Stopgap famine of produce produce of of produce during off off during produce of Scarcity extension services extension Insufficient - technologi of Lack adoption of cal intervention of price market Unstable produce – seasons off during Scarcity seasons – of price market Unstable produce services extension Insufficient - improved stor intensive perception about about perception perishability uptake of value added value of uptake age techniques/ facilities techniques/ age Wrong R&T products - pro Limited commercial facilities cessing Poor entrepreneurs by products start-ups and workingInaccessible capital Inadequate technology/ Inadequate technical transfer workingInaccessible capital Low market to degree organization , unorganized Disjointed - the develop to approach the trade of ment Weak systems transport with areas linking farming markets in high Bulkiness resulting transportation of cost Labour toInability appropriately of price market determine produce High Inadequate - added prod value /ready market /ready dissemination dissemination Information - tech processing improved of niques Adequate ucts Available - /commu household Improved systems nity-based storage Commercialization Product Development Distribution and Marketing Storage Value Addition Interventions along the Root and Tuber 211 Large scale production demand consumer High in population Increase Potential in substituting animal for grain imported feed post-harvest losses productivity, limited value value limited productivity, and irregular shapes shapes Bulkiness, irregular and sizes and High Low poor to access and addition markets moisture content moisture - techno of Lack adoption of logical intervention workingInaccessible capital High Highly perishable Bulkiness shapes , irregular sizes and - Minisett planter Minisett peeler Yam slicer/dicer Yam Dryer Yam blancher/ Yam Steamer/Parboiler machine Roasting machine Pounding mash Sweetpotato er - tech processing technologies: measure for famine for measure • • • • • • • • Improved niques Available uptake Leading Industrial to resilient Considered climate crops Stopgap other to Cheaper compared food crops Source: (Acheampong and Osei-adu, 2015; Dapaah and Joel, 2009; Wera, et al., 2016) (Acheampong and Osei-adu, 2015; Dapaah Joel, 2009; Wera, Source: Mechanization entire the Across FSC 212 Value Addition Interventions along the Root and Tuber

It should be noted that, since each tailored for specific food and feed use root and tuber crop has its peculiar has been addressed (Goddard et al., challenges, there is the need for specific 2015). Notable studies include the interventions along the food supply release of yellow cassava and sweet chain for each crop. cassava by IITA for the gari and ethanol industries, respectively. The yellow Strengths and opportunities cassava variety with relatively high along the root and tuber beta-carotene content is a target crop food supply chain with health benefits. The sweet cassava Root and tuber crops have been varieties contain between 17.47- earmarked as major crops towards 39.62% starch (Richardson, 2013; achieving sustainable food and Ezeigbo et al., 2015) and up to 17% nutrition security by 2050 (Ref). sucrose with traces of dextrose and This is with regard to their ability to fructose (Charles et al., 2005). Thus, withstand adverse climatic conditions ethanol production from its juice will especially, cassava and cocoyam. Some require comparatively little hydrolysis. underutilized species of yam, Dioscorea Also, the release of orange-fleshed and bulbifera, Solenostemon. rotundifolius purple-fleshed sweetpotato varieties by and Dioscorea dumetorum, are used as the International Potato Centre (CIP) is stop gap measure for famine in some step in line as a dietary intervention for communities. The potential for many the prevention of vitamin A deficiency more to be used for sustainable food and among rural African communities. feed has been investigated (Uchendu, With a rapidly increasing global 1969; Zannou, 2006). population and more mouths to feed, root Efforts have been made in the and tuber crops can possibly compete development of improved root and with the importation of cereal grains for tuber varieties that are early maturing both human and animal feed in tropical (Mackenzie, 1997), high yielding and sub-tropical areas. To this effect, and have dry matter content (Baafi there has been accelerated research and et al., 2015, 2016) as well as those development efforts on tropical root and that are pest and disease tolerant, and tuber crops to maximize their potential can withstand the impacts of climate benefit to the human race based on their change. These traits chiefly represent competitive advantage as compared to the farmer preferences. The potential other crops. Cassava and yam research for development of new varieties has been in the forefront followed Value Addition Interventions along the Root and Tuber 213 by sweetpotato and then cocoyam. Agricultural Tropical (CIAT), Food and These research contributions are being Agriculture Organization (FAO) as well supported by local research institutions as higher institutions of learning such as such as the Councils for Scientific Universities and technical/ vocational and Industrial Research (CSIR) and colleges. Table 2 shows a list of some Governmental Agencies such as the projects carried out on root and tubers Ministries of Food and Agriculture in West Africa over the past 20 years. (MoFA) and Environment and The eventual goal for these research and international research institutions such development endeavours is to ensure a as International Institute for Tropical market stable and all year round supply Agriculture (IITA), International or availability of raw root and tuber Potato Centre (CIP), National Research crops and their processed produce. Institute (NRI), Centro International de 214 Value Addition Interventions along the Root and Tuber Research Objective(s) Research - reduc at aimed is project proposed The income postharvesting losses, increasing the actors key food securityand among improved through chain value thein yam systems storage yam and nutritional the quality, optimize To promote cassava, of health implications poverty part as of incomes household employment and initiatives reduction and rural communities targeting creation youth To contribute to the national research research the national to contribute To scientific providing by capacity and solid baseline data, knowledge, performance monitor methodologies to yam, (cassava, tuber and root of chains value potato) sweet and cocoyam, in Ghana market-based a competitive build To Chain Commodity Tuber Root and KNUST University Aalborg College of University Nordjylland DTU - KNUST CSIR-CRI McGill IITA KNUST Agric. of University Makurdi Agric. of Univ. Federal Abeokuta NRCRI FIIRO Implementing institution(s) Funding Agencies Funding Agency Australian International for Development IFAD DANIDA Centre Fellowship and GoG IFAD 2013-2017 2007-2014 2005-2013 Duration 2013-2015 2014-2016 - Root and Tuber Root and Tuber Improvement and marketing (RTIMP) Project Project Title Project Root Strengthening Value Tuber and Chains in Ghana Improved Yam Stor Improved Yam Security Food for age (IYSFSI) Income and Quality, Improving Health: and Nutrition Inclusion of Impacts in Flours Cassava of Formulations Bread Africa in West 4 Source 3 1 2 Table 2. Names of some root and tubers research projects in West Africa (1996-2016) and their research objective(s) Africa (1996-2016) and their research in West projects and tubers research 2. Names of some root Table Value Addition Interventions along the Root and Tuber 215 Developing value chains for HQCF for chains value Developing - Nige Uganda, Tanzania, in Ghana, Malawi. ria and - technol and knowledge provide To of the development allow ogies to linking small-holder chains value for markets growth to farmers climate of HQCF in the context & variability. change - multi for system a sustainable Develop improved of distribution and plication tubers. and roots for materials planting pest management integrated an Develop to control, biological including system, disease pests of and the incidence reduce research adaptive on-farm Strengthen - new crop of the availability increase and techniques. processing and storage ping, partic - farmers, resource-poor Empower they have that ensure to women, ularly - technol improved to access unimpeded ogies. MoFA KNUST CSIR-CRI CSIR-FRI University of Greenwich University of Agric. Abeokuta CSIR-FRI Food and Tanzania Nutrition Africa Innovations Institute Chancellor College – of Malawi Univ. IITA CSIR-FRI IFAD Bill and Melinda Gates Foundation European Commission - 1997-2003 2010-2017 Root and Tuber Root and Tuber Improvement (RTIP) Project Adding Cassava: (C:A - Africa for Value II VA) - Liveli Improving hood Small Holder of Farmers Cassava Better Access through Markets Growth to Gmarkets) (Cassava 5 6 7 216 Value Addition Interventions along the Root and Tuber - - - the postharvest manage improve To leading yams and cassava of ment losses, reduced physical reduced to - value-add losses through economic of valorization and ed processing products. waste - CIP IITA KNUST - CIP European Union European - IFAD Asian Development Development Asian Bank, Austrian Ministry Finance, of Melinda Bill and Gates Foundation International The Fertilizer Group Life International Sciences Royal Institute Danish Ministry Foreign of Affairs 2006-2008 2012-2014 2010-2014 2004-2007 . Sweetpotato breeding breeding Sweetpotato West for program Africa Diverse and New Devel - Products Food D.oped from alata Gains from Losses of Losses of from Gains Crops Tuber Root and (Grattitude) Sweetpotato Harvest Harvest Sweetpotato Project Plus - - - 8 Value Addition Interventions along the Root and Tuber 217 ------Guinness/CSIR-CRI/Depart KNUST Biochemistry, of ment KNUST KNUST - - IFAD/WECARD/ IITA Ghana Guinness Limited CASHPRO Agricultur National Projects al Research Roots and (NARP) Programme Tubers USAID/CORAF (WE CARD) Project SONGHAI 2002-2006 1999 to 2001 1998 to 1999 1997 to 1999 - - Screening and and Screening cassava selection of materials varieties as use Brewing as for Adjunct - Sweet of Prospects varieties for potato - pro starch industrial animal and duction feeds in Ghana of Characterization different from Starch - Sweetpo of cultivars tatoes Post-Har Improving Quality and vest Rice, of Packaging Millet and Sorghum, Products Cassava - Market Enhance to ability Africa in West Poverty Alleviation Alleviation Poverty Food Enhanced and in West Availability - Africa Im through - technol Yam proved ogies - - - - - 218 Value Addition Interventions along the Root and Tuber - improve genetic of the rate increase To bet- develop to breeding in cassava ment Selection. Genomic varieties through ter To develop improved varieties, improved develop To pests control technologies, production crops tuber and diseases root and of increased a sustainable ensure to production. - - Beijing Genomics Beijing Genomics Institute CIAT Cornell University · · · - NRCRI University State Ebonyi CSIR-CRI CSIR-SARI CNRA of Faculty d’Ivoire, Côte of Technology Science and - Biotech of Dassa (Laboratory and resources genetic nology, breeding animal and plant -BIORAVE). - Bill and Melinda Melinda Bill and Foundation Gates - Bill and Melinda Melinda Bill and Foundation Gates - - - - Controlling diseases Controlling and potato in sweet Sudan enset in South Ethiopia and Generation Next Breeding Cassava Cassava) (NEXTGEN National Root and Root and National - Im Crops Tuber Project provement (NRTCIP) AfricaYam – AfricaYam yam Enhancing increased for breeding productivity and in quality improved Africa West Transformation Yam System - - 9 - Value Addition Interventions along the Root and Tuber 219

http://www.iita.org/web/yiifswa/home, Assessed 15th January, 2016 10:06pm- http://iitanews.blogspot.com/2010_02_01_archive.html, Assessed on 15th Janu- ary, 2017; 6:14pm European Union’s African, Caribbean Research Institute (CRI); Council and Pacific Science and Technology for Scientific and Industrial Research Programme (EU-ACP); Centro (CSIR) - Food Research Institute International de Agricultural Tropical (FRI); Council for Scientific and (CIAT); Beijing Genomics Institute Industrial Research (CSIR) - Savanna (BGI); Kwame Nkrumah University Agricultural Research Institute (SARI); of Science and Technology (KNUST); National Root Crops Research Institute Council for Scientific and Industrial (NRCRI); Centre National de Recherche Research (CSIR) – Crops Research Agronomique (CNRA), Federal Institute (CRI); Council for Scientific Institute of Industrial Research and Industrial Research (CSIR) – Food Oshodi (FIIRO); Technical University Research Institute (FRI); Council for of Denmark (DTU); International Scientific and Industrial Research Institute for Tropical (CSIR) – Savanna Agricultural Research Agriculture (IITA), International Institute (SARI); National Root Crops Potato Centre (CIP); International Fund Research Institute (NRCRI); Centre for Agricultural Development (IFAD); National de Recherche Agronomique Government of Ghana (GoG); (CNRA), Federal Institute of Industrial Aside the easy adaptability of Research Oshodi (FIIRO); Technical roots and tubers to adverse climatic University of Denmark (DTU); conditions, they require flexible International Institute for Tropical farming practices and can thrive under Agriculture (IITA), International mono-cropping, inter-cropping and Potato Centre (CIP); European Union’s mixed farming systems with little African, Caribbean and Pacific Science adverse effect on productivity (Preston, and Technology Programme (EU-ACP); 2001). Also, the planting materials for Centro International de Agricultural the cultivation of these crops are readily Tropical (CIAT); Beijing Genomics available especially, that of cassava and Institute (BGI); Kwame Nkrumah yam (Ceballos et al., 2004; Tetteh and University of Science and Technology Saakwa, 1994). (KNUST); Council for Scientific and Industrial Research (CSIR) - Crops 220 Value Addition Interventions along the Root and Tuber

Value addition through processing is scaling up of either conventional and a crucial step to promoting root and non-conventional processing or both. It tuber crops as it allows the production is usually marked by larger production of shelf-stable products with increased capacities and the use of sophisticated consumer appeal as well as longer equipment. Because of the complexities storability and convenience for year- of the process, the process flows and round supply. Generally, the processing plant layout may slightly differ from that of root and tuber crops, can be classified of conventional or non-conventional into four domains, namely, traditional/ processing. conventional processing, non- The increasing consumer demand conventional processing, value-added for convenience in food preparation processing and industrial processing. and use as well as diversity and all year The traditional processing of root and availability (Ali and Kapoor, 2010) tubers include those techniques for coupled with the fact that existing producing traditional dishes and some root and tuber based dishes generally other secondary products. Examples have difficult-to-follow and time- include the production of gari, kokonte, consuming recipes, makes product agbelima, abacha, agblikaklo, ampesi, development crucial in seeking to meet fufu, tapioca, Ԑtͻ (eto) and wasawasa. consumer needs. Product development Oduro, (2016b) outlined the recipes is a strong transforming tool for even of existing cassava-based traditional the underutilized roots and tubers with dishes to serve as in-roads for further the right attention and appropriate research on innovative recipes. technologies. Also, peculiar intrinsic The non-conventional processing characteristics of roots and tubers techniques result in the production of such as taste and colour are exploited non-traditional root and tuber products. through product development for Some examples of non-conventional diversification. processing include the production of For instance, the sweet taste of High Quality Cassava flour (HQCF), sweetpotatoes has been explored yam flour, sweetpotato flour and by food scientists and technologists to puree, alcohol, high fructose syrup, optimize their utilization in products glucose, dextrin, native and modified such as instant doughnut mixes, instant or pre-gelatinized starches. Industrial pancake mixes, sweetpotato-based processing sometimes referred to as complementary foods, juices and ‘large-scale processing’ involves the yogurt as well as in pastry products Value Addition Interventions along the Root and Tuber 221 from either the sweetpotato flour or millet blend, yam-tamarind blend puree. Another venture for product and sweetpotato-cowpea-millet blend development is the combination of root processed either as breakfast meals, and tuber crops with other food crops snacks or complementary foods. Table to complement their nutrient strength. 3 shows selected product development Some of such products include, cassava- endeavours from the various root and soybean blend, cocoyam-cowpea- tuber crops. 222 Value Addition Interventions along the Root and Tuber References (Falade and Akingbala, 2008) and (Falade 2014) et al., (Salvador, Akingbala, 2010) and (Falade (Baah, 2009) 2016) (Nyarko, (Salma and Zaidah,(Salma and 2006) 2013; et al., (Amagloh Zaidah,Salma and 2006; 1998; Padmaja, Hagenimana, Owori and 2012) et al., Developed product Tapioca, Cassava Chips and pellets, unfermented cassava starch and and starch cassava pellets, unfermented and Chips Cassava Tapioca, reep, cassava dumby, manicure ampesi, fufu, bread, cassava flour, fried chips, cassava pappad, wafer, puddings, cassava macaroni, Oyek, Chick-wangue, Kasili, Farima, Banu/Uala, beiju, beer, cassava Agbelima, Gari Akyeke/Attieké, Lafun, Gatot, tape, flour Peujeum, roots), - beverag cassava Rale (roasted flour, Cassava Cooked cassava, Mahewu) and Impala es (Oteka, Beer Drink Farinha, (Chicha), (Manicuera) Bread, Flour, Gari, - Amala, Ikokore/ik Boiled yam, Roasted yam, Fufu, yam, Pounded Fried yam flour, yam Poundo Dried chips/pellets, yam pankwukwo, chips slices yam frozen Ready-to-prepare Crisps, Chips, Crackers, Caker, Ayam, Cakes, Mashed potatoes Cakes, Mashed Ayam, Caker, Crackers, Chips, Crisps, (Porridge) Atapa Dried cubes, Dry used fruit, Baked in making Pectin sweetpotato, Fry, French Flour, Sweetpotato Pickles, Sweetpotato Jellies, and Jams - Sweetpota Restructured flour, based complementary Sweetpotato Frozen Canned Sweetpotato, candies, Hard (RSS), Curd, Sticks to Noodles,Sugar flakes, Sweetpotato puree, Sweetpotato Sweetpotato, sauce beverages, Non-alcoholic and (Shochu) Alcoholic Syrups, Root and Tuber Root and Cassava Yam Sweetpotato Table 3. Selected product development cases from cassava, yam, sweetpotato and cocoyam development cases from 3. Selected product Table Value Addition Interventions along the Root and Tuber 223 (Ojinnaka et al., 2009; Sanful & Darko, (Ojinnaka 2009; Sanful et al., & Darko, 2014) et al., 2010; Owusu-Darko, (Ojinnaka 2013) et al., 1996) Eneh, and Onwuka Beer Fufu Flour, chips, Flour for pastries for Flour chips, Flour, Fufu food in complementary Starch Modified Cocoyam 224 Value Addition Interventions along the Root and Tuber

The leaves and petioles of cassava, of studies have confirmed the positive cocoyam and sweetpotato remain useful effect of traditional processing methods for various food, feed and medicinal in reducing the cyanogenic potential of applications. For example, cocoyam the leaves (AttahDaniel et al., 2013; leaves also known as kontomire in Ghana Hidayat, et al., 2002). It has also been is popular in diets of convalescents and established to have equal taste, flavour pregnant women to combat anemia. It and overall acceptability, as that of is known to have appreciable levels Amaranthus, a popular leafy vegetable, of iron, phosphorous, calcium and when used in soups (Awoyinka et al., vitamins A and C (Opara, 2003). The 1995). Sweetpotato leaves on the major drawback to its utilization other hand, are primarily used as vines however is its acridity (reduced to safe for planting but can also be used as levels by traditional cooking processes) vegetables in soups, stews and salads. and high perishability after harvest They have been successfully used in (3-5 days maximum) necessitating the the production of green tea of high need for shelf-stable processed forms. nutritional and commercial value There are ongoing studies to develop (Koomson, 2005) further situating shelf stable purees for stews, soups and its potential industrial exploitation in sauces, as well as, minimally processed diverse food applications. leaves with vacuum packaging. There In order to match the consumption may be opportunities for its flour as demand of the rapidly growing well and farmers could be encouraged populace with supply, there must be to cultivate cocoyam for its leaves a paradigm shift from traditional should the appropriate markets be farming practices of intensive manual developed. They are currently harvested labour to mechanized farming. as secondary products from farms for Significant advancement has been cormel/ root production (Acheampong made over the years in the development et al., 2015). Cassava leaves are also of mechanized technology for the popular vegetables for sauces and cultivation, harvesting, processing soups in Nigeria, Sierra Leone, Liberia and storage of root and tuber crops and Ghana. (Kolawole and Agbetoye, 2007). The leaves consist of about 29.3– Amponsah et al. (2014) reported 32.4% protein (Awoyinka, et al., 1995), the development of a mechanical with some varieties having significantly cassava harvester, Itodo and Daudu high cyanogenic potential. A number (2013) evaluated the performance of Value Addition Interventions along the Root and Tuber 225

a tractor mounted yam harvester fitted evaluated the performance of a cassava with a collection unit and Bosrotsi, chipping machine. In spite of these et al. (2017a, 2017b) developed a advances in root and tuber processing mechanical yam harvester. In another technologies, gaps still remain for study, Akinbamowo et al. (2011) construction of mechanized cassava, developed a mechanical harvestor for peeling machine and cocoyam peeling cocoyam. In Rwanda, the plough-ox and slicing machine. There is also the has been adopted for the harvesting need for concerted efforts to promote of sweetpotato roots. These harvesters and commercialize the available provide a more efficient and cost technologies. effective root recovery system and Among the root and tuber crops, they are ideal for use by large scale fresh cassava is the least shelf- stable root and tuber producers. Not many with deterioration commencing right investigations have been reported after harvest. It can last 3-5 days on mechanized planting systems employing traditional storage methods. for tropical roots and tubers and the Cassava roots can be waxed to extend process still relies heavily on manual its shelf-life for the fresh produce labour. Obigboh and Akubuo (1991) market. Cocoyam (Xanthosoma reported the development of a two-row sagittifolium) cormels are the most automated minisett yam planter while shelf-stable, reported to last up to Odigboh, (1978) and Hariharan, et al. six months with traditional storage (2015) reported design and fabrication methods (Personal communication, of cassava planters. There are a number Farmer interviews in 2014). Yams also of mechanized technologies employed have relatively high shelflife with some in the processing of root and tuber species particularly, D. alata storing crops for both domestic and industrial for months with traditional storage applications. methods (Baah 2009). Sweetpotatoes Ayodeji, et al. (2014) reported the have fairly short shelflife with roots development of an industrial peeling shrinking (a consumer quality defect) and slicing machine for yam. Other after few weeks of storage. commonly known technologies include The triple-S and sand-box storage the mechanical graters, hydraulic and have been developed as improved screw presses, solar dryers, millers, household storage systems for fufu pounding machine and sweetpotato extended shelflife (Namanda, 2012). puree machine. Bolaji, et al., (2008) Emerging technologies that may be 226 Value Addition Interventions along the Root and Tuber

employed are evaporative cooling research findings as reports to funding systems, cold-storage chain systems agencies, peer refereed articles and and irradiation technologies. However, conference/seminar presentations for these techniques are expensive and the scientific community. may not be cost-effective alternatives A number of training programmes for small-holder farmers. Development for beneficiaries and stakeholders were of appropriate low-cost packaging and carried out in the past but they lacked preservation technologies could further follow up interventions and post- extend the shelf-life of these crops and training assessments. The International especially, the processed products. At Potato Centre (CIP) has taken the lead present, vacuum packaging presents a in addressing these lapses especially for more affordable alternative for small sweetpotato value chains in Africa under and medium scale processors along the Sweetpotato Action for Security the root and tuber value chains. The and Health in Africa (SASHA) and technique has been used for a number Sweetpotato for Health Initiative (SPHI) of locally manufactured non-root/tuber umbrellas. Also, a training module products on the market to enrich the knowledge of trainers The demand of root and tuber for about the utilization and processing of both domestic and industrial usage is orange-fleshed sweetpotato has been fairly stable and fast-expanding. There developed by CIP-Ghana (Abidin et is both the drive demand, which is the al., 2015). Similar interventions could desire to transform the fresh root and be exploited for cassava, cocoyam tuber into secondary products of higher and yam for enhanced utilization and value, and composite drive, which is sustainability of value chains. There the desire of having several uses for a is opportunity to incorporate plant and particular raw material (Nweke, 2004). process designs as well as hygienic There is also an expanding international and food safety procedures such as market for both fresh root and tuber Hazard Analysis Critical Control produce and processed products. To Point (HACCP) and Standard Sanitary foster commercialization and build Operating Procedures (SSOP) into stronger market systems, concerted these training modules for efficiency efforts to develop and implement in production and sustainability of new information dissemination programmes business ventures from novel or value and training modules is essential. The added products from the crops. commonest means is the publication of Value Addition Interventions along the Root and Tuber 227

2.2 Weaknesses and threats urbanization and industrial expansion along the root and tuber (Sanni et al., 2009). Although knowledge food supply chain on best agronomic practices for the root Although the past few decades and tuber crops exist, constraints such focused on breeding root and tuber as low soil fertility, inaccessibility to varieties that meet the quality improved varieties, disease and pest preference of the farmer, to wit, high attacks and inadequate funding to carry yields and big-sized roots/ tubers. out necessary farming activities (such Recent dietary changes and consumer as purchase of inorganic fertilizers preferences require a paradigm shift to and the use of irrigation system) are breeding varieties with tailored end- still prevalent hindering production. uses. For example, the breeding and Others include lack of efficient post- selection of varieties that are consistent harvest storage methods, lack of in shape, size and weight as large- staking materials in yam production sized root and tuber crops is a limiting and insufficient extension services factor for packaging and transportation. (Okigbo, 2005; Tetteh and Saakwa, Traders for the export market may 1994). Exacerbating the constraints require smaller-sized produce. Another is the strong competition with cereals drawback is the inadequate germplasm on the basis of nutrition, diversified preservation for some varieties/ species products and all year availability. due to over-reliance/ preference for The aim of storage is to ensure some cultivars such as D. rotundata Poir all year supply by managing glut for yams. Other technical challenges and avoiding scarcity. This ensures a to breeding and selection of suitable balance in demand and supply all year varieties include long breeding cycles thereby preventing price fluctuation. such as that for cocoyam (Personal Many farmers do not have effective communication, 2014), and very low storage systems on site to regulate the multiplication ratio of propagules as supply of root and tuber crops during compared to other crops. the bumper season. Small-holder farmers constitute Also, the unavailability of the largest percentage of root and appropriate storage facilities at tuber crop producers. A major threat households, commercial markets encountered by these small-holder (wholesale and retail points) and farmers is the inaccessibility to farm processing facilities increases the land due to land ligation problems, postharvest losses along the FSC. 228 Value Addition Interventions along the Root and Tuber

Currently, it is difficult to estimate is the unwholesome kokonte (food the quantitative and qualitative losses from fermented cassava flour) saga that occur from harvesting, handling, in Ghana which was heightened after transportation and storage for each a news bulletin by a local newspaper commodity due to absence of formal/ (Ghanaian Chronicle, October 19, regulated supply channels from all 1999). The general inconvenience in major production areas. Available preparation of root and tuber dishes also data are mainly estimates (FAO, 2011; limits their utilization especially among Okigbo, 2005). Contributing factors to urban dwellers. Thus, consumption and high losses at storage include improper patronage of most traditional dishes handling practices, lack of improved from root and tuber crops is on the packaging and storage materials/ decline. Associated myths and stigma to techniques, field pest infestation and the consumption of root and tuber crops difficulty in control of toxicity as well also hinder consumer acceptance of as microbial spoilage. Others include products. Examples include, flatulence the imbalance between market demand associated with sweetpotato, cyanide and cultivation/ harvesting of produce. toxicity with cassava and piles with A delimiting factor to industrial/ cocoyam. Also, there is poor uptake of large-scale processing of root and tuber value added products by entrepreneurs crops lies in the fact that they remain and start-ups (Kayode et al., 2017) seasonal crops with yam having one- hence the need for profitability and time harvest in a yea. This seasonality economic feasibility assessment of root brings about a huge constraint in and tuber processed foods to encourage making returns in industrial processing commercialisation. since start-up capital and cost of Existing methods of transportation equipment and installation needed (and transport systems), packaging, and for processing are quite expensive. general handling of roots and tubers are Thus, processing of root and tuber ineffective resulting in huge postharvest crops is confined to cottage industries losses of produce (FAO, 2011; Okigbo, where maintaining consistent product 2005). quality and performance continue There is also difficulty in to be a challenge. As expected, assembling reliable market data. This incidences of product adulteration arises from the fact that trade and and fraud, are rampant. Examples of or markets are usually informal and such reports (and sometimes hearsays) disjointed making it difficult to establish Value Addition Interventions along the Root and Tuber 229

produce demand by the different market by the actors’ preference with little segments. Another common challenge consideration for the target market. encountered during the marketing and Though some products from this sales of root and tuber is the inability system may be good, many end up not of producers to determine the market meeting the needs and requirements of price for their produce. They are the other actors along the supply chain usually exploited by the middle men especially the consumer. Thus, the and “market queens” who ultimately potential recurrence of food waste and put price tags on farmers produce. food loss. Learning from interventions These notwithstanding, it is along the supply chain of the Irish noteworthy that the overall prevailing potato, Solanum tuberosum, it is critical weakness of root and tuber value chains to incorporate end-users and major is the high annual postharvest losses stakeholders’ needs, requirements and (Aidoo, 1993; FAO, 2011; Kayode et preferences right from the start of the al., 2017). Thus, the need for mitigating concept generation for new varieties to efforts to curb it at each unit of the value promote utilization and thus, optimal chains. production levels of the crops. This involves capturing the views of both Way forward: Future industry and final consumers, and prospects synthesizing their feedback into on- The potential avenues for improving going breeding programs for subsequent the root and tuber Food Supply value addition ventures. A case in point Chains are enormous. Having a is how the phenotypic characteristics thorough understanding of the of potato have been exploited to physiology, biochemical and molecular meet target market needs: Three such characteristics, as well as the nutritional varieties are highlighted. First, thin- benefits of a particular root and tuber crop skinned, small (round/ovoid-shaped) allows for more efficient exploitation roots for the salad market. during breeding, agronomy, storage, These require only washing processing, product development and and cooking (boiling or steaming) commercialization. operations removing the need to peel Presently, most value addition and reduce size before preparation activities carried out by the different and or consumption. The second is actors along the root and tuber Food large, thick-skinned varieties that are Supply Chain are influenced largely usually irregular shaped. These are 230 Value Addition Interventions along the Root and Tuber

produced mainly for domestic use tuber varieties were bred mainly on providing consumers with more food farmer preferences; on-going breeding at a lower cost. The third variety is programs should be geared towards the large, thin-shinned regular shaped producing new varieties/accessions multipurpose roots usually used in that satisfy the preferences of both the industrial production of chips. Here, target market and the farmer. Superior equipment fabrication for processing and desired crop traits can be achieved is easier as roots are uniformly shaped. through the use of modern selective This diversity, greatly promotes the breeding techniques like genome and utilization of the crop and drives gene mapping and cell/tissue culturing. production. Solanum tuberosum has Releasing varieties with uniform production levels of 333MT/year morphology such as regular and (WCRTC, 2016); being approximately consistent shapes, consistent variation half of current total world root and in weight, and desired textural properties tuber crop production. A new era of will ease the design and fabrication of an integrated value-addition process machinery for use by both cottage and along each unit of the root and tuber large-scale industries. Other potential FSC has dawned and all actors along areas of focus for roots and tubers the FSC must have the right mindset, varietal improvement programs include by putting on “the value addition lens” germplasm that are early maturing and for each unit along the chain. This in capable of performing better with low addition to the desire of meeting the inputs and can survive biotic and abiotic end-users’ preferences will help curtail stress conditions. New varieties could postharvest losses along the value be bred with the aim of supplementing chain. foods with essential micronutrients for The principle of garbage- public health interventions. in, garbage-out is hundred per cent On-going breeding programmes applicable to all processes along the such as beta-carotene rich cassava entire root and tuber Food Supply by IITA Nigeria and CSIR-Ghana Chain. When a poor-quality root or (WCRTC, 2016) and beta-carotene rich tuber variety, which does not meet a plus high dry matter for sweetpotatoes by target market specification, is selected CIP-Ghana (Personal communication, for cultivation, the end result is a wasted, CIP-Ghana) are good examples to stunted or deficient supply chain. Since emulate for other health interventions. most currently cultivated root and These studies, are multidisciplinary, Value Addition Interventions along the Root and Tuber 231

integrating the needs of primary for both fresh produce and processed stakeholders along the supply chain products will enhance their shelf especially that of the final consumer stability and minimize losses. One for enhanced success. However, it is such adoptable technology is the important that, the DNA markers of triple-S system developed for storing varieties with resilient climate change fresh sweetpotatoes by CIP – Ghana traits are explored with each proposed (Abidin et al., 2016). The technology breeding intervention. is cheap, easy-to-practice and adaptable It is reported that irrespective of to diverse environments and could be the mode of cultivation (subsistence, explored for other root crops that are small-scale or large scale) for roots also used as seed systems such as and tubers, the annual production cocoyam. yields per hectare of land is generally Processing of fresh produce into below the expected in developing shelf stable products could also enhance countries (FAO, 2003). A plausible their storability and ensure year-round means for mitigating this constraint is availability. Generally, root and tuber to provide concerted interventions that crops are processed into flours or starches capture good agronomic practices and for other end-uses. This could be done enhanced accessibility to credit and in composite with other ingredients extension services. Key components to complement their nutrient strength of such interventions should include: and also provide diversity. Extrusion the development, evaluation and cooking and drum-drying originally implementation of training modules employed for diversifying the food use on basic financial management and of cereals, could be explored. good-record keeping to boost farmers’ Adams (2016) investigated the use access to credit and capacity building of extrusion cooking in the development of leaders from various farmer groups of a snack from yam-tamarind blend to function as extension support staff. and Laryea (2016) employed drum- In order to extend the shelf-life of drying in the development of an root and tuber crops, storage practices orange-fleshed sweetpotato based after harvesting and curing, and at each complementary food. Both experiments unit along the entire root and tuber were successful resulting in consumer- FSC, is key. Thus, the development acceptable and market-viable products. of appropriate cost-effective storage Another avenue for exploitation is technologies (systems and facilities) purees from the root and tuber crops. 232 Value Addition Interventions along the Root and Tuber

The process is a cheap technique which uptake of developed products. In this retains nutritional value of crops and regard, there is also need for studies the purees, can be used in diverse food aimed at improving traditional/ applications as well as stored for later indigenous dishes for convenience in use. Orange-fleshed sweetpotatoes preparation and use to meet growing have especially been explored in this market demand for convenient foods. wise. The puree has been used in This may be accomplished through yogurt production (Manful et al, 2016), conventional processing, non- development of complementary foods conventional processing or minimal (Twumasi, 2017), baked products and processing techniques. Okyere (2017) for enriching a traditional cookie from investigated the processing parameters cassava (Grant et al, 2017). In essence, and shelf-stability of ready-to-prepare food scientists recommend the use of yam slices for a popular Ghanaian purees over flours in development of dish, ‘ampesi’ and Boakye et al. (2016) new products from the orange-fleshed and Kwarkye et al. (2017) developed varieties as the technique retains a ready-to-prepare forms of ‘eto’ and greater portion of the beta-carotene ‘mpotompoto’, traditional delicacies, (Andualem et al., 2016; Muzhingi from processed cocoyam, respectively. et al., 2016). There is also need for More of such studies, could help in studies into appropriate packages for the long term, to reignite consumption root and tuber value added products. of root and tuber dishes in urban and In an era where developing countries peri-urban areas as well as create new are suffering from environmental market niches in international trade pollution resulting from use of for the crops towards their enhanced polyethylene packages, investigations utilization and demand. on the manufacture of appropriate It is worth mentioning that biodegradable and reusable packages the role of entrepreneurs is crucial for both fresh produce and processed in the success of such efforts. An products will be advantageous. entrepreneurial drive is essential for Other urgent areas that need to be the sustainability of all value addition addressed for sustainable food supply interventions along the Food Supply chains of the root and tuber crops include Chain. Without entrepreneurs in the standardization and optimization of the food supply chain, all proposed existing recipes to ensure consistent interventions to strengthening the product quality for efficient industrial FSC cannot be supported. There is the Value Addition Interventions along the Root and Tuber 233

need to map out appropriate markets (or non-governmental) partnerships. segments and potential investors to Fora for regional markets for the translate research findings to ensure its marketing and distribution of roots relevance to society. and tubers must be encouraged and A good index for industrializing existing informal ones, strengthened. and commercializing the production Accurate and reliable data base for as well as the utilization of roots and production, processing, trade and tubers lies in the ability to employ consumption is also needed to foster mechanized technologies along the trade relations. It is also important to entire supply chain. There have been evaluate and improve existing systems adequate advances in technologies for for information/ technology transfer for planting, harvesting and to an extent, rural and peri-urban stakeholders and processing of the various root and tuber producers in particular. To fully exploit crops. However, machinery for peeling, the potential food applications of roots washing and slicing are still lacking and tubers especially the underutilized and these operations remain labour varieties, research interventions should intensive and costly. There is the need characterize their molecular processing for such studies to develop appropriate behavior for in-depth understanding and cost effective equipment for use by and exploitation of their processability. both cottage and large-scale industries. Techniques such as Nuclear Also, since environmental protection is Magnetic Resonance (NMR), of great concern and directly influences Differential scanning calorimetry climate change, the establishment (DSC), Hyperspectral Imaging of good manufacturing practices for and Fourier Transform Infrared reducing levels of industrial waste and Spectroscopy (FTIR) could be employed pollution should be proposed. There is for such investigations (Dissing et al., also the need to develop operational 2013; Frosch et al., 2011; Mortensen et protocols for industries on best practices al., 2005; Tananuwong & Reid, 2004; to remove undesirable properties such Chatakanonda et al. , 2003). as acridity and antinutitrive factors In light of the above discourse, from the crops. Pilot plants with sole effective collaboration/network among aim of ensuring a smooth scale-up of the civil society, science and technology, processed products from roots and business and the government agencies, tubers is also essential. This requires cannot be overemphasised. The multi- both public (governmental) and private stakeholder and interdisciplinary 234 Value Addition Interventions along the Root and Tuber

approach is essential to improving varieties should be geared towards the utilization of root and tuber crops meeting the needs, requirements along the FSC. Also, adopting the and preferences of a specific target participatory approach of research will market along the root and tuber FSC. enhance the uptake of technologies Having a thorough understanding by stake-holders. This can be done by of the physiology, biochemical and engaging all relevant stakeholders along molecular characteristics, as well as the Food Supply Chain in the planning, the nutritional benefits of a particular execution and implementation for root and tuber crop allows for more future projects. Capacity of researchers efficient exploitation during breeding, and key stakeholders along the value agronomy, storage, processing, product chain should be built to harness their development and commercialization. creative and innovative ideas for Such interventions require a multi- enhanced productivity of the root and stakeholder and interdisciplinary tuber crops. collaboration alongside the participatory The paradigm shift for addressing research approach for effective uptake the postharvest challenges of root of technologies and new knowledge and tuber crops is integrated value towards a more productive and addition interventions along each unit sustainable root and tuber food supply of the Food Supply Chain having the chains in Ghana, with potential for end-user and major stakeholder needs strategy replication in other West and requirements at the heart of each African communities. projection and or research. Thus, the breeding of new root and tuber Value Addition Interventions along the Root and Tuber 235

REFERENCES

Abidin, P. E., Dery, E., Amagloh, F. K., Asare, K, Amoaful, E.F. and Carey, E. E. (2015). Training of trainers’ module for orange-fleshed sweetpotato (OFSP). Utilization and processing. International Potato Center (CIP); Nutrition Department of the , Tamale (Ghana). 32pp. Acheampong, P., Osei-adu, J., Amengo, E., & Sagoe, R. (2015a). Cocoyam Value Chain and Benchmark study in Cocoyam Value Chain and Benchmark study in Ghana Report to the West Africa Agricultural Productivity Programme Patricia Pinamang Acheampong, (April). https://doi.org/10.13140/RG.2.1.4295.6326 Acheampong, P., Osei-adu, J., Amengo, E., & Sagoe, R. (2015b). Cocoyam Value Chain and Benchmark study in Ghana. https://doi.org/10.13140/RG.2.1.4295.6326 Adams, Z. S. (2016). Improved Yam-Baobab-Tamarind Flour Blends and Its Potential Use in Extrusion Cooking. Kwame Nkrumah University of Science and Technology. Agbetoye, L. A. S., Ademosun, O. C., Ogunlowo, A. S., Olukunle, O. J., Fapetu, O. P., & Adesina, A. (2003). Engineering challenges in developing indigenous machinery for cassava production and processing. Proc. Ann. Conf.of the Nigerian Soc. Eng. (Lagelu 2003), 80–86. Aidoo, K. E. (1993). Post-harvest storage and preservation of tropical crops. International Biodeterioration and Biodegradation, 32(1–3), 161–173. https://doi. org/10.1016/0964-8305(93)90048-7 Akinbamowo, R. O., Ogunlowo, A. S., & Agbetoye, L. A. S. (2011). Development of a Tractor-mounted Cocoyam (’Xanthosoma spp.’) Harvester. Australian Journal of Agricultural Engineering, 2(3), 82. Amagloh, F. K., Mutukumira, A. N., Brough, L., Weber, J. L., Hardacre, A., & Coad, J. (2013). Carbohdrate composition, viscosity, solubility and sensory acceptance of seetpotato – and maize based complementary foods. Food and Nutrition Research, 57, 1–9. https://doi.org/10.3402/fnr.v57i0.18717 Amponsah, S. K., Bobobee, E. Y. H., Agyare, W. A., Okyere, J. B., Aveyire, J., King, S. R., & Sarkodie-Addo, J. (2014). Mechanical cassava harvesting as influenced by seedbed preparation and cassava variety. Applied Engineering in Agriculture, 30(3), 391–403. https://doi.org/10.13031/aea.30.10495 Andualem, A., Kebede, A., & Abadi, G. M. (2016). Development of pro-vitamin A and 236 Value Addition Interventions along the Root and Tuber

energy rich biscuits: Blending of orange-fleshed sweet potato (Ipomea batatas L.) with wheat (Triticum vulgare) flour and altering baking temperature and time. African Journal of Food Science, 10(6), 79–86. https://doi.org/10.5897/ AJFS2015.1403 Arohit, G., & Prateek. (2015). Value Addition in Packaging : Delight to the Industry. International Journal of Engineering Research, 4(4), 184–187. AttahDaniel, B. E., Ebisike, K., Adeeyinwo, C. E., Ojumu, T. V, Olusunle, S. O. O., & Adewoye, O. O. (2013). Towards Arresting the Harmful Effect of Cyanogenic Potential of Cassava to Man in the Environment. The International Journal of Engineering and Science (IJES), 2(9), 100–104. Awoyinka, A. F., Abegunde, V. O., & Adewusi, S. R. (1995). Nutrient content of young cassava leaves and assessment of their acceptance as a green vegetable in Nigeria. Plant Foods for Human Nutrition, 47(1), 21–28. Retrieved from http:// www.ncbi.nlm.nih.gov/pubmed/7784394 Ayodeji, S. P., Akinnuli, B. O., & Olabanji, O. M. (2014). Development of Yam Peeling and Slicing Machine for a Yam Processing Plant. Journal of Machinery Manufacturing and Automation, 3(4), 74–83. Baafi, E., Blay, E. T., Ofori, K., Gracen, V. E., Manu-Aduening, J., & Carey, E. E. (2016). Breeding Superior Orange-Fleshed Sweetpotato Cultivars for West Africa. Journal of Crop Improvement, 30(3), 293–310. https://doi.org/10.1080/15427528. 2016.1154492 Baafi, E., Manu-Aduening, J., Carey, E. E., Ofori, K., Blay, E. T., & Gracen, V. E. (2015). Constraints and Breeding Priorities for Increased Sweetpotato Utilization in Ghana. Sustainable Agriculture Research, 4(4), 1. https://doi.org/10.5539/sar. v4n4p1 Baah, F. D. (2009). Characterization of water yam (Dioscorea Alata) for existing and potential food products. Kwame Nkrumah University of Science and Technology. Retrieved from http://ir.knust.edu.gh:8080/handle/123456789/616 Boakye, A. A., Kissi, A. K., Wireko-Manu, F. D., Chronakis, I., Guðjónsdóttir, M., & Oduro, I. (2016). Enhancing the food utilization of cocoyam: Development of Ԑtɔ- mix. In First Congress on Root and Tuber Crops. Nanning Guangxi, China. Bolaji, B. O., Adejuyigbe, S. B., & Ayodeji, S. P. (2008). PERFORMANCE EVALUATION OF A LOCALLY DEVELOPED CASSAVA CHIPPING MACHINE. South African Journal of Industrial Engineering, 19(1), 169–178. Bosrotsi, C. K., Addo, A., Dzisi, K. A., & Agodzo, S. K. (2017a). Development of a Yam Harvester using Finite Element Method. International Journal of Modern Studies in Mechanical Engineering, 3(1), 35–44. Bosrotsi, C. K., Addo, A., Dzisi, K. A., & Agodzo, S. K. (2017b). Technical Performance Value Addition Interventions along the Root and Tuber 237

and Economic Feasibility Assessment of A Mechanical Yam Harvester. International Journal of Research Studies in Agricultural Sciences, 3(3), 1–10. Bradbear, N. (2009). Value-Added Products In: Bees and their role in forest livelihoods. (N. Bradbear, Ed.). Rome: FAO. Ceballos, H., Iglesias, C. A., Pérez, J. C., & Dixon, A. G. O. (2004). Cassava breeding: opportunities and challenges. Plant Molecular Biology, 56(4), 503–516. https:// doi.org/10.1007/s11103-004-5010-5 Charles, A. L., Sriroth, K., & Huang, T. (2005). Proximate composition, mineral contents, hydrogen cyanide and phytic acid of 5 cassava genotypes. Food Chemistry, 92(4), 615–620. https://doi.org/10.1016/j.foodchem.2004.08.024 Chatakanonda, P., Chinachoti, P., Sriroth, K., Piyachomkwan, K., Chotineeranat, S., Tang, H. R., & Hills, B. (2003). The influence of time and conditions of harvest on the functional behaviour of cassava starch – A proton NMR relaxation study. Carbohydrate Polymers, 53(3), 233–240. https://doi.org/10.1016/S0144- 8617(03)00047-X Dapaah, H., & Joel, S. (2009). West African Productivity Programme ( W A A P P ) , Ghana. Baseline Survey Report. Dissing, B. S., Papadopoulou, O. S., Tassou, C., Ersbøll, B. K., Carstensen, J. M., Panagou, E. Z., & Nychas, G.-J. (2013). Using Multispectral Imaging for Spoilage Detection of Pork Meat. Food and Bioprocess Technology, 6(9), 2268– 2279. https://doi.org/10.1007/s11947-012-0886-6 Ezeigbo, O. R., Ukpabi, C. F., & Ekaiko, M. U. (2015). Determination of Starch and Cyanide Contents of Different Species of Fresh Cassava Tuber in Abia State , Nigeria. British Biotechnology Journal, 6(1), 10–15. https://doi.org/10.9734/ BBJ/2015/15297 Falade, K. O., & Akingbala, J. O. (2008). Improved Nutrition and National Development Through the Utilization of Cassava in Baked Foods. In G. L. Robertson & J. R. Lupien (Eds.), Using Food Science and Technology to Improve Nutrition and Promote National Development (pp. 1–12). International Union of Food Science & Technology. Falade, K. O., & Akingbala, J. O. (2010). Utilization of Cassava for Food. Food Reviews International, 27(1), 51–83. https://doi.org/10.1080/87559129.2010.518 296 FAO. (2003). Proceedings of the Expert Consultation on Root Crop Statistics – Volume I. Rome. Retrieved from http://www.fao.org/docrep/005/y9421e/y9421e00.htm FAO. (2007). Agro-industrial supply chain management: concepts and applications. Rome (Vol. 17). Retrieved from http://aglinks.net/sites/default/files/agro- industrial_supply.pdf 238 Value Addition Interventions along the Root and Tuber

FAO. (2011). Global food losses and food waste – Extent, causes and prevention (Gustavsson). Rome: FAO. FAOSTAT. (2013). FAO Statistical Yearbook. Food and Agriculture Organization of the United Nations. Rome: FAO. https://doi.org/10.1017/CBO9781107415324.004 FAOSTAT. (2014). FAO Statistical Yearbook 2014 – Near East and North Africa Food and Agriculture. FAO. FAOSTAT. (2015). FAO Statistical Pocketbook 2015. Food and Agriculture Organization of the United Nations. Rome: FAO. https://doi.org/978-92-5-108802-9 Folkerts, H., & Koehorst, H. (1998). Challenges in international food supply chains: vertical co-ordination in the European agribusiness. British Food Journal, 100(8), 385–388. Frosch, S., Dissing, B. S., Adler-Nissen, J., & Nielsen, M. E. (2011). Spectral imaging as a tool in food research and quality monitoring of food production. In I. Akyar (Ed.), Wide Spectra of Quality Contro (p. 532). InTech. Retrieved from http://www. intechopen.com/books/wide-spectra-of-quality-control/spectral-imaging-as-a- tool-in-food-researchand-%0Aquality-monitoring-of-food-production Goddard, J., Harris, K. P., Kelly, A., Cullen, A., Reynolds, T., Anderson, L., … Investigator, P. (2015). Root, Tuber, and Banana Textural Traits: A Review of the Available Food Science and Consumer Preferences Literature. Evans School Policy Analysis and Research (EPAR), (295), 1–52. Grant, F. W., Oduro, I., Wireko-manu, F. D., & Zaukuu, J. Z. (2017). A Traditional Biscuit Fortified with Orange-Fleshed Sweet Potato Puree and Cowpea Flour. Food Science and Nutrition Technology, 2(2), 1–1. Hariharan, K. V., Pradeep Kumar, S. P., Prasanth, M., & Senthil Kumar, R. (2015). Design and Fabrication of Tapioca Planter. International Journal of Innovative Research in Science, Engineering and Technology, 4(6), 565–570. Hidayat, A., Zuraida, N., & Hanarida, I. (2002). The Cyanogenic Potential of Roots and Leaves of Ninety Nine Cassava Cultivars. Indonesian Journal of Agricultural Sciences, 3(1), 25–32. Itodo, I. N., & Daudu, J. O. (2013). Performance Evaluation of a Tractor Mounted Yam [Dioscorea spp.] Harvester fitted with a Collection Unit. In 2013 Kansas City, Missouri, July 21 – July 24, 2013 (p. 1). St. Joseph, MI: American Society of Agricultural and Biological Engineers. https://doi.org/10.13031/ aim.20131592710 Kayode, R. M. O., Buhari, O. J., Otutu, L. O., Ajibola, T. B., & Oyeyinka, S. A. (2017). Physicochemical Properties of Processed Aerial Yam ( Dioscorea bulbifera ) and Sensory Properties of Paste ( Amala ) Prepared with Cassava Flour. The Journal of Agricultural Sciences, 12(2), 84–94. Value Addition Interventions along the Root and Tuber 239

Kolawole, O. P., & Agbetoye, L. A. S. (2007). Engineering Research to Improve Cassava Processing Technology. International Journal of Food Engineering, 3(6), 1–13. https://doi.org/10.2202/1556-3758.1311 Kolawole, P. O., Agbetoye, L., & Ogunlowo, S. A. (2010). Sustaining world food security with improved cassava processing technology: The Nigeria experience. Sustainability, 2(12), 3681–3694. https://doi.org/10.3390/su2123681 Koomson, G. M. (2005, November 3). Preparation of green tea from sweetpotato leaves. KNUST. Retrieved from http://ir.knust.edu.gh/handle/123456789/1580 Kwarkye, A. O., Wireko-Manu F. and Boakye A. A. (2017). Development of convenient mpotompoto. 6th One-Day Ghana Science Association (GSA) Research Seminar and Poster Presentations, Fumesua, Kumasi, Ghana. Laryea, D. (2016). Value addition of Sweetpotato: Production of a Complementary Food from a Blend of Sweetpotato, Millet and Soyabean. Thesis submitted to Kwame Nkrumah University of Science and Technology, in partial fulfillment of requirements for Master of Philosophy degree in Food Science and Technology. Mackenzie, D. (1997). Report on the Inter-Centre Review of Root and Tuber Crops Research in the CGIAR. Rome. Manful, M.E., Owusu-Mensah, E., Boakye, A.A. and Oduro, I. (2016). Recipe Standardization for production of sweetpotato yoghurt. Proceedings of the fifth One-Day Research Seminar and Poster Presentations, Ghana Science Association, Kumasi. April 13. Mortensen, M., Thybo, A. K., Bertram, H. C., Andersen, H. J., & Engelsen, S. B. (2005). Cooking Effects on Water Distribution in Potatoes Using Nuclear Magnetic Resonance Relaxation. Journal of Agricultural and Food Chemistry, 53(15), 5976–5981. https://doi.org/10.1021/jf0479214 Muzhingi, T., Mbogo, D., Low, J., Magnaghi, A., Heck, S., & Gule, S. (2016). Effect of Baking on the β-carotene Content of Orange Flesh Sweetpotato (Ipomoea batatas) Puree Bread and OFSP Flour Bread. The FASEB Journal, 30(1), lb635-lb635. Retrieved from http://www.fasebj.org/content/30/1_Supplement/lb433.short Namanda, S. (2012). Current and potential systems for maintaining sweetpotato planting material in areas with prolonged dry seasons : a biological , social and economic framework By Sam Namanda A thesis submitted in partial fulfilment of the requirement for the Degree of Doc. UNIVERSITY OF GREENWICH. Nweke, F. (2004). NEW CHALLENGES IN THE CASSAVA TRANSFORMATION IN NIGERIA AND GHANA Environment and Production Technology Division International Food Policy Research Institute. International Food Policy Research Institute. Obigboh, E. U., & Akubuo, C. O. (1991). A two-row automatic minisett yam planter 240 Value Addition Interventions along the Root and Tuber

prototype. Journal of Agricultural Engineering Research, 50, 189–196. Odigboh, E. U. (1978). A two-row automatic cassava cuttings planter: Development, design and prototype construction. Journal of Agricultural Engineering Research, 23(2), 109–116. https://doi.org/10.1016/0021-8634(78)90042-2 Oduro, I. (2016). WAAPP-Ghana National Centre of Specialisation on Root and Tuber Crops. In Research in Root and Tuber Crops Value Chain Development: The Hope for Food Security in The ECOWAS Sub-region. (p. 22). Fumesua-Kumasi: CSIR- CRI. Retrieved from http://www.waapp.org.gh/waappmedia/reports/47-waapp- ncos-conference-book-of-abstracts/file Oduro, I. N. (2016). Other Cassava-based Products. In Tropical Roots and Tubers (pp. 451–477). Chichester, UK: John Wiley & Sons, Ltd. https://doi. org/10.1002/9781118992739.ch10b Okigbo, R. N. (2005). Biological control of postharvest fungal rot of yam (Dioscorea spp.) withBacillus subtilis. Mycopathologia, 159(2), 307–314. https://doi. org/10.1007/s11046-004-2454-8 Okyere, F. (2017). Effects of Minimal Processing and Freezing on Sensory Quality of Boiled and Fried Yam. Kwame Nkrumah University of Science and Technology in partial fulfillment of requirements for the Master of Science degree in Food Science and Technology. Onwuka, N. D., & Eneh, C. O. (1996). The cocoyam, Xanthosoma sagittifollium, as a potential raw material source for beer brewing. Plant Foods for Human Nutrition, 49(4), 283–93. Retrieved from http://www.ncbi.nlm.nih.gov/pubmed/8983054 Onyenwoke, C. A., & Simonyan, K. J. (2014). Cassava post-harvest processing and storage in Nigeria : A review. African Journal of Agricultural Research, 9(53), 3853–3863. https://doi.org/10.5897/AJAR2013.8261 Owori, C., & Hagenimana, V. (1998). Development of sweet potato snack products in rural areas: Case study of Lira District, Uganda. Paper presented at the 7th Triennial Symposium of the International Society for Tropical Root Crops-Africa Branch (ISTRC-AB), Cotonou, Benin. 11-17 October 199. Retrieved from http:// agris.fao.org/agris-search/search.do?recordID=GB2012102280 Owusu-Darko, P. G., Paterson, A., & Omenyo, E. L. (2014). Cocoyam (corms and cormels)—An underexploited food and feed resource. Journal of Agricultural Chemistry and Environment, 3(1), 22–29. https://doi.org/10.4236/ jacen.2014.31004 Padmaja, G., Jaffer, S. T., & Moothandassery, S. S. (2012). Food Uses and Nutritional Benefits of Sweet Potato. Fruit, Vegetables and Cereal Science and Biotechnology, 6(1), 115–123. Retrieved from http://www.globalsciencebooks.info/Online/ GSBOnline/images/2012/FVCSB_6(SI1)/FVCSB_6(SI1)115-123o.pdf Value Addition Interventions along the Root and Tuber 241

Preston, T. R. (2001). Potential of cassava in integrated farming systems. https://doi. org/10.1007/s10706-017-0176-1 Richardson, K. V. (2013). QUALITY CHARACTERISTICS, ROOT YIELD AND NUTRIENT COMPOSITION OF SIX CASSAVA (Manihot esculenta Crantz) VARIETIES. Nassau, Bahamas. Salma, O., & Zaidah, I. (2006). SWEETPOTATO FOR THE PRODUCTION OF NUTRITIOUS FOOD PRODUCTS. Acta Horticulturae, (703), 117–124. https:// doi.org/10.17660/ActaHortic.2006.703.12 Salvador, E. M., Steenkamp, V., & Mccrindle, C. M. E. (2014). Production , consumption and nutritional value of cassava ( Manihot esculenta , Crantz ) in Mozambique : An overview. Journal of Agricultural Biotechnology and Sustainable Development, 6(3), 29–38. https://doi.org/10.5897/JABSD2014.0224 Sanni, L., Alenkhe, B., Edosio, R., Patino, M., & Dixon, A. (2007). Technology transfer in developing countries: Capitalizing on equipment development. Journal of Food, Agriculture and Environment, 5(2), 88–91. Sanni, L. O., Onadipe, O. O., Ilona, P., Mussagy, M. D., & Abass, A. (2009). Successes and challenges of cassava enterprises in West Africa : a case study of Nigeria , Bénin , and Sierra Leone. International Institute of Tropical Agriculture and Common Fund for Commodities. https://doi.org/10.1017/CBO9781107415324.004 Smith, B. G. (2008). Developing sustainable food supply chains. Philos Trans R Soc Lond B Biol Sci, 363(1492), 849–861. https://doi.org/10.1098/rstb.2007.2187 Summers, G., & Tran, B. (2016). From harvest to market, NRI targets postharvest losses with next-generation information system. Retrieved January 25, 2017, from http:// www.nri.org/news/2016/from-harvest-to-market-nri-targets-postharvest-losses- with-next-generation-information-system Taiwo, K. A. (2006). Utilization Potentials of Cassava in Nigeria: The Domestic and Industrial Products. Food Reviews International, 22(1), 29–42. https://doi. org/10.1080/87559120500379787 Tananuwong, K., & Reid, D. S. (2004). DSC and NMR relaxation studies of starch-water interactions during gelatinization. Carbohydrate Polymers, 58(3), 345–358. https://doi.org/10.1016/j.carbpol.2004.08.003 Tetteh, J. P., & Saakwa, C. (1994). PROSPECTS AND CONSTRAINTS TO YAM PRODUCTION IN GHANA. Acta Horticulturae, (380), 355–359. https://doi. org/10.17660/ActaHortic.1994.380.55 Twumasi, G. A. (2017). The use of OFSP puree in complementary foods. Kwame Nkrumah University of Science and Technology. Uchendu, V. (1969). Yams. An Account of the Nature, Origins, Cultivation and Utilisation of the Useful Members of the Dioscoreaceae. D. G. Coursey. 242 Value Addition Interventions along the Root and Tuber

Humanities Press, New York, 1968. xiv + 230 pp., illus. $9.50. Tropical Agriculture Series. Science, 163(3872), 1188–1188. https://doi.org/10.1126/ science.163.3872.1188 Vlajic, J. V., Van Der Vorst, J. G. A. J., & Haijema, R. (2012). A framework for designing robust food supply chains. International Journal of Production Economics, 137(1), 176–189. https://doi.org/10.1016/j.ijpe.2011.11.026 Wera, B., Pawilnga, R. P., Ramakrishna, A., Kawale, G., & Deros, M. (2016). Assessing Performance Of Improved Cassava Genotypes For Fresh And Dry Root Yield In The Highlands Of Papua New Guinea. In Third International Conference of the Global Cassava Partnership for the 21st Century – GCP21-III 17th International Symposium of the International Society for Tropical Root Crops Assessing. WCRTC. Yishak, Y. (2014). Byproducts Utilization from Wheat Milling Industries for Development of Value Added Products. Zannou, A. (2006). Socio-economic, agronomic and molecular analysis of yam and cowpea diversity in the Guinea-Sudan transition zone of Benin. Retrieved from http://library.wur.nl/WebQuery/wda/lang/1818292 243

Enhancing the food applications of cocoyam (Xanthosoma sagittifolium): Deductions from a three- year study

Abena Achiaa Boakye*a,c, Faustina Dufie Wireko-Manua, María Gudjónsdóttirb, Ioannis Chronakisc, Akosua Korang Kissia, Frances Magnus-Georgea, Ana Carina Mendesc, William Otoo Ellisa and Ibok Oduroa a Kwame Nkrumah University of Science and Technology, Department of Food Science and Technology, UPO, PMB, Kumasi, Ghana. b University of Iceland, Faculty of Food Science and Nutrition, Vínlandsleið 14, 113 Reykjavík, Iceland. c Technical University of Denmark, DTU-Food, Nano-Bio Science Research Group, Søltofts plads, Building 227, Kongens Lyngby, Denmark *Corresponding author’s email:[email protected]

Abstract prospective contributions of cocoyam Xanthosoma sagittifolium (Cocoyam), to the local food industry, the factual is food for over 400 million people and perceived challenges to cocoyam worldwide and is the aroid of most food use and proposes plausible economic value in WestAfrica. However, avenues to increase cocoyam food it is marginalized in both national use. Requisite information on the and regional research interventions prospects of cocoyam to the local and resulting in paucity of information on regional food industry is presented its processing characteristics, limited providing the first steps to promoting existing food application, and a lack the food application of Xanthosoma of updated dishes to meet changing spp on the global front. consumer needs. This chapter draws on Introduction a three-year research work ococoyam Globalisation and associated in Ghana, to discuss the prospects urbanization has led to distinct changes and new perspectives for increased in dietary patterns and food cultures of use towards sustainable food and most developing countries (Vasantha nutrition security. It highlights the et al., 2015). Consumers increasingly 244 Enhancing the food applications of cocoyam

demand diversity, as well as easy-to- Nigeria, where the starchy cormels and use, and ready-to-eat food products that leaves additionally provide an alternate require less time in preparation and use source of income for many small holder (Ali and Kapoor, 2010; Thompson and subsistence farmers (Onyeka, 2014). Amoroso, 2014). The use of indigenous However, cocoyam has been largely crops and in particular, most tropical root marginalised in both national and and tuber staples (cassava, cocoyam, regional research interventions on staple sweetpotatoes, yam), are typically root and tuber crops (Acheampong non-existent in these westernised et al., 2015; Ramanatha et al., 2010). food cultures. To wit, consumption of Thus, its optimal food use has not many traditional delicacies from staple been fully realised, and it remains root and tuber crops in the developing an underexploited food resource. countries, has declined in urban and Cocoyam food use is relegated to time- peri-urban settlements with a number consuming, difficult-to-prepare home- of delicacies almost becoming extinct made recipes, which have made most of in urban diets. its existing dishes unattractive to urban Considering the non-sustainable dwellers. This reduced food use of prospects of continued importation cocoyam, presents a potential loss of not of westernised convenient foods in only indigenous cocoyam delicacies in a developing economy, there have local diets, but also the loss of a viable been proposals to exploit indigenous crop for sustainable regional food and staples in diverse food applications nutrition security (Acheampong et al., for sustainable food and nutrition 2015; Ramanatha et al., 2010). security (Lebot, 2009; Onyeka, 2014; This chapter draws from a three- Ramanatha et al., 2010). One such year research that investigated the root crop of interest is Xanthosoma processing characteristics of cocoyam sagittifolium, commonly referred to (Xanthosoma sagittifolium) and its as cocoyam, together with Colocossia exploitation in novel food product esculenta and other edible aroids. development, as well as tested the Xanthosoma sagittifolium (cocoyam) feasibility of improving indigenous provides essential nutrition for millions cocoyam dishes for convenience in of people in tropical regions (Ramanatha preparation and use. Deductions from et al., 2010). It is integral to the livelihood the study are used as basis to discuss the of many communities and households prospects of enhanced cocoyam use to in West Africa, particularly Ghana and sustainable food and nutrition security. Sagitate leaves of X. sagittifolium Petioles of X. sagittifolium

Enhancing the food applications of cocoyam 245

Prospective contributions The crop has high production levels of cocoyam to the with up to 19 tons/hectare and 35 tons/ local food security hectare reported in China and Egypt, Xanthosoma sagittifolium (Plate 1), respectively (Onyeka, 2014). It is provides sustenance and livelihood commonly referred to as a volunteer crop due to the prolific regeneration of setts for millions, spanning Oceania, the when fields are cleared, even after years Pacific Islands, and Africa (CABI, of dormancy (Doku, 1966; Quaye et al., 2014). 2010). The cormels also have relatively good storability, and can maintain its quality over four months after harvest in traditional storage. It can also be left underground until needed, making it available all year round (Onyeka, 2014). These properties make cocoyam a valuable resource, and thus used as a stop-gap measure against famine in farming communities (Acheampong et al., 2015), and is a good resource for poverty alleviation (Onyeka, 2014). Unfortunately, indiscriminate use Plate 1a: Typical Xanthosoma sagittifolium L. Schott plant of multipurpose weedicides in most farming communities of West Africa has with time substantially limited the prolific regeneration characteristic of cocoyam, forcing farmers to lose their setts, and by default the planting material. Thus, producers have to regularly seek for new planting material, especially in mixed cropping systems [Personal communication, (Stakeholder Plate 1b: Typical starchy cormels of surveys in cocoyam-growing areas in Xanthosoma sagittifolium found in Ghana) 2013]. Considering the afore- Ghana mentioned importance of cocoyam to the livelihoods of rural farmers, it is 246 Enhancing the food applications of cocoyam

expedient that agricultural policies are they could have substantial amounts of enacted to support the production and phytochemicals as well, inferring from utilisation of the crop. their pigmentation, which ranges from Every portion of the cocoyam plant, pale green to purple. The inferences e.g. the corm and cormels, petioles and are purely speculative, and an leaves, is edible (Bermejo and León, investigation into the exact nutritional 1994), providing an overall larger and phytochemical composition of the proportion of available food per plant. petioles would create avenues for further The crop is also estimated to have food and nutraceutical applications. higher nutritional value than many Additionally, development of novel other tropical root and tuber staples food products and convenient ready- (Ekwe, 2009). The leaves are rich in to-use forms of the leaves and petioles micronutrients, and are a good source could attract their consumption in non- of vitamin A (Opara, 2003). Traditional cocoyam producing areas, providing customs in cocoyam growing areas in new markets for increased utilisation Ghana encourage frequent consumption (Boakye et al., 2018). The cormels on of dishes from the leaves by pregnant the other hand, are energy-dense, with women and lactating mothers for some varieties containing over 85% good health (Personal communication, carbohydrates (by direct measure), consumer survey in cocoyam and starch content up to 59%. Thus producing areas), and it is a common there is the potential contribution practice for medical practitioners to of the roots to meeting the energy recommend its frequent consumption requirements of consumers when used for convalescence, among other things. in food applications. Moreover, the However, consumption of cocoyam is cormels have long been assumed to limited in some major producing areas, have relatively good digestibility over such as Nigeria (Chukwu et al., 2008; many other tropical root and tuber Onyeka, 2014), and its consumption crops (Ekwe, 2009), based on their could be encouraged through starch microstructure from microscopic development of culturally-acceptable studies (Sefa-Dedeh and Agyir-Sackey, dishes and novel food products. The 2002; Falade and Okafor, 2013). A petioles (shoots) are known to have high study on the in vitro starch hydrolysis amounts of vitamin C (Opara, 2003), of two commercial varieties, confirm and contain high amounts of dietary this assertion. The method as described fibre (CABI, 2014). It is postulated that by Englyst et al. (1992) was followed Enhancing the food applications of cocoyam 247

and the initial findings is presented in Figure 1.0.

Figure 1.0: Percent hydrolysed starch of the fresh, and cooked cormels of cocoyam as a function of time of modelled digestion.

The white-fleshed variety showed incubation (Englyst et al., 1996). High higher (p < 0.05) levels of hydrolysed SDS, and to an extent, RS fractions, are starch after 120 min of digestion, while preferred in foods for the management the red-fleshed variety had relatively of many chronic diseases (Asp, 1994; higher amounts of hydrolysed starch at Champ et al., 2003). The findings the initial stages of digestion (0 – 30 further supports the crucial importance min). Starch granules differ in their of cocoyam, in particular the white- rates of digestion and absorption, and fleshed variety, to national and regional are grouped into three main nutritional food and nutrition security. categories based on their digestibility, Earlier studies support the i.e. rapidly digestible starch (RDS) potentials of both native and modified – hydrolysed within the first 20 min cocoyam starch in diverse industrial of enzyme activity, slowly digestible food applications (Sefa-Dedeh and starch (SDS) – hydrolysed within Agyir-Sackey, 2002; Lawal 2004; 20 – 120 min of enzyme activity, and 2005; Lawal et al., 2007). Ojinnaka et resistant starch (RS) – which refers to al. (2009) explored the use of the starch unhydrolysed starch after 120 min of in a baked product, and subsequently, in 248 Enhancing the food applications of cocoyam

a complementary gruel (Ojinnaka et al., due to the relatively lower starch yield 2013), while Sanful and Darko (2010) from cocoyam compared to cassava, used the flour in combination with another staple root crop in sub-Saharan wheat in the development of rock cake. Africa, the food use of cocoyam starch The functional and pasting properties could be explored primarily as a by- of flours of some varieties have also product of a primary industrial process. been investigated (Falade and Okafor, The crop has significant food 2014), supporting the prospective use use as part of local diets in the areas of the flours in baking, and as food of domestication. Prominent among thickeners. Sefa-Dedeh and Agyir- these are the Pacific Islands, and West Sackey (2004) also studied the chemical and Central Africa, where they are composition of two commercial major staple crops (Acheampong et al., cocoyam varieties, and the influence of 2015; Ramanatha et al., 2010; Onyeka, processing protocols on their oxalate 2014). It is the third most important composition. Both flours had an root and tuber staple in Ghana, and has appreciable composition of minerals, been proven to be a significant crop for especially in the apical portions of the sustaining livelihoods in rural farming cormels, and the oxalate content was households in the West and Central significantly reduced by drum-drying, African regions. On the whole, Nigeria, indicating safe food consumption. The Ghana, and Cameroon account for more prospects for expanding the food use than 60% of the total world production, of the cormels in novel ready-to-eat and most of the produce are locally products such as fries and chips is also consumed as food (Onyeka, 2014). It high. also has substantial use as food and feed Further molecular studies by in Asia. In spite of these current uses, the Gudjonsdottir et al. (2016) on the use of cocoyam in novel food products, characteristics of the water-starch as well as improvement of indigenous interactions of cocoyam flour and dishes to modern preparation and use, starch suspensions during heating and has not been widely explored for wider cooling, also showed their prospective markets. Lessons could be drawn from use as commercial gels, thickeners, the strategies employed in the successful and binders, and demonstrated their promotion and utilisation of Colocasia potential for use in baked products, as spp in Japan towards establishing it as well as the suitability of the flours for a household crop in both urban and use in complementary gruels. However, rural communities, and subsequently Enhancing the food applications of cocoyam 249

providing a niche for its products on the pigmentation of commercial varieties global market (Ramanatha et al., 2010). requires interventions for cultivars with enhanced colour uniformity to further Challenges to cocoyam promote their industrial applications. consumption: Facts Other delimiting factors to the against myths growth and promotion of cocoyam Crucial to the optimal food are the laborious and time consuming use of starchy crops is an in-depth preparation methods for traditional understanding of their processing dishes, and the general lack of diversity characteristics, especially during in existing food use (Acheampong heating and cooling (Chatakanonda et al., 2015; Ramanatha et al., 2010). et al., 2003; Tananuwong and Reid, Culturally acceptable and accustomed 2004). Such knowledge, promotes the cocoyam dishes in the sub-region exploitation of the industrial applications include ‘fufu’, and ‘ampesi’, as well of the crops and the development of as delicacies such as ‘ɛtↄ’ (eto), new food products. Data on cocoyam ‘mpotↄmpotↄ’ (mpotompoto/mpehuu), is scarce, and the available information ‘koliko’ (fried chips), fried crisps and is sparsely distributed. In particular, ‘ↄgↄↄ’ (ogoo) (Acheampong et al., there is paucity of information on the 2015; Doku, 1966; Ramanatha et al., intricate molecular properties of its 2010). All have difficult-to-follow and cormels, flours, and starches during time-consuming recipes, and generally heating and cooling. the dishes cannot be stored for more Moreover, studies have shown than 24 hours under room conditions non-uniformity in the colour nuances with their original qualities maintained. between the apical, middle, and Plates 2.0 – 7.0 and Figures 2.0 – 6.0, distal portions of cormels within a respectively show samples (pictures) given cocoyam variety (Sefa-Dedeh and the process flows for traditional and Agyiri-Sackey, 2002; Boakye preparation of these dishes. et al., 2017). This variability in the

250 Enhancing the food applications of cocoyam

Plate 2.0: Cocoyam ampesi served with tomato sauce.

Plate 3.0: Enhancing the food applications of cocoyam 251

Coc

Figure 2.0: Process flow for the preparation of cocoyam “ampesi” and eto (“Ԑtͻ”) 252 Enhancing the food applications of cocoyam

Figure 3.0: Process flow for preparation of cocoyam “fufu” Enhancing the food applications of cocoyam 253

Plate 4.0: A ball of cocoyam fufu. This is usually served with soup as a main meal.

Figure 4.0: Process flow for preparation of “Ↄgᴐᴐ” 254 Enhancing the food applications of cocoyam

Plate 5.0: “Ↄgᴐᴐ” Top: Cocoyam in ground pepper sauce, palmoil and groundnut paste during preparation of ᴐgᴐᴐ Left: Ready-to-eat ᴐgᴐᴐ; Right: Ↄgᴐᴐ as served (garnished with roasted groundnut and avocado) Enhancing the food applications of cocoyam 255

Figure 5.0: Process flow for preparation of “mpotompoto

Plate 6.0: Mpotompoto/ Mpehuu as served: A one-pot meal from cocoyam 256 Enhancing the food applications of cocoyam

Figure 6.0: Process flow for preparation of cocoyam chips (koliko) and crisps Enhancing the food applications of cocoyam 257

Plate 7.0: Cocoyam crisps sold as snack

To mitigate this challenge, research and starches of cocoyam have also been interventions have been proposed to used in combination with wheat flour improve the local dishes for convenience to develop baked products (Ojinnaka and enhance their preparation methods, et al., 2009; Sanful et al., 2010), and as well as to develop novel dishes and the modified starch has been used in food products (Lebot, 2009; Onyeka, the development of a complementary 2014; Ramanatha et al., 2010). These (infant) gruel (Ojinnaka et al., 2013). recommendations are made more However, considering the relevant in an era of rapidly changing important role of utilization (ready dietary patterns and increased consumer markets) on crop production levels, preferences for convenience in food it would be beneficial for research preparation (Ali and Kapoor, 2010; interventions to further target the Thompson and Amoroso, 2014). This improvement of existing dishes for is heightened by the success story of convenience, as well as exploring the development and introduction of new possibilities for cocoyam food convenient ‘fufu’ (‘fufu’ powder) to applications. local and international markets Itching of the throat and stomach (Acheampong et al., 2015). discomforts upon consumption of some Innovative food ideas have focused on cocoyam dishes also limit their optimal the development of new recipes use (Sefa-Dedeh and Agyir, 2002; for house-hold preparations using Personal communication, 2014). These the cormels (Baidoo, 2014). The flours undesirable traits have generally been 258 Enhancing the food applications of cocoyam

attributed to the high levels of oxalates use of cocoyam is done alongside in the commonly consumed portions disseminating information on proper of cocoyam, namely the cormels and preparation methods and viable avenues leaves (Sefa-Dedeh and Agyir, 2002). for diversifying its food application. However, studies show that thorough New perspectives for cooking reduces the oxalate levels of cocoyam utilisation most varieties to safe levels, where Similar to many other food crops, the discomforts are generally not the optimal utilization of cocoyam experienced (Doku, 1966; Sefa-Dedeh is, to a large extent, dependent on and Agyir-Sackey, 2004; Ramanatha et the practicality of adopting modern al., 2010). techniques to predict processing Traditional taboos, prejudices, characteristics, and to evaluate on-line and myths surrounding the production, quality parameters in the food industry. preparation, and consumption of New trends in industrial food use require cocoyam dishes further hinder their such techniques to be rapid, and non- utilization. A number of these exist destructive, with short, or no sample across the West African region. preparation, and have the efficiency In Nigeria, it is considered a poor to measure a wide range of attributes person’s crop (Onyeka, 2014), in La concurrently. Advanced spectroscopy Cote d’Ivoire it is food of the gods, has been largely explored in this wise, and its major dish, fufu, should only be in food research (Feng and Sun, 2012). eaten by an entire neighbourhood, and Prominent among such techniques are never by a single household (Personal the hyper – and multi-spectral imaging communication, 2017). In Ghana, it is and spectroscopy technologies, and presumed to be associated with piles Nuclear Magnetic Resonance (NMR) (Personal communication, 2014). relaxometry (Feng and Sun, 2012; Efforts to dissuade the population from Frosch et al., 2011; Huang et al., 2014; such prejudices through educational Tananuwong and Reid, 2004). campaigns could significantly influence Both technologies have been the food use of the crop. It is worth successfully employed in studying mentioning that some of the myths may the prospective food application of require scientific studies to otherwise cocoyam to promote its industrial use. confirm or disprove them. Multispectral imaging was used to It is therefore imperative that simulate on-line tests for determining concerted efforts to promote the food Enhancing the food applications of cocoyam 259

physicochemical characteristics of versatile with no identified on-line raw and cooked cormels (Boakye process complications. The relatively et al., 2017). NMR relaxometry good digestibility of the cormels analysis further provided in-depth also provides new possibilities for its understanding to the gelatinization exploration in novel food applications. characteristics of the cormels of It is proposed that studies on the two commercial cocoyam varieties glycemic indices of the commercial (Boakye et al., 2017; Gudjonsdottir varieties should be conducted to better et al., 2016), complementing the situate the nutritional value of the microstructural study of the roots by cormels, starches, and flours, towards Sefa-Dedeh and Agyiri-Sackey (2002). their optimum exploration in diets for The findings from the studies discredit vulnerable groups. the common notion that the commercial Additionally, there is a need white variety (mankanifufuo) is for further studies on the influence, if inferior to the red (mankanikͻkͻͻ) any, of geographical location, season, because of its undesirable colour maturity, and storage on the nutritional, properties for use in fufu preparation. physicochemical, functional, and The findings will further aid processor sensorial characteristics of the selection of varieties and processing commercial cocoyam varieties. The conditions, depending on the end-use, information would help processors as well as enhance its industrial food make informed decisions on the needed applications. However, the vast genetic modifications of processing protocols, diversity (Stevens, 2012; FAO, 2013; and quality assurance systems with CABI, 2014), and varied processing respect to raw materials in the industrial characteristics of the species, demands application of the crop. further detailed studies of most (if not The existing traditional cocoyam all) released, and commercial landraces dishes further present an unexplored for optimum food application.The way, which when improved for successful characterization of the convenience in preparation and use, processability and physicochemical could rekindle their preparation and properties of the cormels, flours, and consumption in urban and peri-urban starches of the commercial varieties of settlements, and further open new cocoyam provides further information in markets via supermarket chains. The support of their suitability for increased authors explored the development of a and diversified food use. The crop is convenient form of a traditional dish, ɛtↄ 260 Enhancing the food applications of cocoyam

(Boakye et al., 2016). The investigation prepare (Plate 8.0b), compared to the successfully resulted in an updated approximately two hours needed for the traditional delicacy (Ԑtᴐ-mix; Plate 8.0) traditional recipe (Figure 2.0 above). that requires less than 10 minutes to

Plate 8.0a: Reconstituted convenient ԑtↄ-mix; left picture is ԑtↄ from flour pre-treatment method 2, right picture is ԑtↄ from flour pre-treatment method 1 Enhancing the food applications of cocoyam 261

Plate 8.0b: Preparation steps for the developed (convenient) “Ԑtᴐ-mix”

An in-house consumer evaluation of the reconstituted ɛtↄ-mix with 51 assessors showed high consumer acceptance for all evaluated attributes relative to a control using the traditional recipe. The findings of the consumer assessment is presented in Figure 7.0.

Figure 7.0: Mean consumer scores for degree of likeness of εtↄ samples Bars represent means of consumer acceptance for various attributes. Different super- scripts indicate significant difference between samples within each sensory attribute with a level of significance set to p < 0.05. The overall acceptance scale ran from a score of 1 (Dislike extremely), through 5 (Neither like nor dislike), up to 7 (Like extremely). 262 Enhancing the food applications of cocoyam

These results, coupled with the ԑtↄ.Moreover, the use of cocoyam flour success of the convenient cocoyam fufu in new food sectors has been established. flour, confirms the potential commercial Studies for the development of products viability of improved cocoyam for the baby-food industry, have resulted dishes. It is, however, recommended in the development of protein-rich, and that further comparative studies are energy-dense ready-to-prepare infant conducted on the physicochemical, gruels (sample; Plate 9.0), using locally and sensorial properties of flours from available ingredients and adaptable cormels of different maturity and process technologies (Boakye, 2017). storage durations, to identify the most The gruels had unique organoleptic appropriate conditions for optimal, attributes, and showed high consumer and consistent product quality prior to acceptance from the initial survey, prior commercialisation of the convenient to trained panel descriptive tests.

Plate 9.0: Cooked ready-to-prepare complementary (infant) gruels developed from cocoyam flour

Consumer detection of mouth-coating, further confirming the commercial an undesirable attribute in infant viability of the convenient gruels. foods, was also very low. Consumers’ Extrusion cooking and drum- willingness to feed babies with the drying are high-end technologies, which developed gruels was very high are widely employed in the production compared to a commercially available, of convenience foods including snacks ready-to-prepare gruel used as control, and ready-to-eat infant foods (Tiwari Enhancing the food applications of cocoyam 263

and Jha, 2017; Laryea et al., 2017). Acknowledgement Such technologies could be explored The authors are grateful to the DANIDA to further expand the use of cocoyam “Strengthening Root and Tuber Value in other food sectors such as the global Chains Project” implemented by snack industry, where its use is almost Kwame Nkrumah University of Science non-existent. and Technology for the financial support Therefore, there are good and to Mr. Emmanuel Nkrumah and prospects for the utilisation of cocoyam Mr. Enoch Aryeetey for the technical in new food sectors, as well as use of the assistance on the imaging. versatility of the crop to update existing food dishes to suit current market demands. The potential for tapping into the unique organoleptic properties of cocoyam cormels in new food applications is also evident. Identified technologies such as the Nuclear Magnetic Resonance relaxometry, and Multispectral Imaging could be further exploited for optimum food use of the crop. Extrusion cooking and drum- drying are also valuable processing technologies to diversify and promote cocoyam products. Thus, further research work should be performed to explore the applications of cocoyam in new food industrial sectors to provide sustainable food products and nutrition security. 264 Enhancing the food applications of cocoyam

REFERENCES

Ali, J., and Kapoor, S. (2010). Buying behaviour of consumers for food products in an emerging economy. British Food Journal, 112(2), 109–124. Retrieved from http:// doi.org/10.1108/00070701011018806 Baidoo, F. (2014). CRI introduces new cocoyam varieties, recipes. Available at www. graphic.com.gh Bermejo, H., and León, J. (Eds.). (1994). Neglected crops: 1492 from a different per- spective. Rome, Italy: Food and Agriculture Organization of the United Nations Boakye, A. A., Wireko-Manu, F. D., Oduro, I, Ellis, W. O., Gudjonsdottir, M. and Chronakis, I. (2018). Utilizing cocoyam (Xanthosoma sagittifolium) for food and nutrition security, a review. Food Science and Nutrition (In press) Boakye, A. A., Gudjonsdottir, M., Skytte, J. L., Chronakis, I., Wireko-Manu, F. D., and Oduro, I. (2017). Characteristics of red and white varieties of Xanthosoma sagit- tifolium roots during cooking, using physicochemical analysis, uniaxial compres- sion, multispectral imaging and low field NMR spectroscopy. Journal of Food Science and Technology. 54(9), 2670-2683. DOI: 10.1007/s13197-017-2704-7 Boakye A. A. (2017). Characterisation of cocoyam (Xanthosoma sagittifolium) for increased food use. A thesis submitted to the Department of Food Science and Technology, Kwame Nkrumah University of Science and Technology in partial fulfilment of requirements for Doctor of Philosophy Award in Food Science and Technology. Boakye, A. A., Kissi, A. K., Wireko-Manu, F. D., Chronakis, I., Guðjónsdóttir, M., and Oduro, I. (2016). Enhancing the food utilization of cocoyam: Development of Ԑtɔ-mix. Poster presented at World congress on root and tuber crops, Nanning Guangxi, China. CABI (2014). Invasive species compendium. Xcsconsulting. Com.Au, pp 4066. Retrieved from http://www.xcsconsulting.com.au/pdf/Vespula germanica.pdf Chatakanonda, P., Dickinson, L. C. and Chinachoti, P. (2003). Mobility and distribution of water in cassava and potato starches by 1 H and 2 H NMR. Journal of Agricul- tural and Food Chemistry, 51, 7445–7449 Crop Trust. (2010). Edible aroid conservation strategies. Technical Report. 67. Retrieved from https://www.croptrust.org/wp-content/uploads/2014/12/EdibleAroids-Strate- gy-FINAL-13Jan10.pdf Enhancing the food applications of cocoyam 265

Chukwu, G. O., Ekwe, K. C. and Anyaeche, S. (2008). Cocoyam production and usage in Nigeria. National Root Crops Research Institute (NRCRI) News Bulletin, 1, 2. Dapaah, H. and Sam, J. (2009). Final West African Agricultural Productivity Pro- gramme (W A A P P) Baseline Survey Report, Ghana. Retrieved from http://www. waapp.o rg.gh/waappmedia/reports/10-waapp-baseline-survey-report-ghana- waapp-1a/file Doku, E. V. (1966). Root crops in Ghana. Ghana Journal of Science, 6(1 and 2), 15–36. Retrieved from gains.org.gh/articles/gjs_v6_1-2_p15_36.pdf Ekwe, K., Nwosu, K., Ekwe, C. and Nwachukwu, L. (2009). Examining the underexploit- ed values of cocoyam (Colocasia and Xanthosoma spp.) for enhanced household food security, nutrition and economy in Nigeria. In: Jaenicka H., Ganry J., Zele- don Hoeschle I. and Kahara R. (Eds.). Proceedings of the international sympo- sium on underutilized plants for food security, income and sustainable develop- ment. Acta Horticulture, 806, 71–78. Falade, K. O. and Okafor, C. A. (2013). Physicochemical properties of five co- coyam (Colocasia esculenta and Xanthosoma sagittifolium) starches. Food Hydrocolloids, 30(1), 173–181. Retrieved from http://doi.org/10.1016/j.food- hyd.2012.05.006 Falade, K. O. and Okafor, C. A. (2014). Physical, functional, and pasting properties of flours from corms of two cocoyam (Colocasia esculenta and Xanthosoma sagit- tifolium) cultivars. Journal of Food Science and Technology, 52(6), 3440–3448. Retrieved from http://doi.org/10.1007/s13197-014-1368-9 FAO (2013). FAO statistical yearbook. World food and agriculture. Food and Agricul- ture Organization of the United Nations, Rome, Italy Guðjónsdóttir, M., Boakye, A.A., Wireko-Manu, F.D., Chronakis, I., and Oduro, I. (2016). Characterization of red and white cocoyam roots, flours and starches during heat- ing by low field NMR In: Proceedings of the XIII International Conference on the Applications of Magnetic Resonance in Food Science, Publisher: IM Publications, pp.49-53 DOI: 10.1255/mrfs.10 Laryea, D., Wireko-Manu, F. D. and Oduro I. (2017). Effect of drum drying on the co- lour, functional and pasting properties of sweetpotato-based complementary food. American Journal of Food Science and Technology, 5(5), 210-219 DOI: 10.12691/ajfst-5-5-7 Lawal, O. S. (2004). Composition, physicochemical properties and retrogradation char- acteristics of native, oxidised, acetylated and acid-thinned new cocoyam (Xan- thosoma sagittifolium) starch. Food Chemistry, 87(2), 205–218. Retrieved from http://doi.org/10.1016/j.foodchem.2003.11.013 Lawal, O. S. (2005). Studies on the hydrothermal modifications of new cocoyam 266 Enhancing the food applications of cocoyam

(Xanthosoma sagittifolium) starch. International Journal of Biological Mac- romolecules, 37(5), 268–277. Retrieved from http://doi.org/10.1016/j .ijbio- mac.2005.12.016 Lawal, O. S., Lechner, M. D., Hartmann, B. and Kulicke, W. M. (2007). Carboxymethyl cocoyam starch: Synthesis, characterisation and influence of reaction parame- ters. Starch – Stärke, 59(5), 224–233. Retrieved from http://doi.org /10.1002 star. 200600594 Lebot, V. (2009). Tropical root and tuber crops: Cassava, sweet potato, yams and aroids. Crop Production Science in Horticulture. CABI Publishing. UK Ojinnaka, M. C., Akobundu, E. N. T. and Iwe, M. O. (2009). Cocoyam starch modifi- cation effects on functional, sensory and cookies qualities. Pakistan Journal of Nutrition, 8(5), 558–567. Retrieved from http://pjbs.org/pjnonline/fin1178.pdf Ojinnaka, M. C., Ebinyasi, C. S., Ihemeje, A. and Okorie, S. U. (2013). Nutritional evaluation of complementary food gruels formulated from blends of soybean flour and ginger modified cocoyam starch. Advance Journal of Food Science and Tech- nology, 5(10), 1325–1330. Retrieved from http://www.maxwellsci.com/print/ajfst/ v5-1325-1330.pdf Onyeka, J. (2014). Status of cocoyam (Colocasia esculenta and xanthosoma spp.) in West and Central Africa : Production, household importance and the threat from Leaf Blight. Lima (Peru). CGIAR Research Program on Roots, Tubers and Banan- as (RTB). Available Online at www.rtb.cgiar.org Opara, L. U. (2003). Edible Aroids: Post harvest operations. D. Mejía, (Ed.). Food and Agriculture Oranisation of the United Nations. Opoku-Agyeman, M. O., Bennet-Lartey, S. O. and Markwei, C. (2004). Agro-morpho- logical and sensory characterization of cocoyam (Xanthosoma sagittifolium L) (Schott) germplasm in Ghana. Ghana Journal of Agricultural Science, 37, 23–31. Quaye, W., Adofo, K. and Nimoh, F. (2010). Socioeconomic survey of traditional commercial production of cocoyam and cocoyam leaf. African Journal of Food, Agriculture and Nutrition Development, 10(9), 4060–4078. Ramanatha, R. V., Matthews, P. J., Eyzaguirre, P. B. and Hunter, D. (2010). The global diversity of taro: Ethnobotany and conservation. H. D. Ramanatha Rao V., Mat- thews Peter J., Eyzaguirre Pablo B., (Eds.). Rome, Italy: Bioversity International. Retrieved from http://www.bioversityinternational. org/uploads/tx_news/The_ global _diversity_of_taro__ethnobotany_and_conservation_1402.pdf Sanful, R. E. and Darko, S. (2010). Production of cocoyam, cassava and wheat flour composite rock cake, Pakistan Journal of Nutrition, 9(8), 810–814. Sefa-Dedeh, S. and Agyir-Sackey, E. K. (2002). Starch structure and some properties of cocoyam (Xanthosoma sagittifolium and Colocasia esculenta) starch and ra- Enhancing the food applications of cocoyam 267 phides. Food Chemistry, 79(4), 435–444. Retrieved from http://doi.org/10.1016/ S0308-8146(02)00194-2 Sefa-Dedeh, S. and Agyir-Sackey, E. K. (2004). Chemical composition and the effect of processing on oxalate content of cocoyam Xanthosoma sagittifolium and Coloca- sia esculenta cormels. Food Chemistry, 85(4), 479–487. Retrieved from http://doi. org/10.1016/S0308-8146(02)00244-3 Stevens, P. F. (2012). Angiosperm Phylogeny Website. Version 13. St Louis, MO: Missou- ri Botanical Garden, University of Missouri Tananuwong, K. and Reid, D. S. (2004). DSC and NMR relaxation studies of starch-wa- ter interactions during gelatinization. Carbohydrate Polymers, 58(3), 345–358. Retrieved from http://doi.org/10.1016/j.carbpol.2004.08.003 Thompson, B. and Amoroso, L. (Eds.). (2014). Improving diets and nutrition: Food- based approaches. Food and Agriculture Organisation. Retrieved from http:// www.cabi.org/ cabebooks /ebook/20143140822 Tiwari, A. and Jha, S. K. (2017). Extrusion Cooking Technology: Principal Mechanism and Effect on Direct Expanded Snacks – An Overview. International Journal of Food Studies, 6, 113–128 Vasantha, S., Vijaylakshmi, S. and Kiran, P. (2015). Review on impact of changing life- styles on dietary pattern. International Journal of Current Research and Academic Review, 3, 135–147 268

Orange-fleshed sweetpotato composite bread: The nutritional and economic potential

Francis Kweku Amagloh Department of Food Science and Technology, University for Development Studies, Tamale, Ghana Email: [email protected]

Abstract This chapter will consider the three As an effort to complement the vitamin A recipes of composite bread: vitasugar, supplementation initiative in Ghana for vitabutter and vitatea developed from addressing vitamin A deficiency, both about 46% OFSP puree and 54% wheat local and international developmental flour. Consumer acceptance studies of partners are promoting the inclusion the OFSP-based bread recipes and their of orange-fleshed sweetpotato (OFSP) conventional 100% wheat flour types in the diet of Ghanaians. However, will be discussed. The contribution the extent of OFSP adoption may be of the vitabread recipes to intake of limited owing to the availability of other dietary vitamin A and benefit cost ratio root and tuber crops in the country. A (BCR) considering the baker as the sustainable approach to ensure OFSP value chain actor will also be presented. consumption by Ghanaians is through The overall degree of liking for the value addition by including it to refine vitabread recipes (vitasugar_no sugar existing food recipes in Ghana. Bread & vitasugar_with sugar) and wheat is becoming a major staple in Ghana (white) bread was not significant (p = enjoyed by both children and adults. 0.63). A paired preference assessment In a previous study conducted in four of vitabutter and vitatea against their regions: Greater Accra, Ashanti, Upper conventional bread types showed that East and Northern in Ghana, out of OFSP-wheat composite recipes were the 649 (373 male, and 276 female) of most preferred by at least 77% (p<0.05) the respondents, 97% indicated they of consumers (n = 310) for appearance, consumed bread. Thus, composite aroma, sweetness and overall degree bread of wheat and OFSP has the of likeness. Vitabread could be a good potential to improve and create wealth. source of dietary vitamin A for children Orange-fleshed sweetpotato composite bread 269

as it met 17% of the recommended 300 deficient, with 35% of them classified μg RAE/day based on estimated daily as severe (serum retinol <10 μg/dL) serving size of 26 g. Based on average (World Health Organization, 2009). daily intake by the lactating mothers for The Report further showed that women vitabutter (247 g), and for vitatea (196 of childbearing age (15 to 49 yr) stricken g), the recipes could respectively meet with night blindness are about 1.5 times 21% and 12% of the Recommended high relative to the maximum cut-off of Dietary Allowance of vitamin A (1300 5% for classification as a public health µg RAE/day). The BCR for vitasugar issue. Owing to this, efforts to reduce with sugar recipe was 1.08 indicating the prevalence of VAD is increasingly profitability compared to 0.97 for gaining attention in Ghana. Local and conventional sugar bread. OFSP could international developmental partners be composited with wheat flour to are promoting the inclusion of OFSP in bake sugar, butter, and tea bread; and the traditional household-level dishes in will contribute significant amount of Ghana, as have been reported elsewhere dietary vitamin A to support efforts in in Africa (Kapinga et al., 2005). For addressing vitamin A deficiency in low- instance, there has been some evidence income countries. Also, the BCR value of improved vitamin A status of young for the vitasugar recipes predicts that it South African children after they were would be more profitable for bakers if fed with mashed OFSP (van Jaarsveld they adopt the vitabread recipes in their et al., 2005). business. The extend of OFSP adoption to improve vitamin A nutrition among the Introduction vulnerable groups in Ghana, may be Orange-fleshed sweetpotato (OFSP) is limited owing to the availability of other fast becoming an important root crop, root and tuber crops and bananas such with sufficient amount of β-carotene, as yam, cocoyam, cassava and plantain. a provitamin A, capable of addressing If OFSP is subjected to the traditional the nutritional needs of lactating methods of preparation as applied to women and children under five years these food crops, it would not deliver in the sub-Sahara Africa (Low, Walker, the product consistency and palatability & Hijmans, 2001). The prevalence of Ghanaian consumers have associated subclinical vitamin A deficiency (VAD) with those food types. Therefore, a in Ghana is high; almost three-quarters sustainable approach to ensure OFSP of children under age five being consumption by Ghanaians is through 270 Orange-fleshed sweetpotato composite bread

value addition by including it in composition of the flour and the refining existing food recipes in Ghana. ingredients used as; tea bread butter Product refinement by incorporating bread, sugar bread, and brown bread biofortified food crops, example, (Ellis et al., 1997). All the bread types OFSP, into existing local recipes has the are made from similar ingredients potential to increase the dietary intake except for the quantities involved. For of essential micronutrients. Therefore, instance, in sugar bread, there is reduced refining existing food recipes such as fat and a high concentration of sugar bread will not only deliver vitamin A to (about 14%) (Ellis et al., 1997). The a large number of people but also will high cost of sugar importation increases be readily acceptable. Earlier works the cost of production; thereby reducing indicates that Ghanaian consumers the profit margins of bakers while some would accept the OFSP-based bread consumers raise health concerns about when introduced into the Ghanaian taking in refined white sugar products. markets (Bonsi, Chibuzo, & Zibawa, In this chapter, we will consider 2014; Bonsi et al., 2016). consumer three recipes of composite Bread is becoming a major staple bread: vitasugar, vitabutter and vitatea. in Ghana, enjoyed by both children Consumer acceptance studies of the and adults (Bonsi et al., 2014; Bonsi et OFSP-based bread recipes and their al., 2016; Ellis et al., 1997; Komlaga, conventional 100% wheat flour types Glover-Amengor, Dziedzoave, & will be evaluated. The contribution of Hagan, 2012). However, the breads the vitabread recipes to intake of dietary found in the Ghanaian markets are vitamin A and benefit cost ratio (BCR) whole wheat-based; making the breads considering the baker as the value chain relatively expensive. This is because actor will also be considered. the basic raw material in bread making, Bread consumption wheat, is imported (Oluwalana, survey responses from Malomo, & Ogbodogbo, 2012) and four regions in Ghana cannot be cultivated due to unfavourable In a cross-sectional survey conducted climatic conditions in tropical countries on bread consumption in four regions like Ghana. It is therefore not surprising of Ghana: Ashanti, Greater Accra, that in 2015, Ghana recorded its highest Northern and Upper East in Ghana, import of wheat about 788000 MT out of 649 (373 male and 276 female) (Barrientos & Soria, 2016). In Ghana, respondents, 97% indicated they bread is categorized based upon the Orange-fleshed sweetpotato composite bread 271

consumed bread, irrespective of type, Region, and 3.70 kg/capita/year nutritional or sensorial quality (Youngs, 1972). (Fig 1). The survey also showed The findings further elaborated that bread consumption was similar that about 6.4%, 3.2%, 9.8% and 2.1% in the four regions surveyed. All the more males than females consumed respondents in the Greater Accra and bread in Greater Accra, Ashanti, Upper Ashanti regions consumed bread while East and Northern Regions, respectively. about 96% and 99% of respondents in This shows that a remarkably high the Upper East and Northern Regions percentage of Ghanaians consume respectively did consume bread. This bread as reported by other researchers was contrary to earlier works published (Bonsi et al., 2014; Bonsi et al., 2016; in 1972 that showed that marked Ellis et al., 1997; Komlaga et al., 2012), differences in bread consumption in suggesting a very high market potential Accra (21.20 kg/capita/year) compared for bread. with 0.37 kg/capita/year for Northern

Fig. 1: Response per region and gender to bread consumption

Consumers’ willingness to expressed, without knowledge of its buy OFSP composite bread nutritional quality, their willingness to Pertaining to the OFSP composite buy the new composite bread. bread, the survey revealed (Fig. 2a) Generally, the number of males who that about 83% of the total number of were willing to buy the new product was respondents in all the four locations about 1.4% times higher than females. 272 Orange-fleshed sweetpotato composite bread

On regional basis, the willingness to to buy OFSP-based composite bread purchase the OFSP-based bread was in Northern and Upper East regions observed to be slightly higher for Upper could be due to the awareness creation East and Northern regions (averagely, activities on orange-fleshed sweetpotato 95%) compared with 85% for Greater being implemented in northern Ghana Accra, and 47% for the responses by local and international development obtained for the Ashanti Region. The partners. relatively high responses for willingness

70 Yes (%) No (%) 60

50

40

30

20

10

0

Response not based on nutritional awareness (%) awarenessbased on nutritional Response not Male Female Male Female Male Female Male Female Accra (n=47) Ashanti (n=62) Northern (n=152) Upper East (n=388) Region and gender

Fig. 2a: Responses per region and gender on willingness to buy OFSP composite bread not based on awareness of nutritional benefits.

It is noteworthy that in the Ashanti expressed willingness to buy the Region where the initial responses product indicating generally that more for willingness to buy was similar for males patronise bread in Ghana than both No and Yes responses, there was females. Thus, the processing OFSP 97% increase in the Yes responses into bread will would be the panacea when respondents were made aware to the reported low patronage of of the nutritional importance the sweetpotato cultivars in Ghana due OFSP bread (Fig. 2b). From a regional to their sweetness and strong flavours perspective, consumers’ willingness (Baafi et al., 2015). Also, utilisation of to buy the new product based on its OFSP as bread may have the potential nutritional value was above 92%. to improve the low preference of this About 15% more males than females cultivar by men (Tomlins et al., 2004). Orange-fleshed sweetpotato composite bread 273

70 Yes No 60

50

40

30

20

10

0 Male Female Male Female Male Female Male Female

Response based on nutritional awareness(%) on nutritionalResponse based Accra (n=47) Ashanti (n=62) Northern (n=152) Upper East (n=388) Region and Gender

Fig. 2b: Responses per region and gender on willingness to buy OFSP composite bread based on awareness of nutritional benefits

Preparation of OFSP-wheat following. The OFSP storage roots flour composite bread were sorted the OFSP roots to remove Three recipes of OFSP puree-wheat weevil infested ones, washing them composite bread have been developed with tap water, peeling and boiling for by refining existing bread recipes 30 minutes. The boiled roots were then for sugar, butter and tea bread types pounded into puree after cooling at available on the Ghanaian market (Ellis room temperature. et al., 1997). For the vitasugar, two The difference between vitabutter recipes were developed, one containing bread and vitatea bread developed sugar (vitasugar_with sugar), and were the quantity of margarine in the vitasugar_no sugar, which did not have dough and their shapes after moulding refined sugar added, and the percentage per Ghanaian style for these bread of OFSP puree incorporation was 42% types (Fig. 3b and Plates 1 & 2). The (Fig. 3a) by refining existing recipe for variation between the proportion of sugar bread. For vitabutter and vitatea yeast used for vitasugar compared with bread recipes (Fig. 3b), the OFSP puree vitabutter and vitatea was to to speed incorporation was at 46%. up the proofing time. The incorporation The puree was prepared using of puree for the developed Vitasugar, household-level technology as 274 Orange-fleshed sweetpotato composite bread

Vitabutter and Vitatea recipes were recipes published by Bonsi et al., (2014) 44% and 53%increase over the earlier and Bonsi et al., (2016), respectively.

Fig. 3a: Flowchart of Vitasugar bread (Plate1)

Orange-fleshed sweetpotato composite bread 275

Fig 3b: Flowchart of vitabutter and Vitatea bread types (Plates 1&2)

The higher incorporation level in the Consumer acceptability of rate of puree in the vitabread types in OFSP composite bread this chapter suggests more profitability Consumer acceptance test was conducted as the proportion of wheat has been on the vitasugar and the vitasugar_no reduced. This would help reduce sugar, the composited bread of OFSP the importation of wheat for bread puree and wheat flour, as well as existing sugar bread based on 100% wheat production and create high demand flour. Generally, all the bread samples for OFSP roots that are locally grown evaluate were highly preferred in all in most regions in Ghana. Also, these the attributes investigated: appearance, bread types could be a significant dietary aroma and overall acceptability (Table source of vitamin A. Thus, the high 1). Using a hedonic scale ranging from consumption of bread by Ghanaians 1 as extremely dislike to 5 as like (Bonsi et al., 2014; Bonsi et al., 2016; extremely, all the sensory scores were Ellis et al., 1997; Komlaga et al., 2012), above 4.1. This finding indicates that would make the Vita bread recipes very bread has become a significant portion crucial in addressing VAD in Ghana. of the Ghanaian diet, supporting earlier studies conducted in Ghana (Bonsi et al., 2014; Bonsi et al., 2016; Ellis et al., 1997; Komlaga et al., 2012). However, vitasugar and existing sugar bread were evaluated different between male and female respondents (p=0.028) for appearance. 276 Orange-fleshed sweetpotato composite bread

Table 1: Consumer preference per gender of vitasugar bread types and existing sugar bread

Sensory attributes Gender Bread type Appearance Aroma Overall degree of liking Vitasugar 4.33±0.10a 4.31±0.12a 4.35±0.11a Male Vitasugar_no sugar 4.49±0.10ab 4.15±0.12a 4.20±0.11a Sugar bread 4.65±0.10b 4.30±0.12a 4.45±0.11a Vitasugar 4.63±0.15b 4.37±0.17a 4.46±0.16a Female Vitasugar_no sugar 4.40±0.15ab 4.50±0.17a 4.39±0.16a Sugar bread 4.24±0.15a 4.21±0.17a 4.46±0.16a P-value 0.028 0.316 0.805 Values (mean ± SEM) in the same was used to assess the opinion of 100 column with unlike superscripts bread consumers on the sweetness are significantly different (p>0.05). intensity of vitasugar, vitasugar_no Hedonic scale ranging from 1 = sugar and existing 100% sugar bread on extremely dislike to 5 = like extremely. the Ghanaian market. About that 70% The similar preference of of the respondents indicated that the vitasugar_no sugar sample as the other sweetness of the three bread samples two samples indicates that the addition was just about right (Fig. 4). Female of refined sugar as an ingredient suring respondents recorded 9.7%. 4.6% and bread baking is not necessary. This is 4.5% more than males respectively due the conversion of starch to simple for vitasugar, vitasugar_no sugar and sugars, maltose, when the storage existing sugar bread. This supports roots of sweetpotato were subjected earlier suggestion the natural sweetness to temperatures above 65ºC (Deobald, intensity of sweetpotato is sufficient to Hasling, Catalano, & McLemore, 1969; bake bread. Thus, using the OFSP puree, Ridley, Kim, Heenan, & Bremer, 2005; refined sugar can be eliminated, and this Walter, Purcell, & Hoover, 1976). has both health and cost implications as Apart from the appearance with gender well. differences as mentioned above, both aroma and overall degree of liking were not influenced by gender, indicating that both Ghanaian males and females have similar preference for all bread types.The just-about-right (JAR) scale Orange-fleshed sweetpotato composite bread 277

Fig 4: Consumer sensory evaluation on sweetness using Just about right scale A paired preference test carried of appearance, aroma, sweetness and out by 300 panellists revealed that overall degree of liking (Fig. 5 & 6). vitabutter bread and vitatea bread were The preference for vitabutter bread was most preferred over the conventional about two to three times more than that 100% wheat flour bread types in terms of the existing butter bread.

300 250 Vitabutter bread conventional butter bread 200 150 100 Preference counts 50 0 Appearance Aroma Sweetness Overall degree of likeness Sensory attributes

Fig. 5: Preference for Vitabutter bread as compared to existing butter bread on the Ghanaian market. Horizontal bar (----) represents Expectedly, the preference for minimum threshold for difference vitatea bread was three to four times in preference; bars above threshold more than that of the conventional represent most preferred bread type. tea bread, as the vitatea bread had a 278 Orange-fleshed sweetpotato composite bread

relatively high sweetness intensity. color, flavour and sweetness of OFSP The higher consumer preference for (Leighton, 2007), supporting the earlier Vitabutter bread and Vitatea bread assertion that Ghanaian population than conventional 100% wheat flour irrespective of their gender, would bread types may be due to the inherent prefer OFSP-based bread recipes.

Fig. 6: Preference of Vitatea bread as compared to conventional tea bread Horizontal bar (----) represents minimum threshold for difference in preference; bars above threshold represent most preferred bread type.

Thus, if the vitabread recipes are Contribution to dietary vitamin promoted to the general public of its A intake from the OFSP-based potential health benefits (vitamin A composite bread and wheat only bread and no refined sugar added), they may Fifty lactating mothers at Dungu in the have higher market potential than the Tamale Metropolitan District, Northern existing bread types. As stated earlier, Region, were served with Vitabutter consumers indicated that would buy bread and Vitatea bread. Serving sizes the vitabread recipes if the nutritional of Vitabutter bread ranging from 236 benefits are made knownFig. ( 2a & g – 520 g and Vitatea bread of weight 2b). ranging from 178 g – 527 g were given to these lactating mothers to consume. Left overs were weighed to get the actual bread intake. This was done to Orange-fleshed sweetpotato composite bread 279

determine the vitamin A contribution of bread and vitatea bread were analysed the vitabutter bread and vitatea bread to by the Food and Nutrition Evaluation the Recommended Dietary Allowance Laboratory, Nairobi, Kenya and used for for vitamin A, which is 1300 µg RAE/ calculating the vitamin A contribution day for lactating mothers. The trans of these bread types. β-carotene content of the vitabutter

300 n=24 p=0.18 250 n=26

200

150

100

Amount of breadconsumed (g) 50

0 Vitabutter Vitatea OFSP-based bread type Fig. 7: Mean trans β-carotene content of OFSP-based bread types Bars are mean intake ± standard deviations.

Fig. 8: Mean dietary intake of OFSP-based bread by lactating women Bars are mean intake ± standard deviations. 280 Orange-fleshed sweetpotato composite bread

The vitabutter bread had significantly highest daily requirement, indicates higher trans-β-carotene content (1.3 that it would be significant source of times, p=0.01) than that in vitatea bread dietary vitamin A for children, whose (Fig. 7). However, the mean intake of requirement is about a quarter of that of bread two bread types by lactating lactating mothers. Therefore, initiatives mothers were 247.10±144.87 (g) for aimed at improving the vitamin A status vitabutter bread, and 195.60±122.76 of vulnerable groups in Ghana using (g) for vitatea, but was not statistically food based measures should adapt these different (p=0.18). vitabread recipes. The OFSP contribution of trans Benefit Cost Ratio analysis β-carotene in vitabutter bread was on composite bread 1333 µg/100 g and 985 µg/100 g in Importation of wheat flour into Ghana vitatea bread as compared to white keep rising year after year even though bread which was reported to be 260 there exist a marginal decline in some µg/100 g by Bonsi et al., (2016). Based years between 1960 to 2016 (Barrientos on the trans β-carotene level and the & Soria, 2016). Until 1999, when Ghana bread intake data, vitabutter and vitatea imported about 205,000 MT of wheat, would respectively meet 21% and 12% its annual importation of wheat was of 1300 µg/day of the Recommended below 200,000 MT. The highest import Dietary Allowance of vitamin A for of wheat was recorded in 2015 when 15 to 25 years old lactating mothers. the country import about 788000 MT. The higher trans β-carotene content Unlike sugar where steps are in the vitabutter bread than the vitatea being taken to reduce the importation is due to the higher proportion of of sugar by revamping of the Komenda vitamin A-fortified margarine used sugar factory in Ghana, wheat and for in the butter bread recipe (Fig. 3b). that matter wheat flour, has no such Also, the vitabread intake and the intervention as our climatic conditions superior preference of the vitabread are not suitable for its cultivation. It recipes compared with existing recipes has been estimated and reported by the as above-mentioned in this chapter Daily Democrat newspaper, 18th July, suggest that OFSP puree-based bread 2012 that replacing of 100% wheat could be crucial in addressing VAD flour with composite flour of wheat in Ghana. Contributing at least 12% and locally cultivated staples for flour of the daily requirements of vitamin A products can earn the country US$2 needs by lactating mothers, the group Orange-fleshed sweetpotato composite bread 281

billion annually (Djan, 2012). obviously explains why it is more Given the soaring prices for profitable venture. Therefore, bakers in wheat flour due to the high demand, Ghana could adapt to use OFSP puree and the suitable climatic conditions in baking for higher profits. for sweetpotato cultivation in Ghana, However, for the potential of the OFSP puree-based bread recipes be OFSP described in this chapter could considered as they would lead to create be realized in Ghana, there is a need employment opportunities, increase to have an all-year supply of quality income of sweetpotato farmers and storage roots. This is a major present also save some foreign currency which challenge that needs to be addressed. In scarce for the country. addition, commercial storage facilities In Ghana, bread is mostly should be introduced in Ghana as done in produced from 100% wheat flour. developed countries where sweetpotato Substituting OFSP puree with wheat are cultivated. Also, provision of flour, increased the profit margin of the irrigation facilities for planting in the baker by 92% (Low & van Jaarsveld, dry season should be considered. 2008). Vitasugar developed from about To conclude, the inclusion of 46% OFSP puree and 54% wheat OFSP puree in flour products, example flour in the current study showed a bread, will minimise the importation BCR of 1.08% indicating profitability of wheat flour and white sugar thereby compared to 0.97% for conventional lower the production cost for increased sugar bread. The recipe of vitasugar profits. Thus, composite bread of used for the BCR calculation was the wheat and OFSP has the potential to one developed with refined sugar. The stimulate economic growth, and more reduction in the quantities of wheat importantly, the vitamin A status and flour and sugar in the vitasugar recipe overall health of the populace. 282 Orange-fleshed sweetpotato composite bread

REFERENCES

Baafi, E., Manu-Aduening, J., Carey, E. E., Ofori, K., Blay, E. T., & Gracen, V. E. (2015). Constraints and breeding priorities for increased sweetpotato utilization in Ghana. Sustainable Agriculture Research, 4(4), 1-16. doi:10.5539/sar.v4n4p1 Barrientos, M., & Soria, C. (2016). Ghana wheat import by year. Retrieved from http://www.indexmundi.com/ agriculture/?country=gh&commodity=wheat&graph=imports Bonsi, E., Chibuzo, E., & Zibawa, R. (2014). The preliminary study of the acceptability of Ghana bread made with orange sweet potato puree. Journal of Human Nutrition & Food Science, 2(5), 1045. Bonsi, E. A., Zabawa, R., Mortley, D., Bonsi, C., Acheremu, K., Amagloh, F. C., & Amagloh, F. K. (2016). Nutrient composition and consumer acceptability of bread made with orange sweet potato puree. Acta Horticulturae, 1128, 7-14. doi:10.17660/ActaHortic.2016.1128.2 Deobald, H. J., Hasling, V. C., Catalano, E. A., & McLemore, T. A. (1969). Relationship of sugar formation and sweet potato alpha-amylase activity during processing for flake production. Food Technology, 23, 826 – 829. Djan, E. O. (2012). Ghana to save US$5b from use of composite flour annually. Retrieved from http://www.ghanaweb.com/GhanaHomePage/NewsArchive/Ghana- To-Save-US-5b-From-Use-Of-Composite-Flour-Annually-245072 Ellis, W. O., Obubuafo, A. K., Ofosu-Okyere, A., Marfo, E. K., Osei-Agyemang, K., & Odame-Darkwah, J. K. (1997). A survey of bread defects in Ghana. Food Control, 8(2), 77-82. doi:http://dx.doi.org/10.1016/S0956-7135(96)00075-8 Kapinga, R., Anderson, A., Crissman, C., Zhang, D., Lemaga, B., & Opio, F. (2005). Vitamin A partnership for Africa: A food based approach to combat vitamin A deficiency in sub-Saharan Africa through increased utilization of orangefleshed sweetpotato. Chron Horticult, 45, 12-14. Komlaga, G. A., Glover-Amengor, M., Dziedzoave, N. T., & Hagan, L. L. (2012). Consumer acceptability of wheat cassava composite bread. World Rural Observation, 4(2), 78-81. Low, J., Walker, T., & Hijmans, R. (2001). The potential impact of orange-fleshed sweetpotatoes on vitamin A intake in Sub-Saharan Africa. Low, J. W., & van Jaarsveld, P. J. (2008). The potential contribution of bread buns fortified with β-carotene–rich sweet potato in Central Mozambique. Food & Orange-fleshed sweetpotato composite bread 283

Nutrition Bulletin, 29(2), 98-107. Oluwalana, I. B., Malomo, S. A., & Ogbodogbo, E. O. (2012). Quality assessment of flour and bread from sweet potato wheat composite flour blends. International Journal of Biological and Chemical Sciences, 6(1), 65-76. Ridley, S. C., Kim, M., Heenan, S., & Bremer, P. (2005). Evaluation of sweet potato cultivars and heating methods for control of maltose production, viscosity and sensory quality. Journal of Food Quality, 28(2), 191-204. doi:10.1111/j.1745- 4557.2005.00013.x Tomlins, K., Rwiza, E., Nyango, A., Amour, R., Ngendello, T., Kapinga, R., . . . Jolliffe, F. (2004). The use of sensory evaluation and consumer preference for the selection of sweetpotato cultivars in East Africa. Journal of the Science of Food and Agriculture, 84(8), 791-799. doi:10.1002/jsfa.1712 van Jaarsveld, J. P., Faber, M., Tanumihardjo, A. S., Nestel, P., Lombard, J. C., & Benadé, J. S. A. (2005). β-Carotene–rich orange-fleshed sweet potato improves the vitamin A status of primary school children assessed with the modified-relative- dose-response test. American Journal of Clinical Nutrition 81, 1080 –1087. Walter, W. M., Purcell, A. E., & Hoover, M. W. (1976). Changes in amyloid carbohydrates during preparation of sweet potato flakes. Journal of Food Science, 41(6), 1374-1377. doi:10.1111/j.1365-2621.1976.tb01175.x World Health Organization. (2009). Global prevalence of vitamin A deficiency in populations at risk 1995–2005. WHO global database on Vitamin A deficiency. Geneva, World Health Organization. Geneva, Switzerland: WHO Press. Youngs, A. J. (1972). Wheat-flour and bread consumption in West Africa: Review with special reference to Ghana. Tropical Science, 14(3), 235 – 244. 284

Shelf life extension and sensory properties of orange- fleshed sweetpotato using pre – and post-harvest techniques

Richard A. Atuna1, Edward E. Carey2, Jan W. Low3 and Francis K. Amagloh4 1Department of Biotechnology and Molecular Biology, University for Development Studies, Tamale, Ghana, [email protected] 2International Potato Center, Kumasi, Ghana, [email protected] 3International Potato Center, Nairobi, Kenya, [email protected] 4Department of Food Science and Technology, University for Development Studies, Tamale, [email protected]

Abstract seasons. Physical (weight loss, weevil Orange-fleshed sweetpotato (OFSP) damage, rot and sprout) and sensory is an important root crop capable of qualities of the roots were assessed. ameliorating vitamin A deficiency To create the wounds, 21 roots were that is a public health concern in Sub deliberately damaged using a potato Saharan Africa. However, most of the peeler; the curing treatment was OFSP cultivars have relatively short applied; and the subsequent quality shelf life largely due to improper pre- status of the roots monitored daily over and post-harvest management. In this a seven-day period post treatment. The study, two OFSP cultivars, Apomuden wound healing was scored based on and Nane, were either cured in-ground the scale: 0 = no lignification, 0.5 = by dehaulming prior to harvest or field- patchy lignification and 1= complete piled over a seven-day period to study lignification. A five point hedonic scale their responses to wound healing and ranging from 1= extremely dislike to 5= changes in dry matter content. The like extremely was used to assess the uncured treatments together with the general appearance, finger-feel firmness, sweetness and overall acceptability cured roots were stored in either sand of the boiled roots. Generally, wound box or heap for nine and eight weeks, healing ability of cultivars increased respectively in two successive farming as curing progressed until the fifth Shelf life extension and sensory properties 285

day and levelled off in both farming Introduction seasons. Field-piled curing method Orange-fleshed sweetpotato (OFSP) resulted in a significantly high (0.86) is an important root crop capable of wound healing score relative to the in- ameliorating vitamin A deficiency that ground curing (0.75) (p = 0.001) in the is a public health concern in Sub Saharan second season. Similarly, field-piled Africa (Low, Walker, & Hijmans, curing resulted in high (p = 0.020) dry 2001). The sweetpotato cultivars matter content, 24%, compared with grown in Ghana and the sub regions are in-ground curing (22%). Apomuden mostly white or cream fleshed, devoid consistently recorded significantly high of β-carotene, provitamin A. However, (p<0.05) weight loss and rots in both Apomuden, a variety in Ghana, contains farming seasons. The sand box storage significant amounts (2100-5500 µg/100 was significantly lower (p<0.05) in all g fwb) of β-carotene (Tumwegamire physical root quality except for sprouts et al., 2014) and have the potential that it had a significantly high (p<0.05) of addressing vitamin A deficiency score relative to the heap storage. All (VAD) that is a public health issue in sensory attributes had a score ranging third world countries including Ghana from 3.20 to 3.84 (farming season I) (World Health Organization, 2009). and 3.32 to 3.93 (farming season II) There have been several indicating a good consumer preference campaigns by both local and for both cultivars. Wound healing international organisations to promote ability, an indicator of good storability OFSP cultivars as a food-based approach of sweetpotato was high in field- to addressing VAD among pregnant and piled curing method and could result lactating women and children under five in better storability of roots. It also years (Kapinga et al., 2005). However, resulted in high dry matter content of this goal of promoting the use of OFSP roots, a desirable root quality trait for cultivars as food-based approach may be OFSP cultivar. The sand box storage affected due to inappropriate pre – and improved the storage properties of the postharvest management techniques. OFSP roots up to 2 months and should Sweetpotato has been reported to be recommended to farmers in Ghana, have a short shelf life due to the high and possibly in the sub region. moisture content (above70%) (Tomlins et al., 2010); the OFSP cultivars in particular are slightly higher in moisture content 60-80% (Tumwegamire et al., 286 Shelf life extension and sensory properties

2014) compared to the other cultivars. curing conditions in the tropics (Ravi Sweetpotato varieties with delicate et al., 1996). However, farmers in the skin, as is the case with the variety tropics do not practice curing although Apomuden, may be easily damaged, found to be beneficial due to lack of and may contribute to poor storability. knowledge and initial and running cost The thin delicate skin of OFSP that is of a curing facility. Dehaulming is a easily damaged has also been suggested preharvest curing technique used to for the poor storability as reported cure sweetpotato roots in-ground for elsewhere (Woolfe, 1992). Therefore, 7-14 days before harvesting and storage reducing skinning during harvesting (Ndunguru, Tomlins, Rwiza, & Westby, and transportation is important for 2000). It is achieved by removing the extending the shelf life of the crop. plant stem and canopy up to 14 days Curing of sweetpotato by holding before harvest (Tomlins et al., 2010). roots under moderate temperature (29- Earlier works suggest that in-ground 33°C) and high relative humidity (90- curing reduced skinning injury to roots 95%) for about a week before storage by 62% in a whole after 10 days of have also been reported to toughen and canopy removal before harvest (La encourage skin set in roots (Edmunds et Bonte & Wright, 1993). Field-piled is al., 2008) thereby improving storability. a form of postharvest curing method Furthermore, Curing encourages the where roots are heaped on the field formation of lignified/suberised wound covered with fresh vines for seven days periderm tissue at the wound sites before storage (Ravi et al., 1996). (Tomlins et al., 2010) which reduces Storage of agricultural produce moisture loss and microbial infection, is important in ensuring availability reducing root decay (Ravi, Aked, & of food beyond the harvest period. Balagopalan, 1996; Ray & Ravi, 2005; Traditionally, in low income countries, Sowley & Oduro, 2002). However, sweetpotato is mostly stored in shallow other factors aside from wound healing earthen piles and with associated losses through lignification are considered in between 30-35% (Jenkins, 1982). selecting cultivars with good storage A “Sand, Storage and Sprouting” potentials (Amand & Randle, 1991; (triple S) system has been developed Walter, Hammett, & Giesbrech, 1989). to preserve roots in dry cool sand, In the tropics, it is not difficult to obtain which are then planted prior to the these conditions because ambient onset of the rainy season and produce tropical conditions are similar to the sprouts for vine multiplication prior to Shelf life extension and sensory properties 287

planting (Namanda, Amour, & Gibson, maturity (Apomuden-3.5 months 2013). However, it is possible to store and Nane-4 months). Apomuden is a roots using this system for household released variety by the Crops Research consumption. Institute while Nane is a farmer cultivar In this study, two curing being evaluated for release. (dehaulming vs. field-piled) and two Curing and storage storage (sand box vs. heap) methods In-ground/curing or dehaulming (Plate for their influence on the storability two 1a) was done by removing part of the OFSP cultivars. The storability indices canopies and leaving about 30 cm of the considered were the wound healing vines from the base seven days prior to ability of cultivars during curing, harvest. In the field-piled curing (Plate physical root quality and sensory 1b) treatment, roots were carefully properties. harvested, trying to avoid wounding, Material and methods sorted and heaped on the field and Experimental design covered with fresh sweetpotato vines. The experimental design used was a Freshly harvested roots (uncured), 2×3×2 factorial design in a split plot together with roots from the two curing arrangement with treatment factors: treatments stated above were stored in Two cultivars (Apomuden and Nane), either sand box (Plate 2a) or under heap three curing options (Field-piled, storage (Plate 2b) in two successive dehaulming and uncured) and two farming seasons. household-level storage methods (Heap and Sand box).

Cultivars Two OFSP cultivars: Apomuden and Nane were planted in two successive farming seasons (August 2014 during the first season) and (July 2015 in the second season) at Bontanga in the Plate 1a: In-ground/dehaulming method Kumbungu district, Tamale, Ghana. All good agronomic practices such as weed and insect control were adhered until they were harvested at optimum 288 Shelf life extension and sensory properties

given three wounds on the first day using a potato peeler. In the in-ground curing soil surrounding selected roots was removed exposing the root so as to create the wounds, after which it was covered back with the soil and allowed to cure in-ground. On the other hand, in the field-piled curing, harvested Plate 1b: Field-piled curing method roots were randomly selected from the curing treatments for the wounds to be created. Wounded roots were placed back into their respective field-piles for the wound healing test. Wound healing test was carried out daily for seven days using Weiners’ phloroglucinol-HCl test as described elsewhere (van Oirschot et Plate 2a: Sand box storage (proposed al., 2001). Wounded sections were cut method) (approximately 2 cm × 5 cm and 1.7 mm deep) and stained with phloroglucinol (1% in 95% ethanol) for two minutes and transferred to concentrated HCl for 30 seconds before rinsed in water for 30 seconds. The wounds were stained with phloroglucinol for the presence or absence of lignin. A wound Plate 2b: Heap storage (farmers’ method) healing score of 0, 0.5 or 1 was given based on the level of lignin formed (no Wound healing lignification, patchy lignification and Twenty one (21) roots from each complete lignification respectively) as curing method mentioned above were shown (Plate 3). randomly selected and deliberately

0=No lignification 1= complete lignification 0.5= Patchy lignification Plate 3: Wound healing score of sweetpotato Shelf life extension and sensory properties 289

Dry matter determination season I; and 91consumers (female = Three roots each from the curing 14, male = 77) for season II. A five point treatment mentioned above was hedonic scale: 1= extremely dislike, 2= taken daily for dry matter content dislike, 3=neither like nor dislike, 4= determination. The dry matter content like and 5= like extremely was used to determination preceded the wound assess the sensory qualities of boiled healing test. Thus after wound sections roots. The sensory qualities evaluated were removed for the wound healing were: general appearance, finger- test, the roots were then sliced for feel firmness, sweetness and overall dry matter content determination as acceptability. The attribute sweetness described elsewhere (AOAC, 2005). was explained to panelist to mean About 10 g of sliced roots was weighed desired taste (palatability) as described and dried in Heratherm oven at 108°C by other researchers (Kapinga, for 16 hours. Percent dry matter content Jeremiah, Rwiza, & Rees, 2003). Each was determined by dividing dried panelist was presented with a plate sample weight by the fresh weight and containing all treatments for them to expressed as a percentage. assess and recorded on a sensory ballot sheet. Consumers rinsed their mouth Sensory analysis with water before and between samples Sound roots from each treatment were during the assessment. selected into labelled net bags. The roots were then washed under running Statistical analysis tap water and transferred into a cooking Data on the root quality parameters sauce pan. Water was then added until was analysed using two-way analysis it reached the level of the roots and of variance in Minitab.v16.2.4.4TM then boiled until it was soft as would (Minitab Inc., State College, PA, be eaten (15-20 minutes). USA). The Tukey’s studentised range The peels of the cooked roots were test was used to compare differences removed using a knife and sliced to between means when the ANOVA thumb sizes for the consumer preference result was significant (p< 0.05). test. Disposable plates were coded with Statistical analysis for the sensory three figured-codes and then samples data was performed using Microsoft® were served for scoring by the panelist. Excel 2010/XLSTAT©-Pro (Version The boiled roots were evaluated by 121 2016.02, Addinsoft, Inc., Brooklyn, consumers (female = 76, male = 45) for NY, USA). The Mann-Whitney test 290 Shelf life extension and sensory properties

was used to analyse treatments with healing score compared with Nane in only two levels (cultivar and storage the first faming season. However, type). Kruskal-Wallis non-parametric no statistical differences (p = 0.120) test procedure was employed to analyse were observed among cultivars in the the curing treatment. Multiple pairwise second year. Sweetpotato cultivars comparisons was done using the Steel- vary considerably in their ability to Dwass-Critchlow-Fligner procedure/ heal wounds (van Oirschot et al., Two-tailed test when p < 0.05. 2001). The ability of a cultivar to form lignin after wounding, is an indicator Result and Discussion of good storability because formation A measure of the wound healing of lignin reduces water loss and entry ability of Apomuden and Nane using of pathogenic microorganisms (van lignification score was conducted over Oirschot et al., 2001) that predisposes a 7-day period in field-piled curing. roots to spoilage. Apomuden tend to The results are presented in Figure 1. have superior wound healing ability Apomuden recorded a significantly and this suggest that it may perform higher (0.81 vs. 0.60; p = 0.001) wound better during storage.

Farming season I Farming season II Figure 1: Cultivars response to wound healing during curing for the two farming seasons Bar values (least square means ± SEM, resulted in a significantly higher (0.86) n = 3). Least square means with the same wounding healing score relative to the letter are not significantly different (p > in-ground curing (0.75) (p = 0.001) as 0.05) shown in Figure 2. This implies that in The field-piled curing method field-piled curing, roots are better able Shelf life extension and sensory properties 291

to heal their wounds compared with likely to occur faster in the former than dehaulming, as wound desiccation is the latter.

Figure 2: Wound healing as affected by curing method during the second farming season Bar values (least square means ± SEM, field-piled. The interaction between n = 3). Least square means with the same cultivar and curing time, though not letters are not significantly different (p significant, followed a similar trend in > 0.05). both years (Figure 3). Wound healing scores increased with increased curing time in both seasons (Figure 2). The current data supports earlier findings that lignified cell score, directly relates to curing time (Walter Jr., Hammett, & Giesbrech, 1989). The findings further suggest

Farming season I Farming season II that cultivars might have established Figure 1: Cultivars response to wound healing during curing for the two farming their wound periderm after the 4th day seasons of field-piled curing. Artschwager and Starrett (1931) reported that the establishment of a wound periderm is the final stage of wound healing. Therefore, the curing time could be at least 4 days when cured under 292 Shelf life extension and sensory properties

Farming Season 1

Farming Season 1 Farming Season 1I Figure 4: An interaction plot between cultivar and day on the wound healing score for farming season I and II Values are least square means ± SEM, n = 3. The dry matter content of sweetpotato is an important root characteristic that determines the Farming Season 1I suitability of a variety (Rukundo, Figure 3: Daily average wound healing Shimelis, Laing, & Gahakwa, 2013). scores during curing for farming season The dry matter of Nane was significantly I and II high (27% vs.19%, p < 0.001) compared Values are least square means ± SEM, n with Apomuden (Figure 4). = 3. Least square means with the same letter are not significantly different (p > 0.05). Shelf life extension and sensory properties 293

Figure 5: Dry matter of sweetpotato cultivars during the second farming season Bar values (least square means ± SEM, n = 3). Least square means with the same letter are not significantly different (p > 0.05). This is an important root quality when officially released. trait for OFSP cultivars and does not Least square means with the same agree with previous reports that OFSP letters are not significantly different (p cultivars are generally low in dry > 0.05) matter content (20.9%-24%) (Vimala, Nambisan, & Hariprakash, 2013). Rukundo and co-workers (2013) opined that cultivars with high dry matter (>25%) are desirable for farmers adoption as a new variety. The dry matter content of Nane was fairly stable compared with Apomuden that varied greatly throughout the curing period (Figure 5). Therefore, the high dry matter content of Nane coupled with its stability during curing are desirable trait for OFSP cultivars and could complement other existing OFSP varieties in Ghana 294 Shelf life extension and sensory properties

Figure 6: Influence of curing method on the dry matter content of sweetpotato over a 7-day curing period in farming season II Values are least square means ± SEM, n = 3. Least square means with the same letters are not significantly different (p > 0.05). Curing and storage greatly influence the dry matter content of sweetpotato roots (Picha, 1986). The data presented in Figure 7 shows that field-piled curing had a significantly high (24%, p = 0.020) dry matter content relative to in- ground curing (22%). The differences in the dry matter content between the two curing methods could be attributed to high water loss resulting in increased dry matter content (Ravi et al., 1996) for field-piled cured roots compared with in-ground curing. Shelf life extension and sensory properties 295

Figure 7: Dry matter as influenced by curing method Bar values (least square means ± SEM, n = 3). Least square means with the same letters are not significantly different (p > 0.05). No significant difference was observed There was no significant difference between the curing treatments in terms between curing methods with respect of weight loss during the first season as to weevil damage in the first year. shown in Figure 8. However, during the Meanwhile no weevil damage was second season significant differences recorded in the second season. Cylas was observed between treatments. spp was the observed weevil in storage Dehaulmed roots in storage consistently during the first season. This agrees with recorded low weight loss, 16% and previous studies that in northern Ghana, 7.4%, respectively in the first and the sweetpotato weevil, Cylas spp is the second seasons compared with field- most abundant and economic important piled (17% and 12%, respectively) and insect among other insects (Tanzubil, uncured (19% and 9.3%, respectively). 2015). Sprouts were significantly high Percent rot followed a similar trend in in dehaulmed treatment compared to both season as rots were significantly filed-piled and uncured. lower in the dehaulmed treatment relative to field-piled and uncured

Farming season I Farming season II 296 Shelf life extension and sensory properties

Farming season I

Farming season II Figure 8: The influence of curing method on the physical quality of roots for season one and two Bar values (least square means ± SEM, n = 3). Least square means with the same letter are not significantly different (p > 0.05). Shelf life extension and sensory properties 297

Farming season I

Farming season II Figure 9: Physical root qualities of cultivars during storage for farming season I and II. Bar values (least square means ± SEM, n = 3). Least square means with the same letter are not significantly different (p > 0.05). 298 Shelf life extension and sensory properties

Figure 9 shows sweetpotato root quality factors: weight loss, rot, weevil damage and sprouts during storage. The percent weight loss recorded in Apomuden was almost twice that of Nane in both growing seasons, and the differences could be attributed to the high moisture content of Apomuden in Farming season I weight loss among cultivars have been acknowledged and reported (Mehra & Dayal, 1991). Percent rots followed a similar trend with Apomuden recording higher rots in both growing seasons. This is in spite of the slightly better wound healing properties of Apomuden. . The susceptibility of Apomuden could be attributed to its thin skin making it prone to pathogenic microbial attack. Thus for these two genotypes, Farming season II lignification is not a good indicator of Figure 10: Physical root qualities of storability. Lignification, a measure sweetpotato as influenced by storage type for farming season I and II of wound healing has been suggested Bar values (least square means ± SEM, n as indicator of better storability (van = 3). Least square means with the same Oirschot et al., 2001). Previous studies letter are not significantly different (p > showed that Beauregard had a superior 0.05). wound healing characteristics but has been considered skinning susceptible The sand box storage showed lower in U.S production regions (Rees, van weight loss, about 1.3 times lower Oirschot, & Aked, 2008). Nane on than the moistened straw heap method the other hand showed good storage for both growing season (Figure qualities and could potentially serve 10). The current findings supports as a household-level dietary source of that of Chattopadhyay et al. (2006) vitamin A. who reported that physiological loss of weight of sweetpotato cultivars were less in the sand medium (15%) Shelf life extension and sensory properties 299

compared to saw dust (17%) after 75 household consumption for food and days of storage and 25% in exposed nutrition security in northern Ghana. storage (control) when stored for 50 During the second season no days. This is an indication that the sand weevil damage was observed in the medium provided enough protection to two storage method. This also shows roots thereby reducing respiration and that careful selection of roots is crucial transpiration that largely contribute to storage. Sweetpotato sprouted almost physiological weight loss in sweetpotato twice as in the sand box compared to (Jenkins, 1982; Picha, 1986). Although the heap method contrary to the findings no significant difference was observed of Chattopadhyay et al. (2006) that between the two storage types in terms reported no sprouts in the sand medium of rots during the first season, the sand storage. The observed sprouts in the box recorded low rots (17%) relative sand box could be an indication of good to the heap storage (19%). However, quality roots as reported elsewhere that in the second farming season the heap good roots sprout often (van Oirschot method had a significantly higher rot et al., 2007). Nonetheless sprouts are (12%), almost twice that of the sand box often broken off as a control measure. method (7.7%). The sprinkling of water The second year recorded no sprouts every other day in the heap storage could over the 8-week storage in either sand have created conducive environment box or heap storage. for the growth of pathogenic microbes The sensory scores for all the resulting in increased root decay. The sensory attributes above 3 on the type of storage significantly influenced 5-point hedonic scale in both farming weevil damage during the first year. seasons an indication of good consumer The sand box recorded about 22 times preference (Muhimbula, Issa-Zacharia, low weevil damage compared with the & Kinabo, 2011) for both cultivars heap method (6%). The data on the low (Table 1). However, in the first season, incidence of weevil damage of the roots Apomuden had a significantly lower stored in the sand box method indicate score for sweetness (3.34 vs. 3.83, p that the sand medium served as a block < 0.0001) and overall acceptability restricting the movement of the weevils (3.48 vs. 3.76, p = 0.034) compared from one root to the other. The findings with Nane. The lower score of of this study therefore suggests that sweetness (sugariness) was in spite of sweetpotato, especially OFSP, can be higher fructose, glucose and sucrose stored in sand boxes up to 9 weeks for concentrations than Nane. It could be 300 Shelf life extension and sensory properties

deduced that the “sweetness” attribute sweetpotato root quality. The OFSP was rated by the panelist as palatability cultivars have often been rated instead of sugariness. The differences poorly regarding finger-feel firmness in cultivars’ overall acceptability could (Leksrisompong, Whitson, Truong, be attributed to taste (palatability) as it & Drake, 2012) probably due to their was among other factors being reported generally, low dry matter (20-24%) to be the main driving forces of overall contents (Tomlins, Owori, Bechoff, acceptability of sweetpotato cultivars Menya, & Westby, 2012; Vimala et al., (Kwach, Odhiambo, Dida, & Gichuki, 2013). However, Nane is relatively high 2010). in dry matter (27%) and it is reported In the second farming season, that, African consumers prefer high cultivars did not differ (p > 0.05) in dry matter cultivars (Baafi et al., 2015; all sensory attributes except for finger- Tomlins et al., 2004). Based on Walter feel firmness that Nane had a higher (1987) it was expected that Apomuden score (3.63 vs. 3.35, p = 0.003) than should have been the most preferred Apomuden. This could be attributed to cultivar, but it was not the case as this the high dry matter content, averagely, study shows. Thus, Nane, the cultivar 27% for Nane. According to Kapinga under evaluation for release in Ghana et al. (2003), firmness is an indicator could have high consumer acceptability. of high dry matter content, a preferred Shelf life extension and sensory properties 301 a a a a a b ab 0.001 0.224 0.224 229.59 288.99 Overall 255.57 3.63±1.15 3.75±1.13 3.63±1.15 3.75±1.13 Acceptability a a a a a a b 0.000 0.157 0.210 241.03 238.49 296.29 Sweetness 3.54±1.11 3.66±1.09 3.54±1.13 3.70±1.06 a a a b a a b 0.903 0.003 Farming Season II Farming 243.80 233.69 298.93 <0.0001 Firmness 3.51±1.12 3.49±1.13 3.35±1.11 3.63±1.12 Finger-feel Finger-feel =91; Male=14, Female=77) ( n =91; Male=14, - a a a b - a b b 0.000 0.539 0.094 233.69 278.98 266.10 3.53±1.07 3.63±1.16 3.58±1.12 3.66±1.18 e not sinifi Gen. Appearance a a a b a a a Sensory Attributes 0.261 0.397 0.000 317.07 304.49 288.62 Overall 3.69±1.01 3.60±1.10 3.44±1.15 3.76±0.98 Acceptability a a b b a a a 0.335 288.61 312.42 306.54 <0.0001 <0.0001 Sweetness 3.30±1.16 3.84±1.04 3.83±1.03 3.47±1.13 a a a a a a a 0.779 0.569 0.116 309.40 297.98 304.94 Farming Season I Farming Firmness 3.32±1.13 3.35±1.17 3.26±1.16 3.39±1.15 Finger-feel =121; Male=45, Female=76) ( n =121; Male=45, methods (heap vs. sand box) vs. sand (heap methods a a a a a b ab 0.004 0.491 0.149 271.48 329.58 307.97 3.49±1.26 3.45±1.21 3.39±1.13 3.40±1.14 Gen. Appearance Nane Heap type* Storage Storage P-Value P-Value P-Value Curing# Uncured Sand box Sand Cultivar* In-ground Field-piled Apomuden cantly different (P > 0.05) (P cantly different mean of ranksScale: 1= ex are Deviation); #Values (means ± Standard are *Values dislike, 2= 3=neither like nor 4= and 5= extremely tremely Means/mean ranks in the same category a column with letter ar Table 1: Sensory scores of boiled OFSP roots after being cured/uncured and stored using stored and cured/uncured being after roots OFSP boiled of scores Sensory 1: Table two household-level storage 302 Shelf life extension and sensory properties

In the two successive farming had no significant effect on all the seasons, in-ground curing consistently sensory qualities of sweetpotato roots. had higher consumer ranks for general Mpagalile et al. (2007) also reported appearance compared with field-piled that improved open pit, improved and uncured. This may imply that root house pit and raised woven structure that were cured in-ground and stored had no significant influence on the in sand box or under heap methods acceptability of sweetpotato except for improves the cooking properties of the the traditional pit storage. roots. Considering that it is easier to do, Gender is a major factor dehaulming should be recommended to that determines the success and all sweetpotato farmers. sustainability of any intervention The curing method could have including OFSP dissemination. Both promoted the synthesis of α – and males and females similarly ranked β-amylase enzymes that hydrolyses sweetness and overall acceptability with starch during cooking leading to the exception of general appearance the formation of monosaccharides, and finger-feel firmness for farming precursors for vital flavour components season I. This is an indication that both as reported elsewhere (Wang, Horvat, cultivars could be equally accepted by White, & Kays, 1998). Both curing both male and female. Importantly, methods generally resulted in roots the preference of the OFSP cultivars with better sensory quality than uncured by men, who are usually household treatment because the increased enzyme heads, implies that these β-carotene- activity and sugars concentration make rich food crops are likely to be prepared the boiled-cured roots become sweet and consumed at the household-level. and moist (Walter, 1987). However, the finding in this study Storage type showed no contradicts earlier studies by Tomlins significant difference (p > 0.05) in et al. (2004) and (2007) who reported all sensory attributes in both farming that female consumers preferred some seasons. This is an indication that sweetpotato cultivars more than their cultivars stored either in sand box or male consumers. The high ranking under heap for a maximum of 8-9 weeks of general appearance and finger-feel will be equally accepted by consumers. firmness by the female consumers The findings agree with van Oirschot suggest that Ghanaian children would and co-workers (2003) who reported prefer the OFSP cultivars as have been that apart from fibrousness, storage reported elsewhere (Skinner, Carruth, Shelf life extension and sensory properties 303

Bounds, & Ziegler, 2002), since foods days as wound healing is completed not preferred by mothers are not for cultivars by the 4th day. The sand normally offered to children. Therefore, box storage improved the physical in Ghana, and particularly in the rural and culinary properties of the OFSP communities where VAD prevalence is roots up to 2 months and should be usually high, OFSP has the potential to recommended to farmers in Ghana and be a dietary source of vitamin A for at possibly in the sub region. least two months in the year. Acknowledgements Conclusion Funding received from International Sweetpotato root are able to Potato Center under the project SASHA cure their wounds better in field-piled II: Sweetpotato Action for Security and curing than in-ground curing. Field- Health in Africa is heartily valued and piled curing should be done for 4 acknowledged. 304 Shelf life extension and sensory properties

REFERENCE

Amand, P. C. S., & Randle, W. M. (1991). Ethylene production as a possible indicator of wound healing in roots of several sweet potato cultivars. Euphytica, 53, 97-102. AOAC. (2005). Cereal Foods (AOAC International. Official Method AOAC 925.10 for Moisture in Flour). Official methods of analysis of the association of official analytical chemists, 17th ed. Gaithersburg, Maryland. Artschwager, E. F., & Starrett, R. C. (1931). Suberization and wound-periderm formation in sweet potato and gladiolus as affected by temperature and relative humidity. Journal of Agricultural Research, 43, 353-364. Baafi, E., Manu-Aduening, J., Carey, E. E., Ofori, K., Blay, E. T., & Gracen, V. E. (2015). Constraints and Breeding Priorities for Increased Sweetpotato Utilization in Ghana. Sustainable Agriculture Research, 4(4), 1. Chattopadhyay, A., Chakraborty, I., Kumar, P. R., Nanda, M. K., & Sen, H. (2006). Uncontrolled storage behaviour of sweet potato (Ipomoea batatas L. Lam). Journal of Food Science and Technology-Mysore, 43(1), 41-45. Edmunds, B. A., Boyette, M. D., Clark, C. A., Ferrin, D. M., Smith, T. P., & Holmes, G. J. (2008). Postharvest handling of sweetpotatoes. North Carolina State University Cooperative Extension Service. Jenkins, P. D. (1982). Losses in sweet potatoes (Ipomoea batatas) stored under traditional conditions in Bangladesh Journal of Tropical Science, 24(1), 17-28. Kapinga, R., Anderson, A., Crissman, C., Zhang, D., Lemaga, B., & Opio, F. (2005). Vitamin A partnership for Africa: A food based approach to combat vitamin A deficiency in sub-Saharan Africa through increased utilization of orangefleshed sweetpotato. Chron Horticult, 45, 12-14. Kapinga, R., Jeremiah, S., Rwiza, E., & Rees, D. (2003). Farmer criteria for selection of sweet potato varieties. Sweet potato postharvest assessment: experiences from East Africa. Chapman: Sweet potato postharvest assessment: Experiences from East Africa, 9-21. Kwach, J. K., Odhiambo, G., Dida, M., & Gichuki, S. (2010). Participatory consumer evaluation of twelve sweetpotato varieties in Kenya. African Journal of Biotechnology, 9(11), 1600-1609. La Bonte, D. R., & Wright, M. E. (1993). Image analysis quantifies reduction in sweetpotato skinning injury by preharvest canopy removal. Hortscience, 28(12), Shelf life extension and sensory properties 305

1201. Leksrisompong, P., Whitson, M., Truong, V.-D., & Drake, M. (2012). Sensory attributes and consumer acceptance of sweet potato cultivars with varying flesh colors. Journal of Sensory Studies, 27(1), 59-69. Low, J., Walker, T., & Hijmans, R. (2001). The potential impact of orange-fleshed sweetpotatoes on vitamin A intake in Sub-Saharan Africa. Mehra, S. K., & Dayal, T. R. (1991). Comparing low cost sweetpotato storage in India. In T. R. Dayal, G. J. Scott, G. T. Kurup & C. Balagopalan (Eds.), Sweetpotato in South Asia: postharvest handling, processing, storage and use (pp. 125-131). India: CIP and CTCRI. Mpagalile, J. J., Silayo, V. C. K., Laswai, H. S., & Ballegu, W. R. (2007). Effect of different storage methods on the shelf-life of fresh sweetpotatoes in Gairo, Tanzania. In R. E. Kapinga, R. Kingamkono, M. Msabaha, J. Ndunguru, B. Lemaga & G. Tusiime (Eds.), Tropical Root and Tuber Crops: Opportunities for Poverty Alleviation and Sustainable Livelihoods in Developing Countries:Proceedings of the Thirteenth Triennial Symposium of the International Society for Tropical Root Crops (ISTRC) (pp. 500-505). Arusha, Tanzania: International Society for Tropical Root Crops. Muhimbula, H. S., Issa-Zacharia, A., & Kinabo, J. (2011). Formulation and sensory evaluation of complementary foods from local, cheap and readily available cereals and legumes in Iringa, Tanzania. African Journal of Food Science, 5(1), 26-31. Namanda, S., Amour, R., & Gibson, R. (2013). The Triple S Method of Producing Sweet Potato Planting Material for Areas in Africa with Long Dry Seasons. Journal of Crop Improvement, 27(1), 67-84. Ndunguru, G. T., Tomlins, K. I., Rwiza, E., & Westby, A. (2000). Methods for reducing postharvest handling losses of sweetpotato (Ipomoea batatas (L) Lam). 1-19. Picha, H. D. (1986). Weight loss in sweetpotatoes during curing and storage: Contribution of transpiration and respiration. American Society for Horticultural Science, 111(6), 889-892. Ravi, V., Aked, J., & Balagopalan, C. (1996). Review on tropical root and tuber crops I. Storage methods and quality changes. Critical Reviews in Food Science and Nutrition, 36(7), 661-709. doi: 10.1080/10408399609527744 Ray, R. C., & Ravi, V. (2005). Postharvest spoilage of sweetpotato in tropics and control measures, critical reviews in food science and nutrition. 45(7-8), 623-644. doi: 10.1080/10408390500455516 Rees, D., van Oirschot, Q. E. A., & Aked, J. (2008). The role of carbohydrates in wound- healing of sweetpotato roots at low humidity. Elsevier, 50, 79-86. doi: 10.1016/j. 306 Shelf life extension and sensory properties

postharvbio.2008.03.019 Rukundo, P., Shimelis, H., Laing, M., & Gahakwa, D. (2013). Storage root formation, dry matter synthesis, accumulation and genetics in sweetpotato. Australian Journal of Crop Science, 7(13), 2054-2061. Skinner, J. D., Carruth, B. R., Bounds, W., & Ziegler, P. J. (2002). Children’s food preferences: a longitudinal analysis. Journal of the American Dietetic Association, 102(11), 1638-1647. Sowley, E. N. K., & Oduro, K. A. (2002). Effectiveness of curing in controlling fungal- induced storage rot in sweetpotato in Ghana. Journal of Tropical Science, 42(1), 6-10. Tanzubil, B. P. (2015). Insect pests of sweet potato in the Sudan savanna zone of Ghana Journal of Entomology and Zoology Studies 3(2), 124-126. Tomlins, K., Ndunguru, G., Stambul, K., Joshua, N., Ngendello, T., Rwiza, E., Amour, R., Ramadhani, B., Kapande, A., & Westby, A. (2007). Sensory evaluation and consumer acceptability of pale‐fleshed and orange‐fleshed sweetpotato by school children and mothers with preschool children. Journal of the Science of Food and Agriculture, 87(13), 2436-2446. Tomlins, K., Ngendello, T., Rwiza, E., Nyango, A., Kapinga, R., Rees, D., Amour, R., & Jolliffe, F. (2004). The use of sensory evaluation and consumer preference for the selection of sweetpotato cultivars in East Africa. Journal of the Science of Food and Agriculture 84, 791–799 doi: 10.1002/jsfa.1712 Tomlins, K., Owori, C., Bechoff, A., Menya, G., & Westby, A. (2012). Relationship among the carotenoid content, dry matter content and sensory attributes of sweet potato. Food Chemistry, 31(1), 14-21. doi: http://dx.doi.org/10.1016/j. foodchem.2011.07.072 Tomlins, K., Rees, D., Coote, C., Bechoff, A., Okwadi, J., Massingue, J., Ray, R., & Westby, A. (2010). Sweet potato utilization, storage, small-scale processing and marketing in Africa. In R. C. Ray & K. I. Tomlins (Eds.), Sweet Potato: Post Harvest Aspects in Food, Feed and Industry (pp. 271-293). New York: Nova Science Publishers, Inc. Tumwegamire, S., Mwanga, R. O. M., Andrade, M., Low, J. W., Ssemakula, G. N., Laurie, S., Chipungu, P. F., Ndirigue, J., Agili, S., Karanja, L., Chiona, M., Njoku, J. C., Mtunda, K., Ricardo, J., Adofo, K., Carey, E., & Gruneberg, W. J. (2014). Orange-fleshed sweetpotato for Africa. Catalogue 2014 (Second Edition) (pp. 74). Lima, Peru: International Potato Center (CIP). van Oirschot, Q., Ngendello, T., Rwiza, E., Amour, R., Tomlins, K., Rees, D., & Westby, A. (2007). The potential for storage of fresh sweetpotato under tropical conditions: Evaluation of physiological changes and quality aspects. In R. E. Shelf life extension and sensory properties 307

Kapinga, R. Kingamkono, M. Msabaha, J. Ndunguru, B. Lemaga & G. Tusiime (Eds.), Tropical Root and Tuber Crops: Opportunities for Poverty Alleviation and Sustainable Livelihoods in Developing Countries:Proceedings of the Thirteenth Triennial Symposium of the International Society for Tropical Root Crops (ISTRC) (Vol. 423-434). Arusha, Tanzania: International Society for Tropical Root Crops van Oirschot, Q. E. A., Rees, D., & Aked, J. (2003). Sensory characteristics of five sweet potato cultivars and their changes during storage under tropical conditions. Food Quality and Preference, 14(8), 678-680. doi: http://dx.doi.org/10.1016/S0950- 3293(02)00209-4 van Oirschot, Q. E. A., Rees, D., Lucas, C., Maina, D., Mcharo, T., & Bohac, J. (2001). Sweetpotato: germplasm evaluation for wound healing efficiency. Acta Horticulturae, 584(31–40). Vimala, B., Nambisan, B., & Hariprakash, B. (2013). Variability of Carotenoids and Dry Matter Content in Orange-fleshed Sweet Potato (Ipomoea batatas (L.) Lam.) During Storage. Journal of Root Crops, 37(2), 182. Walter Jr., W. M., Hammett, L. K., & Giesbrech, F. G. (1989). Wound healing and weight loss of sweet potato harvested at several soil temperatures Journal of the American Society for Horticultural Science, 114(1), 94-100. Walter, W. M., Jr. (1987). Effect of curing on senory properties and carbohydrates composition of baked sweet potatoes. Journal of Food Science, 52(4), 1030-1032. Walter, W. M., Jr., Hammett, L. K., & Giesbrech, F. G. (1989). Wound healing and weight loss of sweet potato harvested at several soil temperatures Journal of the American Society for Horticultural Science, 114(1), 94-100. Wang, Y., Horvat, R. J., White, R. A., & Kays, S. J. (1998). Influence of postharvest curing treatment on the synthesis of the volatile flavor component in sweetpotato Paper presented at the Postharvest 96, Leuven, Belgium. Woolfe, J. A. (1992). Sweet potato: An untapped food resource: Cambridge University Press. Cambridge, UK. World Health Organization. (2009). Global prevalence of vitamin A deficiency in populations at risk 1995–2005. WHO global database on Vitamin A deficiency. Geneva, World Health Organization. Geneva, Switzerland: WHO Press. 308

Protein and Beta-carotene in Maize-Sweet Potato Fermented Composite Flours

Enoch T. Quayson1, Martin Bosompem 2, Henry D. Acquah 2 and Anna Kuevi 3 1. Department. of Biochemistry, School of Biol. Sciences, College of Agriculture and Natural Sciences, University of Cape Coast, Ghana. 2. Department of Agriculture Economics and Extension, School of Agriculture, College of Agriculture and Natural Sciences, University of Cape Coast, Ghana. 3. Department of Dietetics, School of Allied Health Sciences, University of Ghana, Ghana.

ABSTRACT protein and vitamin A. Maize-sweet Maize (Zea mays) is a cereal that has potato flours were made with ratio of a wide range of food applications 80:20, 70:30, and 60:40 in incremental especially for its high carbohydrate order of sweet potato fermented for 48 content. Sweet potato (Ipomea batatas) hours. Beta-carotene and crude protein is one of the underutilized root/tuber contents of the flour after drying were crops that is rich in beta carotene determined by standard methods. and has low glycemic index and can The result shows that the β-carotene be used as food for pre-schoolers, (mg/100g) in maize-sweet potato flour diabetics, and as complementary food of ratio 60:40 (mean-10.0304 ± 0.001) for infants. Moreover, it has no rigorous was significantly higher than that planting practices, matures within three of 70:30 (mean: 4.6419 ± .003) and months after cultivation, can be grown 80:20, (1.7848 ± 0.005) at 0.01 alpha throughout the year, and can be cultivated level. Moreover, the percentage crude in both the forest and savannah regions protein content in the maize-sweet in most African countries including potato flour of ratio 60:40 (mean: 8.21 Ghana. The objective was to find out ± 0.22) was significantly different from the combination of sweet potato and that of 80:20, (9.58 ± 0.33) but not maize that gives the best composite with that of 70:30 (mean: 7.80 ± 0.33) flour in terms of nutrients especially at 0.01 alpha level. The maize-sweet Protein and Beta-carotene in Maize-Sweet Potato 309

potato flour of ratio 60:40 emerged vitamin A deficiency. A complementary with highest amount of β-carotene food developed from maize and sweet reasonable amount of protein with a potato seems to have that potential. potential for use in addressing vitamin Fermented maize dough is A needs among resource poor. already being used in many infant foods even though it has poor nutritional Introduction value when cooked and eaten without Sweet potato maize composite flours some ingredients such as milk. It is however readily available and Protein energy malnutrition has long affordable to many consumers. Sweet been a problem of infants in many potato is considered as an underutilized developing countries (Pinstrup- root crop that has low utilization and Andersen et al., 1993; Millward et al., a limited food base. It is cultivated 2004) especially after the weaning stage. throughout the year in the tropics and Although progress has been made in the has no rigorous cultural practices. It last couple of decades to address the has rich nutritional qualities such as problem, it still exists most especially pro-vitamin A carotenoids. It has been in resource poor communities. There found to increase the serum retinol of have been efforts to optimize existing children marginally deficient in vitamin traditional complementary foods and A. A study by Hagenimana et al. (1998) to develop new ones that have high found that increased consumption protein. However, many still resort of either the fresh or processed form to the traditional porridge which of sweet potato can contribute to is a cooked gruel from fermented alleviating vitamin A deficiency. maize dough as complementary food. Ferguson and Darmon (2007) reported There are also incidences of vitamin that vitamin A-rich traditional foods A deficiency among infants five were successful in improving vitamin A years and under in many Ghanaian status of infants. Low et al. (2007) found communities (GHS, 1997). There is it has a synergistic effect in augmenting the need for development of alternative the vitamin A status of infants under complementary foods that use local five who were receiving vitamin A food materials that are inexpensive and supplements. Moreover, fermentation affordable and that has the potential has been found to improve nutrient of helping to address the problems levels and reduce anti-nutritional of protein energy malnutrition and factors in food commodities (Sahana 310 Protein and Beta-carotene in Maize-Sweet Potato

and Fauzia, 2003). Earlier preliminary important nutritional component in work by Tandoh et al. (2013) showed foods, as a major precursor of vitamin maize-sweet potato fermented dough A, and provides pleasant yellow-orange flour to have substantial improvement colours to foods (Simon, 1997). Dietary of protein in comparison to fermented vitamin A deficiency causes debilitating maize dough. The work reported here health problems such as xerophthalmia, investigated the β-carotene and crude corneal lesions, keratomalace, and protein content of flours from maize- in many instances, death. The World sweet potato fermented doughs with Health Organization (WHO, 1995) had different combination of maize and reported these problems as affecting sweet potato. It is part of a larger young children in Africa. Sweet potato study that is investigating the effect is reported to have remarkable pro- of maize-sweet potato composite vitamin A quality (Woolfe, 1992). flour on the nutritional status of lower Sweet potatoes (Ipomoea batatas L. primary school pupils in resource poor Lam) are an economical and healthy communities in parts of food crop containing high β-carotene, of Ghana. substantial amounts of ascorbic acid and minerals (Woolfe, 1992). Nutritional Importance Sweet potato is a herbaceous of Sweet Potato perennial and the edible portion is the Recent studies have associated tuberous root though the young leaves the consumption of foods rich in and shoots are eaten as well (Woolfe, carotenoids with decreased incidence 1992). The crop is now cultivated of cancers in humans (Gerster, throughout the tropics and subtropics; 1993). That and the possible role of it is ranked seventh among the most carotenoids in immunity, fertility, and important crops worldwide (Scott, early prophylaxis of cardiovascular 1992; Zhang and Corke, 2001). The diseases in livestock, have generated ranking differs from country to country; interest in these compounds (Pfander, in China it is ranked fourth as a food 1992). Carotenoids represent the crop after rice, wheat and maize (Li most widespread group of naturally et al., 1992) while in Sierra Leone, it occurring pigments in nature. They is ranked third after rice and cassava are primarily of plant origin and (IAR, 2009). β-carotene, with few exceptions, Since the 1990s, the main strategy predominates. β-carotene serves as an for combating vitamin A deficiency in Protein and Beta-carotene in Maize-Sweet Potato 311

Africa has been to distribute massive- sustainable food production systems dose capsules using donations from in the tropics (Amoah et al., 2011). In UNICEF (Kennedy and Oniango, parts of West, Central, and East Africa, 1993). Mothers who do not identify sweet potato is an important source of adverse physical symptoms in their calories and is consumed by all age children often neglect returning for groups (Hagenimana et al., 1998). additional doses. The same benefit Children in the group most at risk of can be achieved if children consume vitamin A deficiency particularly like sufficient quantities of β-carotene and sweet potato (Low et al., 1997). Widely vitamin A-rich foods. This is one of consumed cultivars, however, have the most reliable, readily available, white or pale yellow flesh and contain and most sustainable approaches to very little β-carotene (Ameny and controlling vitamin A deficiency in Wilson, 1997). Consumption of orange- many rural areas of Africa where fleshed sweet potato roots and sweet chronic deficiencies as still common potato-based processed foods could (Roeles et al., 1958). Despite these provide sustainable, cost-effective and potential benefits that can be derived much needed vitamin A (Hagenimana from consumption of sweet potato and et al., 1998). the increased interest in its cultivation Fresh sweet potato roots are bulky in many parts of Africa and Asia, there and highly perishable. Its perishable are some post-harvest problems such as nature arises mainly because of the sprouting and spoilage that have to be thin delicate skin which easily gets overcome. damaged during harvesting and post harvest handling. As a result, the roots Storage Problems of are generally not harvested and stored Sweet Potato for extended time. The practice by most Sweet potato has been receiving farmers is to keep the mature sweet increasing attention in part because it potato roots in the field until they are grows on soils with limited fertility, needed for consumption or sale before is relatively drought tolerant, provides they are harvested, a practice christened good ground cover, and is often piecemeal harvesting (Rose, 1970; cultivated without fertilizer and Onueme, 1982; Smit, 1997). In semi- pesticide (Ewell, 1990). Those qualities arid regions, with long dry season, in- are attractive to agriculturalists and ground storage is practiced; however, it ecologists interested in developing is limited by attacks from sweet potato 312 Protein and Beta-carotene in Maize-Sweet Potato

weevils (Amoah et al., 2011). for the storage of two sweet potato In Ghana and other parts of varieties. Amoah et al. (2011) found that tropical developing countries, sweet the two storage structures used in the potato tuberous roots have storage study improved sweet potato storage by duration of only up to three weeks reducing general deterioration. One of (Rees et al., 2003; Teye, 2014). Storage the two structures – the Purposed Built of sweet potato tubers is usually in Evaporative Cooling Barn (PBECB) – pits using ash or in sacks. However, however had an edge over the other as pit storage has been found to be it was slightly better in reducing weight effective for at least four months and loss, weevil damage, shrinkage, decay is constrained by sweet potato weevil and more wholesome roots at the end damage, rotting and rodents (Moyo et of the storage period. The advantage in al., 2004). In addition, the use of ash the use of the second storage structure – in sweet potato storage has been found Modified Pit Storage Structure (MPSS) to produce unattractive and low market – was the slightly lower sprouting index value tubers due to shrinkage (Mbeza et compared to the PBECB (Amoah al., 1997). However, under controlled et al., 2011). Specifically, the roots atmosphere (Temperature range of 13- stored in the PBECB showed 66% 15˚C and RH of 90%) the roots can be wholesomeness, 53% weevil damage, stored up to a year (Woolfe, 1992; Rees 3.8% shrinkage, 30% weight loss, 58% et al., 2003). sprouting and 52% decay compared Currently, the cultivation of sweet with 60% wholesomeness, 53% weevil potato is being encouraged in West damage, 4.1% shrinkage, 38% weight Africa and East Africa states where loss, 74% sprouting and 60% decay of sweet potato is a staple. However, roots stored in the MPSS (Amoah et al., during the glut season, farmers find 2011). it difficult to store because they lack Indeed, Amoah et al. (2011) appropriate storage structures which report that after 12 weeks of storage of are able to reduce weevil damage, two cultivars of sweet potato (TIS 2 and and curb deterioration in store.Various Ukerewe), the TIS 2 stored better than storage methods are being investigated Ukerewe in both storage structures. This to access their potential in reducing was evident in its resistance to weevil postharvest spoilage of the crop. For damage, decay, shrinkage, decreased example, Amoah et al. (2011) evaluated weight loss and had more wholesome the potential of two storage structures roots in storage. It is possible to store Protein and Beta-carotene in Maize-Sweet Potato 313

TIS 2 sweet potato roots in both using gamma radiation to extend the storage structures for 10 weeks at 78- shelf-life of the sweet potato roots. 81% wholesomeness. For example, in This was because the major the PBECB storage structure, TIS 2 problems associated with the storage sweet potato stored for 3 months had of fresh tubers are sprouting and 76% wholesomeness, 12% weight loss, spoilage as highlighted in the preceding 29% decay and 3.4% shrinkage. The paragraphs. Sprouting of tubers leads results reported by Amoah et al. (2011) to the depletion of dry matter contents seem to suggest that storage structure of the commodities. Sprouting, which and conditions of each variety of sweet is undesirable during storage, is potato has to be investigated so as to promoted in tropical conditions. As a identify these for storage of the tuberous way to solve the sprouting problem, root for a period of 12 weeks with some several chemical treatments have been tolerable losses as evident in the reported utilised in stored sweet potatoes and work. It goes without saying, that such yams including naphthalene-acetic an exercise will be labour intensive acid and sodium hypochlorite solution and time consuming and will require (Paton and Scriven, 1989; Lewthwaite high skilled manpower. It is therefore and Triggs, 1995). Effective treatments important that other methods that have have also included pre-harvest spraying the potential to maintaining quality with maleic hydrazide, or treating the and quantity of sweet potato towards harvested tubers with the methyl ester improved processing technology and of naphthalene-acetic acid (MENA) in value added products are sought. acetone. Irradiation treatment is a viable Commercial utilization of sweet alternative to chemical fumigation for potato for industrial raw materials like sweet potato growers (Ocloo et al., flour and starch is nonexistent although 2011). it has the potential of adding value to Gamma irradiation has long the produce and helping create new been used to protect foods from insect domestic and export market niches for infestation and microbial contamination new products. However, increase in during storage. The effects of gamma utility would also depend on thorough irradiation on chemical composition understanding of the effect of processing of food products have received wide on their properties and functionality. It attention because of the concern about is with this in mind that Ocloo et al. food safety (Bao et al., 2005). The (2011) investigated the possibility of optimum irradiation dose for treating 314 Protein and Beta-carotene in Maize-Sweet Potato

sweet potatoes against insects and from each other. microbial contamination without In respect of pasting characteristics affecting quality may lie between 100 of the extracted starch, it was found and 500 Gy (Lu et al., l986). A dose that beginning of gelatinization of 600 Gy did not reduce the overall temperature of the samples increased quality or taste of purple-fleshed and with increase in gamma radiation dose yellow-fleshed sweet potatoes (Wall, (i.e. from 75.5-79.6°C. Maximum or 2004). Hallman (2001) also found that peak viscosity decreased from 1008.2 orange-fleshed roots treated with a 300 - 937.0 BU as the irradiation dose Gy dose did not differ from control increased. Generally, setback and roots in colour or organoleptic ratings. breakdown viscosities significantly The main objective of the study decreased with increasing irradiation by Ocloo et al. (2011) was to evaluate dose. The swelling power of starches the functional and physicochemical from irradiated sweet potato tubers characteristics of starch produced decreased with increased irradiation from gamma-irradiated sweet potato dose. However, the decrease in swelling tuberous roots for control of insects power was not statistically significant and sprouting. It involved exposure (p>0.05). The solubility of starches were of cleaned, sorted and packed sweet significantly (p<0.05) increased with potato tubers to four (0 kGy, 0.2 kGy, increase in irradiation dose. Gamma 0.3 kGy and 0.4 kGy) levels of gamma irradiation of sweet potato tubers to radiation doses. Starch was extracted control insects and sprouting influences from the irradiated tuberous roots and functionality of their resultant starches. evaluated for moisture, pH and pasting The result obtained therefore could be profile. Other characteristics of the useful in selecting appropriate dose extracted starch that were determined treatment of sweet potato tubers for a included swelling power, solubility, particular industrial application of the water absorption capacity and bulk resultant starches (Ocloo et al., 2011). density. The moisture contents of the While the efforts made in extending starch produced from the irradiated the shelf-life through prevention of sweet potatoes were between 10.02 and weevil infestation and reduction of 11.88 %. The pH of the starch produced sprouting are commendable, they do from the irradiated sweet potato ranged not conclusively solve the problem from 6.26 – 7.07 with the pH values of post-harvest spoilage. In addition, being significantly (p < 0.05) different the cost of the process, for example, Protein and Beta-carotene in Maize-Sweet Potato 315

irradiation could be very expensive green vegetables. Again, methods and the product obtained after the of processing for consumption have treatment could possibly be used in included the traditional cooking ones industries that have high returns such as such as boiling and frying. In recent the pharmaceutical industry. Its use in times, other products have been food industry may not be economically made from sweet potato such as jam viable. It is therefore important that chipati and mandazi (traditional foods methods that ensure maintenance of in Kenya). In Ghana, it is used as an quality of sweet potato for use in food adjunct in the production of abolo or are sought for. abodo which are steamed and baked products, respectively, with maize as Processing Needs of the main ingredient. Sweet Potato In western Kenya sweet potato In addition to the nutritional significance utilization is reported (Nungo et al., of sweet potato discussed earlier, it is 2007) to be limited to boiling, roasting reported to have anti-diabetic property and chewing uncooked tuber for a long and the components contributing to this time. Attempts have been made to add effect have been isolated and studied value to the tuberous root by processing from white-skinned sweet potatoes sweet potato into different products. In (Kusano et al., 2000). As a result of these a recent study in Kenya (Nungo et al., fine properties, various efforts have 2007), several products were prepared been made to process it into forms that from sweet potato including snack foods deliver the most benefits to consumers. and juice (Technically, the product Indeed, it is an under-utilized crop so would be described as drink, since juice the efforts made have concentrated on is the plant product extract without any increasing the utilization by increasing external material such as water and the food base. Farmers traditionally sugar). Most of the foods developed chip or crush sweet potato roots and had high acceptability among panellists sun-dry them for storage and use all who were made up of extension agents. year round. Chipping, drying, and The foods included crackies, a product storing orange-fleshed sweet potato made from a combined sweet potato, can overcome seasonal shortages of maize and beans and the so called juice. pro-vitamin A in the diets of many low The study also showed that products income African households during the with a combination of sweet potato dry season when there are no fresh, and cassava flour were more preferred 316 Protein and Beta-carotene in Maize-Sweet Potato

to pure wheat products (Nungo et al., Sweet potato starch has also 2007). been used in noodle production. Recent world-wide interest Physiochemical properties of four types in sweet potato has resulted in of sweet potato starch (SPS) and mung experimenting with processing into bean starch (MBS), and their blends for convenience forms, composite flours, noodle production were accessed by purees or into products that have Thao and Noomhorm (2011). Among wide acceptability such as pasta all sweet potato varieties, the white (Gopalakrishnan et al., 2011). For skin and yellow-red flesh colour sweet example, Gopalakrishnan et al. (2011) potato variety was found to be the most used three different protein sources suitable for noodle production due to its – whey protein concentrate (WPC), highest starch yield (17%) and starch defatted soy flour (DSF), and fish purity as well as the best starch colour powder (FP) – in combination with (Thao and Noomhorm, 2011). The MBS sweet potato starch in making pasta. noodle quality was found to be superior Of the three protein sources, WPC to SPS noodle quality, and blending gave high quality pasta with strong SPS with MBS for noodle production starch-protein network formation, resulted in markedly reduced quality. as evidenced from scanning electron However, the quality of noodles made microscopic studies and low in-vitro from mixture of 20% SPS and 80% MBS starch digestibility (Gopalakrishnan et was not significantly different from that al., 2011). Similarly, protein nutritional of MBS noodles (Thao and Noomhorm, quality was found to be high for WPC- 2011). For noodles prepared from fortified sweet potato pasta. The WPC- mixture of 20% SPS and 80% MBS, fortified sweet potato pasta in addition the most suitable initial solid content of showed very high scores for lysine starch slurry and aging time at 4˚C were and leucine as well as high essential 35% and 10-20 h, respectively. amino acid index and calculated protein Sweet potato is also becoming efficiency ratio (Gopalakrishnan et al., increasingly popular as an alternative 2011). Fractionation of starch showed raw material for the production of that the WPC-fortified sweet potato French fries (Garcia and Walter, 1998), pasta had the lowest rapidly digested and sweet potato chips is gaining wide starch (RDS) and the highest resistant acceptability. The French fries and starch (RS) content, indicating its crisps are potential nutritionally rich potential as a low glycaemic food. snack foods when produced from sweet Protein and Beta-carotene in Maize-Sweet Potato 317

potato cultivars high in provitamin A better appearance compared to the and ascorbic acid (Nafeesa et al., 2012). remaining two (the two showed similar Sweet potatoes are reportedly high in sensory scores), there was essentially energy, dietary fiber, potassium and no significant difference in the overall vitamin C, and low in fat (Hagenimana sensory attributes of crisps made from et al., 1993). The starch content of the the three cultivars used in the study fresh roots was reported to vary from (Nafeesa et al., 2012). 6.9% to 30.7% (Tian et al., 1991). Current Trend in Sweet Some of the advantages of Potato Processing producing different products from Worldwide, there is a gradual but sweet potatoes include greater variety significant move towards processing of and convenience. The use of the red- sweet potato tubers. For example, in fleshed sweet potato for the production China small holder farmers, who have of French fries and crips would further long cultivated sweet potato as a food enhance nutrition of the consumers security crop, processed roughly half of (Nafeesa et al., 2012). Nafeesa et al. their annual harvest of 118 million mt (2012) consequently studied the effect (1995–97 value) into animal feed (Scott of cultivar (white and orange fleshed) et al., 2000). It was estimated that these on the quality attributes of sweet potato farmers convert another 20 to 30 percent fries and crisp. The three cultivars used of annual sweet potato output into in the study showed proximate and starch for noodles and other processed pasting properties that were typical of products (Huang 1999; Timmins et al. sweet potato tubers, flour and starches 1992) and fries and chips. Indeed, the (Nafeesa et al., 2012). However, they processing of sweet potato into food showed significant (p < 0.05) difference has not been limited to conventional in their maltose (0.05% – 0.08%) and high starchy foods such as pasta and sucrose (0.05% – 1.60%) contents. The noodles. It has also included fermented amylose and amylopectin contents of products. For example, a curd-like sweet potato starches were 19.5% – product was prepared by fermenting 24.6% and 75.4% – 80.5%, respectively boiled anthocyanin-rich sweet potato (Nafeesa et al., 2012). Swelling power puree and cow milk with curd (starter) and solubility were 2.42 – 2.88 and 0.11 culture (Lactobacillus bulgaricus, – 0.32, 5.01 and 0.02 – 3.00 for flours Streptococcus lactis, St. diaceticlactis, and starches, respectively. Although etc.) by Panda et al. (2006). one of the cultivars showed significantly 318 Protein and Beta-carotene in Maize-Sweet Potato

The different concentrations of to manufacture baby foods (Woolfe, sweet potato puree used did not show 1992). The product has advantages variations in some important quality as infant food over other cereal based characteristics of curd such as pH, baby foods, especially wheat and wheat titratable acidity and lactic acid (Panda related cereals, due to its hypoallergenic et al., 2006). However, it was the curd effect (Maleki, 2001). This is especially with 8-12% sweet potato puree that so since many are developing cereal was most preferred by a consumer’s related diseases or allergic reaction to panellist (Panda et al., 2006). The wheat products. The pureeing of sweet authors report that the addition of potato for use as weaning food could sweet potato puree (8-12%) to the curd provide some advantages in resource made it quite firm and imparted flavour, poor and developing countries. In many body/texture, minerals, nutrients, developing countries, infant foods are antidiabetic substances, anthocyanin prepared from locally available sources pigments (antioxidant), dietary fibres mainly cereals, roots and tubers, which and starch (Panda et al., 2006). The are served as thick porridges (Sanni lactic acid bacterial counts in the curd et al., 1999). Just like other weaning having 8 and 12% sweet potato after 18 foods from root and tubers and cereals, h fermentation were 5x107and 7x107 sweet potato puree could be thick and (CFU ml-1), respectively (Panda et al., using it to meet the energy need of the 2006), evidencing support for lactic developing infant may be a challenge. acid bacteria growth and imparting It is important that the textural and probiotic property to the developed viscoelastic properties are investigated product. Indeed, the low concentration with a view of improving the quality of between 8 – 12 % that was used in characteristics of the product thus the product might make sweet potato developed so as to provide the most qualify as an adjunct in the product benefit to consumers, in this case developed. infants. Investigation of sweet potato for Ahmed and Ramaswamy use in the production of weaning foods (2006) studied dynamic mechanical for infants has also been undertaken. One spectroscopy and steady-shear product made from sweet potato that is rheological properties of sweet potato used for this is puree. Pureeing of sweet puree based food manufactured by potato is carried out on a large scale in Heinz Canada. The study was carried the United States with most of it utilized out to evaluate viscoelastic properties Protein and Beta-carotene in Maize-Sweet Potato 319

of the commercial sweet potato puree among lower-income consumers for infant food using a controlled stress processed food and snacks made rheometer. It was found that the puree from sweet potato (Scott et al., 2000). behaved like an elastic solid with G’ Improved production and postharvest predominating over G” (G’ > G”). The technologies as well as institutional elastic and viscous moduli decreased and policy innovations were suggested with an increase in temperature while as factors that could facilitate increases an abnormal increase in G’ was noticed in output and productivity that match at 65˚C. Steady shear viscometry, the increases in consumption (Scott et covering the shear rate range 0.1 to 100 al., 2000). s1, generally indicated the presence Scott et al. (2000) reported that of yield stress. The complex shear concerted international efforts were viscosity (g) and apparent viscosity (g) being undertaking to increase dry matter decreased with temperature between content and yield, exploit national 5 and 50˚C. The authors (Ahmed and international germplasm for and Ramaswamy, 2006) attributed a appropriate postharvest characteristics, deviation in rheological behaviour at including starch quality and pre-β and above 65˚C to the likely occurrence carotene content, and systematically of gelatinization and possible amylase– support national efforts to foster greater lipid complex formation of sweet product development for sweet potato potato starch as was confirmed by two by small – and medium-scale farmers distinct dynamic scanning calorimetry and entrepreneurs. Again in respect of (DSC) thermal transitions peaks (57 research needs, the authors (Scott et and 94.5˚C). al., 2000) suggested that because sweet potato cultivation is often concentrated Increased Processing in the poorest growing areas and among Need of Sweet Potato farmers with limited-resources, an Accessing the consumption potential of evaluation of the impact of sweet potato sweet potato, Scott et al. (2000) observed research on the food consumption and that East and Southern Africa will income-earning activities of the poorest show steady increases in consumption, countries should be considered (Scott et but more modest in volume compared al., 2000). to cassava. It was suggested that The effort as mentioned by Scott the anticipated consumption trend et al. (2000) to foster greater product will be reinforced by market niches development suggests the existence of 320 Protein and Beta-carotene in Maize-Sweet Potato

needs for product development in sweet fermentation is proteolytic in nature potato. Indeed, that potential exists and occurs in protein-rich foods such especially in developing countries. In as seeds and legumes and fish, where doing this, tools that can be employed it is used. Indeed, cereals and milk are are those the indigenes are familiar with predominantly fermented by lactic acid and comfortable with because of long bacteria. One cereal that is fermented exposure and association with them. in most part of West Africa is maize. Indeed, fermentation as a tool in food Fermentation of maize essentially processing has been used by people in involves soaking of cleaned grains for Africa and Asia. The process delivers 1 – 3 days in clean water, draining the many benefits to foods. The section water and milling the hydrated and that follows discusses how the tool has hydrolysed grain into a meal. The meal been used in many African foods and is them made into dough by addition of the benefits associated with it. water and mixing to uniformity. This is allowed to ferment at room temperature Fermented Foods in Africa for 2 to 3 days. The product so produced Food crops that serve as substrates can be used for preparing gruels (akasa of fermented foods in Africa include and koko) or dumplings such as kenkey, such ones as maize, millet, sorghum banku and ogidi (Mensah, 1997). The and oil seeds. It is generally accepted dumplings made from the fermented that there are three main fermentation maize dough are essentially wet processes: alcohol, lactic acid and cooked maize/corn bread. Other high alkali fermentation (Steinkraus, 1991). carbohydrate agricultural produce is Alcohol and lactic acid fermentation also fermented in many African states. are closely related since they both For example, cassava is fermented first occur in carbohydrate rich foods. by peeling, grating /milling the peeled However, while yeast is the dominant and washed root into paste and the paste microbial organism in alcohol allowed to ferment sometimes by use fermentation effecting changes in the of a starter culture that is locally called carbohydrate, mainly sugar, to produce kudeme (Amoa-Awoa et al., 1995) alcohol, in lactic acid fermentation, it which is prepared from cassava. is a group of lactic acid bacteria that The fermented dough serves as act upon the carbohydrate via the adjunct to maize dough in the preparation enzymes they produce that result in of banku. A similar fermented cassava the changes in the produce. Alkali dough that is made from coarsely grated Protein and Beta-carotene in Maize-Sweet Potato 321

cassava dough and packed into sacks to (1991) reported that a fermented cereal ferment with concomitant draining of gruel common in Zimbabwe showed water is subsequently sieved to remove marked inhibition of Campylobacter bigger fibre and roasted in large trays on jejuni and pathogenic Escherichia controlled fire into grains. This roasted coli at 30 minutes and 24 hours product is called gari (Whitby, 1968) respectively when the organisms were both in Ghana and Nigeria. introduced into them. A related study The preceding treatise about in Ghana using fermented maize dough fermentation is just an illustration of the significantly reduced the numbers extent of use of fermentation as a tool of Shigela flexneri, enterotoxigenic to in processing and bringing variety Escherichia coli and Campylobacter to foods that are consumed in Africa jejuni four hours after the introduction and elsewhere. Indeed, fermentation (Mensah et al., 1991). One factor that as a tool imparts several beneficial could contribute to the antimicrobial properties to foods when used. Apart of activity of fermented maize is the the changes to the aesthetic properties pH as is evident in other fermented by way of texture and flavour, some products from lactic acid fermentation have antimicrobial properties that are (Jay, 1986; Cuk et al., 1987). However, beneficial to consumers. For example, the pH may not be the only factor in Southern Ghana, a study on weaning imparting antimicrobial activity to and growth in infants 1 – 6 months old fermented foods as demonstrated by (Armar-Klemesu et al., 1991) found studies carried out by Mensah et al. that the infants that had porridge made (1991). The combined and synergistic from fermented maize dough did not activities of lactic acid bacteria have have any case of diarrhoea three months been suggested as the reason for the into the introduction and diarrhoea antimicrobial activity of fermented incidence after that was not related to foods. The homofermentative the introduction of the weaning food. organisms ferment sugar into lactic acid Indeed there was more for the above while the heterofermentative bacteria mentioned study (Armar-Klemesu et in addition to lactic acid produce a large al., 1991) reported in addition that the variety of terminal metabolites such as highest growth among the infants was acetic acid, diacetyl ethanol etc. (Berk, observed in the infants receiving early 1976). It has therefore been suggested fermented porridge. that residual ethyl alcohol that remains Similarly, Simango and Rukure after losses through the various 322 Protein and Beta-carotene in Maize-Sweet Potato

handling steps during processing of doughs were made with ratio of 80:20, fermented food could together with 70:30, and 60:40 weight by weight in other by-products inhibit the growth of incremental order of sweet potato and undesirable bacteria (Mensah, 1991). allowed to ferment for 48 hours at From the foregoing, it is evident that room temperature (25 – 28˚C). Non- fermentation produces a lot of benefits combined doughs from sweet potato in foods and can be used to improve and maize were also prepared using the quality of foods. Its application to the same approach. Doughs were oven tuberous roots of sweet potato has not – dried at 55⁰C to a moisture content been investigated, at least to the best of of 7-10%, milled and sieved through a our knowledge. 600μm mesh sieve to obtain the flour. It is with this background that This was used for further analysis. we decided to employ fermentation Crude Protein Determination in the processing of sweet potato in Protein content was determined combination with maize. The objective according to the Kjeldahl method was to develop an ingredient that could (AOAC, 1990). Samples (0.2 g) serve various purposes as weaning food were digested in 4.5 ml concentrated for infants, pro-vitamin A rich food for sulphuric acid and 3 g of catalyst mixture possible utilization as a substitute to (K SO and Selenium) at 370⁰C in a vitamin A supplementation and food for 2 4 Kjeldahl flask. It was then distilled by the diabetic as sweet potato has been adding 25 ml of 40% NaOH into 5 ml of found to be rich in resistant starch. boric acid with methyl orange indicator. Materials and Methods The distillate (50 ml) was titrated with Maize (Zea mais) gains were obtained standardized 0.1N sulphuric acid to and cleaned to remove unwholesome pink end point. This was done in four grains as well as any foreign materials replicates. Percentage protein was present. This was washed and steeped calculated by applying a factor of 5.7 for 18-24 hours. The steeped maize was to the total nitrogen measured per washed and wet-milled into meal with replicate. an attrition mill. Yellow fleshed sweet Beta-carotene Determination potato tubers bought from a local farmer The method reported by were sorted to remove the unwholesome Rodriguez-Maya and Kimura (2004) ones, washed, peeled, sliced and wet- was used with slight modification milled into dough. Maize-sweet potato Protein and Beta-carotene in Maize-Sweet Potato 323

to suit laboratory conditions. A was entered into SPSS WINDOWS. suspension of flour samples and cold Descriptive statistics and ANOVA were acetone (2 g/50 ml) was prepared and used to analyze the data. mixed for 1 minute. This was filtered Results and Discussion under vacuum by a sintered funnel. The results in Tab1e 1 show It was repeated until the residue was the β-carotene (mg/100g) content of colourless. The extract was partitioned Maize-Sweet Potato composite flours. into petroleum ether (PE). It was first The Maize – Sweet Potato composite washed with 300 mL distilled water flour of ratio 60:40 had the highest by pouring it gently along the wall β carotene (10.03 mg/100g) among of separatory funnel and discarding - the three combinations (80:20, 70:30, the lower phase without any shaking. and 60:40). Burgos et al. (2001) had This was followed with four additional indicated that β-carotene content washings with distilled water each 200 ranged from 0.0 to 0.04 mg/100g mL and discarding the lower phase in in cream coloured sweet potato and each case. In the last washing, the lower 4.29 mg/100g to 18.55mg/100g in phase was discarded as completely as deep orange coloured sweet potatoes. possible. The PE phase was collected Hacineza et al. (2010) similarly found by passing the solution through a small the orange fleshed sweet potato to have funnel containing anhydrous sodium higher β – carotene content than the sulphate. The separatory funnel was yellow fleshed. However, in this study, washed with PE and passed through the yellow fleshed variety was used the sodium sulphate into the collected but it was found to have very high β extract. The extract was concentrated – carotene content. The reason for the in a rotary evaporator and dried in N . 2 high β carotene in the present work It was redisolved in 1 mL HPLC grade – is not readily discernible. It is possible acetone and filtered through a 0.22mm that the different processing methods PTFE syringe filters into sample vials may be a factor. In the present work, the before injection. The prepared extract sweet potato was milled and fermented. was run on Waters ODS 2, 3 μm, 4.6 x It is possible that some factors that 150 mm C column with acetonitrile- 18 results in degradation of β carotene methanol-ethyl acetate (80:10:10) in - were removed during the fermentation 0.05% triethylamine as the mobile period. phase at a flow rate of 0.7 mL/min. Data 324 Protein and Beta-carotene in Maize-Sweet Potato

Table 1: β-Carotene content of Maize-sweet potato flours

Samples Mean ±SD β-carotene (mg/100g) 100% M 1.192 ± .002e SP 100% 18.261 ±.001a M:SP 80:20 1.785 ± .005d M:SP 70:30 4.642 ± .003c M:SP 60:40 10.030 ± .001 b n=4 p<0.01 M: Maize, SP: Sweet Potatoes. Values with different alphabets are signifi- cantly different at α ≤ 0.01.

Crude Protein Content dough for all the three (3) maize – sweet of Maize-Sweet Potato potato combinations (80:20, 70:30, and composite flour 60:40). Table 2 shows means , standard Earlier result reported by in our deviation and ANOVA of the laboratory (Tandoh et al., 2013) which percentage Crude Protein Content showed comparatively higher protein of Maize – Sweet potato composite for the three sweet potato-maize dough flours. The analysis shows that there combinations informed the choice was significant difference between the of the three combination used in the percentage crude protein content in the current work. Indeed, this was a follow maize-sweet potato flour of ratio 60:40 up to the earlier investigation and it (mean: 8.213 ± 0.222) and 80:20, (9.576 was to find out the β-carotene of the ± 0.330) but not with that of 70:30 composite flours formed from the two (mean: 7.798 ± 0.334) at 0.01 alpha differently categorized plant materials level. Also percentage crude protein which have a potential of contribution of sweet potato (mean= 5.24±.60) to addressing vitamin A deficiency was significantly lower than the other problem among the resource poor four (4) treatments (maize only, maize in developing countries. The protein sweet potato ratios 80:20, 70:30, and content of the composite flour with 60:40). However, Hacineza et al. high beta carotene was important in the (2010) found a 2.4% protein content of study because earlier work has shown yellow – fleshed sweet potato. Tandoh that conversion of β – carotene to retinol et al. (2013) found 12.5% protein of is lower in protein deficient rats (Parvin maize – sweet potato (yellow fleshed) and Sivakumar, 2000). flour after 48 hours fermentation of the Protein and Beta-carotene in Maize-Sweet Potato 325

Table 2. Crude Protein Content of Maize – Sweet potatoes composite flour ±SD Flour Samples Mean (% protein) Maize (M) only 8.65±.33b Sweet Potato(SP) only 5.24±.60d M:SP( 80:20) 9.58±.33 a M:SP (70:30) 7.80±.33c M:SP (60:40) 8.2±.22c n=4 *p < 0.05 ** p < 0.01. Values with different alphabets are significantly different at α ≤ 0.01

The result shows that the β-carotene at 48 hours, improves the β-carotene (mg/100g) in maize-sweet potato flour content of the composite flour. of ratio 60:40 was the highest compared Conclusion to the other two maize-sweet potato The results of the study indicate that combinations (80:20 and 70:30). For fermentation of combined maize – the percentage crude protein content, sweet potato flour has the potential of the maize-sweet potato flour of ratio delivering ingredients that have good 80:20 showed the highest compared vitamin A and proteins contents. The to the other two combinations (60:40, 60:40 maize-sweet potato composite and 70:30). The 60:40 maize-sweet fermented flour seems to have edge over potato combination fermented for 48 the other two combinations studied and hours relatively contained the highest could be used in improving vitamin A β-carotene content indicating that status of resource poor communities in fermentation of the maize-sweet potato Ghana and other developing countries that have vitamin A deficiency problem. 326 Protein and Beta-carotene in Maize-Sweet Potato

REFERENCES

Adebowalea, K. O., Olu-Owolabi, B. I., Olayinka, O. O., & Lawal, O. S. (2005). Effect of heat moisture treatment and annealing on physicochemical properties of red sorghum starch. African Journal of Biotechnology, 4(9). Ahmed, J., & Ramaswamy, H. S. (2006). Viscoelastic properties of sweet potato puree infant food. Journal of Food Engineering, 74(3), 376-382. Ameny, M. A.,and Wilson, P. W. (1997). Relationship between Hunter color values and b-carotene contents in white-fleshed African sweetpotatoes (Ipomoea batatas Lam). Journal of the Science of Food and Agriculture, 73(3), 301-306. Amoa‐Awua, W. K. A., & Jakobsen, M. (1995). The role of Bacillus species in the fermentation Fof cassava. Journal of Applied Bacteriology, 79(3), 250-256. Amoah, R. S., Teye, E., Abano, E. E., & Tetteh, J. P. (2011). Effect of pre-storage treatment on the shelf-life of TIS 2 sweetpotato variety. Journal of Agriculture and Biological science, 6(4), 9-12. Bertolini, A. C., Mestres, C., & Colonna, P. (2000). Rheological properties of acidified and UV‐irradiated starches. Starch‐Stärke, 52(10), 340-344. A.O.A.C. (1990). Official Methods of Analysis, 15th Ed., Washington, D. C. Association of Official Analytical Chemists. Armar-Klemesu, M. A., Wheeler, E. F., Brakohiapa, L. A., & Yamamoto, S. (1991). Infant feeding and growth in rural Ghana: is the use of the traditional fermented porridge a case for early supplementation? Journal of tropical pediatrics, 37(3), 111-115. Bachman, S., Gambus, H., & Nowotna, A. (1997). Effect of gamma-radiation on some physico-chemical properties of triticale starch. Polish journal of food and nutrition sciences, 6(3), 31-36. Burgos, G., Rossemary, C., Cynthia, S., Sosa, P., Porras, E., Jorge, E., & Wolfagang, G. (2001). A color chart to screen for high beta-carotene in Orange fleshed sweet potato breeding. Cairo: International Potato Center. Čuk, Z., Annan‐Prah, A., Janc, M., & Zajc‐Satler, J. (1987). Yoghurt: an unlikely source of Campylobacter jejuni/coli. Journal of Applied Bacteriology, 63(3), 201-205. Ewell, P. T. (1990). Sweetpotatoes in Eastern and Southern Africa. In Workshop on Sweet Potatoes in the Food Systems of Eastern and Southern Africa, Nairobi, Kenya. Protein and Beta-carotene in Maize-Sweet Potato 327

Falade, K. O., Ighravwe, E., & Ikoyo, S. S. (2011). Physico‐chemical characteristics of non‐irradiated and γ‐irradiated yams cultivars (Dioscorea rotundata, Dioscorea alata) and sweet potato (Ipomoea batatas (L) Lam). International Journal of Food Science & Technology, 46(6), 1186-1193. Ferguson, E. L., & Darmon, N. (2007). Traditional foods vs. manufactured baby foods. In Issues in Complementary Feeding (Vol. 60, pp. 43-63). Karger Publishers. Garcia, A. M., & Walter Jr, W. M. (1998). Physicochemical characterization of starch from Peruvian sweetpotato selectionsASA Alimentos SA, Lima, Peru. Starch‐ Stärke, 50(8), 331-337. Gerster, H. (1993). Anticarcinogenic effect of common carotenoids. International Journal for Vitamin and Nutrition Research, 63, 93-93. Ghana Health Service (1997). Survey on clinical citamin A deficiency in Ghanahttp:// www.tulane.edu/~internut/Countries/Ghana/ghanavitamina.html Gopalakrishnan, J., Menon, R., Padmaja, G., Sajeev, M. S., & Moorthy, S. N. (2011). Nutritional and functional characteristics of protein-fortified pasta from sweet potato. Food and Nutrition Sciences, 2(9), 944. Hagenimana, V., Carey, E. E., Gichuki, S. T., Oyunga, M. A., & Imungi, J. K. (1998). Carotenoid contents in fresh, dried and processed sweetpotato products. Ecology of Food and Nutrition, 37(5), 455-473. Hallman, G. J. (2001). Ionizing irradiation quarantine treatment against sweet potato weevil (Coleoptera: Curculionidae). Florida Entomologist, 84(3), 415. Hacineza , E., Vasanthakaalam, H., Ndirigwe J., & Mukwantali, C (2010) A Comparative study on the β-carotene content and its retention in yellow and orange fleshed sweet potato flours. ISAR, Rwanda. IAR (Institute of Agricultural Research) (2009). Sweet potato in Sierra Leone. Institute of Agricultural Research, Njala Research Station, Njala. Sierra Leone. Jay, M. J. (1986). Modern Food Microbiology. Fermented Foods and Related Products of Fermentation. 239-255 and 362-406. Kennedy, E. T., & Oniang’o, R. U. T. H. (1993). Household and preschooler vitamin A consumption in southwestern Kenya. The Journal of nutrition, 123(5), 841. Kusano, S. (2000). Antidiabetic activity of white skinned sweet potato (Ipomoea batatas L.) in obese Zucker fatty rats. Biological and pharmaceutical bulletin, 23(1), 23- 26. Lewthwaite, S. L., & Triggs, C. M. (1995). Sprout suppression in sweetpotato roots following immersion in sodium hypochlorite solutions. New Zealand journal of crop and horticultural science, 23(3), 283-287. Lii, C. Y., & Chang, S. M. (1978). Studies on the starches in Taiwan. 1. Sweet potato, cassava, yam, and arrowroot starches. In Proc. Natl. Sci. Council, Republic of 328 Protein and Beta-carotene in Maize-Sweet Potato

China (Vol. 2, pp. 416-423). Liu, Q., Donner, E., Yin, Y., Huang, R. L., & Fan, M. Z. (2006). The physicochemical properties and in vitro digestibility of selected cereals, tubers and legumes grown in China. Food Chemistry, 99(3), 470-477. Low, J. W. (1997). Combating Vitamin A Deficiency Through the Use of Sweet Potato: Results from Phase I of an Action Research Project in South Nyanza, Kenya. International Potato Center. Lu, G., Huang, H., & Zhang, D. (2006). Prediction of sweetpotato starch physiochemical quality and pasting properties using near-infrared reflectance spectroscopy. Food chemistry, 94(4), 632-639. Lu, J. Y., White, S., Yakubu, P., & Loretan, P. A. (1986). Effects of gamma radiation on nutritive and sensory qualities of sweet potato storage roots. Journal of food Quality, 9(6), 425-435. Maleki, S. (2001). The big eight food allergens. Dietitian’s Edge, 2, 57-60. Maziya-Dixon, B., Sanni, L. O., Adebowale, A. A., Onabanjo, O. O., & Dixon, A. G. O. (2005, December). Effect of variety and drying methods on proximate composition and pasting properties of high quality cassava flour from yellow cassava roots. In Proceedings of the African Crop Science Society Conference, Enttebe, Uganda (pp. 5-9). Mbeza, H., Minde, I., & Mjiku, C. (1997). Sweetpotato storage and its economy in Malawi. In 4th African Potato Association Congress at University of Pretoria, pp24-28. Mensah, P. (1997). Fermentation—the key to food safety assurance in Africa? Food Control, 8(5), 271-278. Mensah, P., Tomkins, A. M., Drasar, B. S., & Harrison, T. J. (1991). Antimicrobial effect of fermented Ghanaian maize dough. Journal of Applied Bacteriology, 70(3), 203- 210. Millward, D. J., & Jackson, A. A. (2004). Protein/energy ratios of current diets in developed and developing countries compared with a safe protein/energy ratio: implications for recommended protein and amino acid intakes. Public health nutrition, 7(03), 387-405. Moyo, C., Benesi, I., Chipungu, F., Mwale, C., Sandifolo, V., & Mahungu, N. (2004). Africa: Cassava and Sweetpotato yield in Malawi. Afr. Crop Sci. J, 12, 295-303. Nafeesa, A., Kolawole O, F., & John O, A. (2012). Effect of cultivar on quality attributes of sweet potato fries and crisps. Food and Nutrition Sciences, 2012. Narayana, K., & Rao, M. N. (1984). Effect of partial proteolysis on the functional properties of winged bean (Psophocarpus tetragonolobus) flour. Journal of Food Science, 49(3), 944-947. Protein and Beta-carotene in Maize-Sweet Potato 329

Nungo, R. A., Ndolo, P. J., Kapinga, R., & Agili, S. (2007). Development and promotion of sweet potato products in Western Kenya. In Proceedings of the 13th ISTRC Symposium (pp. 90-794). Ocloo, F. C. K., Otoo, G., Nkansah, R. M., Mahami, T., Odonkor, S., & Quayson, E. T. (2011). Functional and physicochemical characteristics of starch obtained from gamma-irradiated sweet potato (Ipomea batatas L.). Journal of Agriculture and Food Technology, 1(7), 116-122. Oladebeye, A. O., Oshodi, A. A., & Oladebeye, A. A. (2009). Physicochemical properties of starches of sweet potato (Ipomea batata) and red cocoyam (Colocasia esculenta) cormels. Pakistan Journal of Nutrition, 8(4), 313-315. Onwueme, I. C. (1978). The tropical tuber crops: yams, cassava, sweet potato, and cocoyams. John Wiley and Sons. Panda, S. H., Naskar, S. K., & Ray, R. C. (2006). Production, proximate and nutritional evaluation of sweet potato curd. Journal of Food Agriculture and Environment, 4(1), 124. Pfander, H. (1992). [1] Carotenoids: An overview. Methods in enzymology, 213, 3-13. Parvin, S. G., & Sivakumar, B. (2000). Nutritional status affects intestinal carotene cleavage activity and carotene conversion to vitamin A in rats. The Journal of nutrition, 130(3), 573-577. Paton, J. E., & Scriven, F. M. (1989). Use of NAA to inhibit sprouting in sweet potatoes (Ipomea batatas). Journal of the Science of Food and Agriculture, 48(4), 421-427. Pinstrup-Andersen, P., Burger, S., Habicht, J. P., & Peterson, K. (1993). Protein-energy malnutrition. Disease Control Priorities in Developing Countries, Jamison, DT, Mosley, WH, Measham, AR and Bobadilla, JL, ed. Oxford University Press, Oxford, 391-420. Rees, D., Kapinga, R., & Oirschot, V. Q. (Eds.). (2003). Sweet potato post-harvest assessment: experiences from East Africa. International Potato Center. Rodríguez-Amaya, D. B. y Kimura, M. 2004. Harvestplus Handbook for Carotenoid Analysis. HarvestPlus Technical Monograph 2. Washington, DC and Cali: International Food Policy Research Institute (IFPRI) and International Center for Tropical Agriculture (CIAT). Roels, O. A., & Trout, M. Dujacquier, 1958, Carotene balances on boys in Ruanda where vitamin A deficiency is prevalent. J. Nutr, 65, 115-127. Rose, C. J. (1979). Comparison of single and progressive harvesting of sweetpotato (Ipomoea batatas (L) Lam.). Papua New Guinea Agricultural Journal. Parveen, S., & Hafiz, F. (2003). Fermented cereal from indigenous raw materials. Pakistan journal of nutrition, 2(5), 289-291. Sanni, A. I., Onilude, A. A., & Ibidapo, O. T. (1999). Biochemical composition of infant 330 Protein and Beta-carotene in Maize-Sweet Potato

weaning food fabricated from fermented blends of cereal and soybean. Food chemistry, 65(1), 35-39. Scott, G. J., Rosegrant, M. W., & Ringler, C. (2000). Roots and tubers for the 21st century: Trends, projections, and policy options (Vol. 31). Intl Food Policy Res Inst. Simango, C., & Rukure, G. (1991). Survival of Campylobacter jejuni and pathogenic Escherichia coli in mahewu, a fermented cereal gruel. Transactions of the Royal Society of Tropical Medicine and Hygiene, 85(3), 399-400. Simon, P. W. (1997). Plant pigments for color and nutrition. HortScience: a publication of the American Society for Horticultural Science (USA). Smit, N. E. J. M. (1997). Integrated pest management for sweetpotato in Eastern Africa. Smit. Steinkraus, K. H. (1991). African alkaline fermented foods and their relation to similar foods in other parts of the world. Traditional African foods: quality and nutrition. New York: Marcel Dekker, 87-92. Tandoh, I., Quayson, E.T. & Adinortey, M. B. (2013) Process Optimization of Maize- Sweet Potato Composite Flour. A paper presented at the 28th Biennial conference of Ghana Science Association, in Accra Ghana on July 14-19 , 2013 at University of Ghana, Legon. Teye, E. (2014). Developing appropriate storage technology for sweet potatoes (Ipomoea batatas lam) in the coastal savannah zone of Ghana. Thao, H. M., & NOOMHORM, A. (2011). Modeling and effects of various drying methods on sweet potato starch properties. Walailak Journal of Science and Technology (WJST), 8(2), 139-158. Tian, S. J., Rickard, J. E., & Blanshard, J. M. V. (1991). Physicochemical properties of sweet potato starch. Journal of the Science of Food and Agriculture, 57(4), 459- 491. Timmins, W. H., Marter, A. D., Westby, A., & Rickard, J. E. (1992). Aspects of sweetpotato processing in Sichuan Province, People’s Republic of China. In International workshop on root and tuber crop processing, marketing, and utilization in Asia, Baybay (Philippines), 22 Apr-1 May 1991. CIP. Wall, M. M. (2004). Compositional and sensory analyses of sweetpotatoes after x-ray irradiation quarantine treatment. HortScience, 39(3), 574-577. Whitby, P. (1968). Foods of Ghana. World Health Organization. (1995). The global prevalence of vitamin A deficiency. Micronutrient deficiency information system (MDIS) working Paper 2. WHO/ NUT/95.3. Geneva: WHO. Woolfe, J. A. (1992). Sweet potato: an untapped food resource. Cambridge University Protein and Beta-carotene in Maize-Sweet Potato 331

Press. Zhang, Z., & Corke, H. (2001). Trypsin inhibitor activity in vegetative tissue of sweet potato plants and its response to heat treatment. Journal of the Science of Food and Agriculture, 81(14), 1358-1363.

Acknowledgement: We are grateful the Nutrition Third World, Brussels, Belgium for their financial and technical support to this work on utilization of sweet potato in composite flour production. 332

Utilization of cassava peels as feed for ruminants in Ghana: A review of alternative methods of improving their nutritional value

Niayale1, R. and Addah1, W. and Ayantunde2 A. A. 1Department of Animal Science, University for Development Studies, P. O. Box TL 1882, Tamale, Ghana 2International Livestock Research Institute, BP 9478, Ouagadougou, Burkina Faso Correspondence: [email protected]

Abstract to intake. Main methods of reducing Cassava peel is a by-product from the HCN concentration and improving processing of cassava. It is very rich intake of cassava peels by ruminants include soaking, boiling, sun-drying, in metabolizable energy and highly ensiling and addition of sulphur. This degradable in the rumen. Cassava peels paper has reviewed empirical results are therefore a major supplementary from previous studies that employed feedstuff for feeding cattle, sheep and these alternative methods to improve goats in Ghana. The utilization of the nutritional value of cassava peels as cassava peels by ruminants is however ruminant feed. In Ghana, the commonest limited by their lower crude protein method of preserving cassava peels as feed for ruminants is sun-drying. content, hydrogen cyanide (HCN) Reduction in HCN concentration of concentration and poorer methods of cassava peels through ensiling is 10% conservation and storage that further higher than reduction through drying reduces their nutritional quality. but reduction in HCN by ensiling Hydrogen cyanide imposes bitterness compared to drying has not been on the peel, reduces its palatability consistent in previous studies. Ensiling and intake, and can cause depression also increases the protein content of of growth performance. Even though the peel, increases its digestibility ruminal microbes have been shown to be and improves growth rate of sheep. capable of detoxifying HCN; bitterness Other methods of reducing the effects of the peel can be a major constraint of HCN on livestock include dietary Utilization of cassava peels as feed for ruminants in Ghana 333

supplementation with sulphur. Cassava sustainability of small-scale ruminant peels cannot however be fed alone production systems. Agro industrial because their lower protein content by-products and crop residues are (4.5–6.0% DM) cannot support rumen commonly used as supplementary feed microbial growth, thereby warranting for ruminant production as these feed supplementation with other protein-rich resources are of lower food value to feedstuff such as cotton seed cake. Even man. though cassava peels are commonly fed Cassava peels are the by-products to ruminants in the dry form in Ghana, of cassava tuber processing. The peel ensiling the peel has been shown to accounts for 11% (Tewe et al., 1992) be more effective at enhancing its to 20% (Ifut, 1992) of the whole tuber. nutritional value compared to other In Ghana, the peels are readily and methods of preservation. cheaply obtained from almost all the Key words: Cassava peels, ensiling, agro-ecological zones where animals hydrogen cyanide, ruminants, sun- are reared. However, they are often drying either underutilized or under exploited. Production estimates in 2010 indicated Introduction that Ghana was ranked sixth in the world Livestock production in Ghana is and fourth in Africa in the production of constrained by many factors of which cassava (FAO, 2013). feed shortage during the dry season is The intake and utilization of ranked the greatest (Oppong-Anane, cassava peels by ruminants in the fresh 2013). The mainstay of the livestock state is limited by hydrogen cyanide industry in Ghana is natural pasture and (HCN). Hydrogen cyanide imposes crop residues, often left on the farm field bitterness on the peel and reduces its after harvest. The quality and quantity palatability and intake. It is toxic and of natural pasture however often decline can interfere with functions of metal- during the dry season to a point where it containing enzyme systems responsible is no longer able to adequately support for cell respiration and function animal growth performance without (Enneking & Wink, 2000), depress supplementation (Annor & Adongo, growth performance (Okafor, 2004) 1992). However, because of the high and cause death (Tewe and Iyayi, 1989). cost of conventional feedstuffs, agro- There are many processing methods to industrial by-products and crop residues reduce HCN concentration and increase have become very important in the the feeding value of the peels. Sun- 334 Utilization of cassava peels as feed for ruminants in Ghana

drying reduces HCN concentration by not be cost-effective at the smallholder 86% whereas fermentation (ensiling) level. Supplementary feedstuff obtained reduces it by 96% (Tewe, 1992). Cooke from agro-industrial by-products such & Maduagwu (1978) also reported that as those from grain processing such as bound HCN decreases during soaking. cereal brans and peelings of tuber crops Data from our recent studies (Addah et (yams, cassava and potatoes peels) are al., 2016; unpublished) suggest that total becoming popular as cheap sources HCN concentration of cassava peels was of energy or protein for meeting the reduced by sun-drying than by ensiling. nutrient requirements of cattle, sheep Indeed, Phuc et al. (1996) concluded and goats. However most of these by- that drying may be more effective at products contain anti-nutrients which removing HCN in cassava leaves than limit their feeding value. Cassava peels ensiling. Our data (Addah et al., 2016; have lower crude protein (3.8‒4.6%) unpublished) further indicated that compared to yam (5.6‒7.2%) but are though sun-drying was more effective at more digestible in vitro than yam peels reducing HCN concentration, ensiling (57.4‒68.4 vs. 43.0‒67.0%; Table 1). improved animal growth performance Utilization of cassava than drying. This can be attributed to peels as ruminant feed. the increase in crude protein content of Cassava peels are produced from the ensiled compared to dry peels. the processing of cassava roots Feed resources for ruminant into products such as cassava chips production in Ghana (konkonte), starch, “gari” and cassava The livestock industry in Ghana flour. Cassava peel is a cheap and depends mainly on natural growing alternative source of energy for feeding grasses, left-over crop residues and both ruminants and non‒ruminants. It is agro by-products. Nutritional quality very rich in metabolizable energy (ME) of natural forages however fluctuates and very well degraded in the rumen widely between the rainy season when (Smith, 1988). In situ DM degradability the value is high and the dry season of the dried peels at 24 h is 70% vs. 73% when they become lignified and of lower for the ensiled product (Asaolu, 1988). nutritional value (Konlan et al., 2016). Due to its high starch content, cassava The use of conventional feedstuff such peels can be added as a source of readily as maize, soybean cake and fish meal fermentable carbohydrate to improve as supplements to low quality feed may the energy concentration of tropical Utilization of cassava peels as feed for ruminants in Ghana 335

grass silage diets (Onua & Okeke, conserve them during the rainy season 1999). The peels are often a nuisance for use in the dry season. Changes in in some rural communities where they season have been shown to affect the are generated in large quantities. The nutrient composition of cassava peels major problem in such communities (Table 1) because of poor methods of is inadequate knowledge on their conservation and storage. utilization as animal feed and how to Table 1: Chemical composition of cassava and yam peels during different season in the Northern region of Ghana Item Season OM% CP% NDF% ADF% IVOMD% Early dry 94.6 3.8 35.9 12.9 60.1

Cassava Late dry 92.8 4.6 38.5 19.7 57.4 peels Early wet 93.3 4.4 42.1 17.9 68.4 Main wet 90.0 4.0 35.7 15.7 57.2 Early dry 95.0 6.5 79.2 9.5 67.0 Late dry 93.9 5.9 80.3 9.6 53.2 Yam peels Early wet 95.7 5.6 83.0 8.4. 70.3 Main wet 85.1 7.2 46.7 19.3 43.0

Source: Konlan et al. (2016) OM – organic matter; CP – crude protein; NDF-neutral detergent fibre; ADF – acid detergent fibre; IVOMD – in vitro OM digestibility Data was obtained from the 3 regions (Northern, Upper East and Upper West) of Northern Ghana during the early (November to January, 2013) and late (February to April, 2014) dry seasons, and the early (May to July, 2014) and main (August to Octo- ber, 2014) wet seasons. Cassava peel is low in CP and digestibility due to its overall higher ether extract but high in nitrogen free fibre content. The bulk of the tuber extracts (NFE), ash and crude fibre (90%) consists of carbohydrates made content (Table 1) making it a good up of 4.9–6.0% CP, and 68.5–77.9% energy source for livestock. The NFE (Table 2). This makes the peel a peels contain higher concentrations of particularly suitable energy source for cyanogenic glycosides and CP (< 5%) ruminants. It should not however be fed than other parts of the tuber (Lukuyu et alone because of the lower CP and ash al., 2014) but lower energy density and content cannot support optimum growth 336 Utilization of cassava peels as feed for ruminants in Ghana

of microbial organisms in the rumen. vitamin B (Oppong-Anane, 2013). Its optimal utilization requires sources Cassava peels have been found to be of readily fermentable protein and by- highly degraded in the rumen (81% pass protein as well as micronutrients DM; Smith, 1988). including sulphur, phosphorus, and Table 2: Nutrient composition of sun-dried cassava peels

Onyimonyi Constituent Smit h Sogunle et Heuzé et Addah Konlan et & Ugwu (%) (1992) al. (2009) al. (2012) (2005) al. (2016) (2007)

Dry matter 29.6 ‒ 80.95 28.0 -

Crude 4.9 4.5 5.5 4.8 6.0 4.4 protein

Crude fibre 16.6 7.0 21.36 21.0 9.74 -

Ether Extract 1.3 2.0 0.67 1.3 1.04 -

NFE 68.5 81.5 66.49 60.8 77.9 -

Ash 5.9 5.0 5.98 5.7 5.26 6.7

Methods of improving in water and addition of sulphur. the nutritional quality Sun-drying of cassava peels Sun-drying can detoxify cassava peels High doses of HCN above the threshold to tolerable levels (Ahamefule et al., of 3 mg/kg body weight can interfere with 2003). Tweyongyere & Katongole the utilization of essential amino acids (2002) examined three methods of and the functions of metal-containing detoxifying HCN in cassava peels; enzymes systems (Enneking & Wink, sun-drying, fermentation and soaking. 2000), depress growth performance It was concluded that sun-drying was (Okafor, 2004) and sometimes cause the most effective; it resulted in the death (Tewe & Iyayi, 1989), Methods most rapid reduction of HCN by more commonly used to reduce HCN than 82% in 48 h with levels reducing to concentration in feeds include sun- safer levels of <50 mg/kg in 72 h. Sun- drying, ensiling/fermentation, soaking drying resulted in a greater loss of total Utilization of cassava peels as feed for ruminants in Ghana 337

cyanide compared to laboratory oven- and other spoilage microorganisms drying (60°C) for 48h (Tewe & Kasali, such as Aspergillus flavus which 1986). Sun drying on sloped trays can be pathogenic (Clerk & Caurie, effectively removes much of the soluble 1968). Microbial growth exposes the cyanide compounds due to the slower consuming animal to aflatoxicosis and breakdown and less denaturation of the mycotoxic infection (Lukuyu, et al., linamerase enzyme that destroys the 2014). Drying can also result in loss cyanogenic glycosides (Gomez et al., of volatile nutrients such as vitamins. 1984). Sun-drying cassava leaves was To speed up the drying process, the also reported to reduce HCN content to material is first chopped to 3-5cm 22.5 mg/kg compared to 147 mg/kg for which allows for quicker evaporation the ensiled material (Phuc et al., 1996). of moisture and subsequent release of Phuc et al. (1996) therefore concluded volatile toxic substances such as HCN. that drying may be more effective at Not only is sun-drying cost-effective removing HCN than ensiling. Other compared to ensiling, the slower rate studies however showed that ensiling drying especially in the rainy season reduced free HCN of the peel by results in greater loss of bound HCN by 36% (Gomez & Valdivieso, 1988) to increasing the contact period between 98% (Tewe, 1992) compared to 82% the glucosidase and the glucoside in (Tweyongyere & Katongole (2002) the aqueous medium which causes to 85% (Gomez et al., 1984) by sun- hydrolysis of cyanogenic glucosides by drying. linamarase (Tewe, 1992; Lukuyu et al., Sun-drying is cost effective since 2014). Data from our laboratory in the it requires less capital expenditure University for Development Studies and labour as compared to the other indicated that sun-drying was more methods. However, sun drying is slow effective at reducing HCN than ensiling depending on the time of the year and (Addah et al., 2016; unpublished; Table often encourages the growth of mould 3) 338 Utilization of cassava peels as feed for ruminants in Ghana

Table 3: Effects of ensiling on fermentation characteristics of cassava peels after 45 d of ensiling in bag silos

Item Dried Ensiled SEM P value

pH 6.2 4.2 0.029 <.0001

Ammonia N (mg/kg DM) 0.48 1.12 0.365 0.229

HCN (mg/kg DM) 18.02 25.01 0.145 0.001

Source: Addah et al. (2016; unpublished)

Fig. 1: Effects of different methods of The microorganisms produced during conservation on average daily gain of fermentation are capable producing sheep (Addah et al., 2016; unpublished) linamarase which then hydrolyzes the glycosides hence reducing the cyanide Ensiling/fermentation content (Okafor, 1998). Fermentation The ensiling process causes can reduce HCN levels to safer levels disintegration of intact glucoside below 30 mg/kg (Tweyongyere & through cell disruption, a drop in pH Katongole, 2002). of the ensiled medium and an intense Ensiling/fermentation also helps heat generation that reduces moulding to improve the CP content of cassava (Lukuyu, et al., 2014). Gomez & peel silage. During fermentation, the Valdivieso (1988) reported that ensiling increase in growth and proliferation of cassava chips reduced the cyanide fungi or bacterial complex can lead to content to 36% of the initial value an increase in the protein content (Oboh, after an ensiling period of 26 weeks. Utilization of cassava peels as feed for ruminants in Ghana 339

2002). Indeed, we recently observed well as the additional cost of acquiring that ensiling cassava peels improved or constructing the silo. Ensiling also the ADG of sheep compared to drying improves the sensory characteristics as the peel (Fig. 1) even though HCN was well as pH of cassava peels. Ensiling lower in the dried cassava peels than the resulted in silage with a pleasant smell, ensiled peels used to formulate these firm texture and light brown to brown diets (Addah et al., 2016; unpublished). colour (Addah et al., 2016; unpublished; Fermentations of cassava peels with the Table 4). Meneses et al. (2007) reported pulp juice has been shown to increase a pH of 3.5–5.5 as acceptable for good CP in the peels from less than 2% to silage made from crop by-products. 13-26% (Adamafio et al., 2010) thus Asaolu (1988) also reported that good further enhancing potential feeding quality silage is produced when cassava value of the product. Ensiling has cost peels silage is light brown in colour, implication as compared to drying as firm in texture with a pleasant odour more labour is required for chopping, and a pH of 4.4 packing and compacting the silage as Table 4: Sensory characteristics of cassava peel silage after 45 d of ensiling in large bag silos in the Northern region.

Item Description Score1 Colour (1-15) Light brown 9.22±2.24 Smell (1-15) Very pleasant 10.50±2.46 Texture (1-10) Firm 8.00±2.10 Grade Good 27.72±0.72 pH Lower 4.12+0.03 Addah et al.(2016; unpublished) Values are means of three large silos (n = 3) The silages were graded by summing the scores for colour (1-15), texture (1-10) and smell (1-15) as excellent grade (40-31), good grade (30-21), general grade (20-11) and low-grade (≥10). (Jian et al., 2015; Jianxin, 2002).

Soaking soluble cyanide into the soaking water. Soaking provides a suitably larger Soaking removed about 20% of the free medium for fermentation which converts cyanide in fresh cassava chips after 4 or hydrolyses cyanogenic glycosides h (Tewe, 1992). Cooke & Maduagwu to cyanide and allows extraction of the (1978) reported that bound cyanide 340 Utilization of cassava peels as feed for ruminants in Ghana

begins to decrease only after the onset similarly has another disadvantage of of fermentation during soaking. A very nutrient loss through the leaching of significant reduction in total cyanide the nutrients into the cooking medium is achieved if the soaking water is (FAO, 1990). Boiling resulted in a 20- routinely changed over a period of 3-5 30% loss of vitamins C from unpeeled days (Tewe, 1983). Soaking has the roots and tubers (FAO, 1990). Boiling is combined effect of allowing cyanogenic also not cost effective and is impractical glycosides to come in contact with under smallholder systems and in large linamarase (Westby & Choo, 1994) scale applications due to the time and which initiates the hydrolysis of the resources involved. cyanogenic glycosides to form HCN Sulphur in hydrogen cyanide which is toxic. Water-soaking fresh (HCN) detoxification peels for 1-5 h followed by sun-drying Although the precise level of HCN that also significantly reduced cyanogenic causes toxicity is not known, levels glycosides in amounts proportional to below 50 mg/kg have been reported to be the duration of soaking (Shoremi et al., harmless and acute HCN toxicity is not 1999). common (Smith, 1992). Detoxification Boiling of HCN to thiocynate (non-poisonous) Boiling was able to remove about 90% is accomplished by sulphur-containing of free cyanide within 15 min. compared amino acids (e.g. cysteine) synthesized with 55% of bound cyanide after 25 in the rumen (Tewe, 1992) and/or ionic min. of boiling (Cooke & Madunagwu, or elemental sulphur in the liver (Smith, 1978). A 25-75% reduction of cyanide 1992). The latter found that 1.2 mg of was achieved by cooking/boiling but sulphur was required to detoxify 1.0 g this was dependent on cooking time HCN and recommended sulphur licks and chip size with the highest HCN as effective protection against chronic losses observed in smaller than larger HCN toxicity. Cassava contains chips (Nambisan & Sundaresan, 1985). cyanogenic glucosides, made up of Boiling is reported to be able to destroy 95% linamarin and 5% lotaustralin the linamarase enzyme (Tewe, 1992). (Conn, 1994). Prolonged boiling has also been reported Cyanogenesis is initiated when to denature or destroy the linamerase cassava tissue is physically disrupted enzyme at temperature of 72°C, leaving because cyanogens and cyanogenic the glycosides and HCN intact. Boiling enzymes (linamarase) are located in Utilization of cassava peels as feed for ruminants in Ghana 341

different compartments of the cell (Conn, reactions involved in detoxification 1994). Linamarin, the major cyanogenic of ingested cyanide includes; reaction glucoside is present in all tissues of the with cysteine to form iminothiozilidine cassava plant and is synthesized from compound that is excreted through the amino acid valine (Balagopalan et saliva and urine, conversion of cyanide al., 1988). Detoxification of cyanide to formic acid and excretion through can be achieved by converting it to a urine, and cyanide combining with relatively non-toxic product which hydroxyl cobalamine and excreted in is readily eliminated from the body. urine and bile Rhodanase a sulphur transferase The use of sulphur containing mediates the biotransformation of amino acids to detoxify cyanide to the cyanide to a much less toxic thiocyanate less toxic thiocyanate therefore causes (Sorbo, 1962) which is secreted into an increased demand for sulphur in the the blood steam and then excreted via diet (Maner & Gomez, 1973). Therefore, milk and urine. This process requires protein deficiency may result if there is sulphur donors such as dietary sulphur- low intake of methionine and cysteine containing amino acids. Exogenous that are used for the detoxification of supplementation of rhodanase in the HCN in diets containing cassava the form of sulphur donors has been (Osuntokun, 1981). Consequently, reported to accelerate the transulfuration excessive consumption of cassava as a of cyanide to thiocyanate (Cannon et main source of dietary energy and protein al., 1994). This detoxification requires can expose animals to cyanide toxicity. sulphur donors, which are provided Supplying sulphur licks to ruminants from sulphur-containing dietary amino effectively protected them against acids, cysteine and methionine as well chronic cyanide toxicity (Wheeler et as elemental sulphur (Rosling, 1994). al., 1975) as sulphur was reported to The detoxification of HCN is therefore stimulate the rate of HCN detoxification influenced by the nutritional status of by rumen microbes (Promkot et al., the animal and B vitamins (B12, folic 2007). Injection of thiosulfate (which acid) and essential sulphur-containing makes sulphur available to the body) amino acids should be provided in the was found to detoxify HCN by diet in the form of good quality protein converting the poisonous HCN into (Bradbury & Holloway, 1998). Agency less toxic thiocyanate (FAO, 1990). A for Toxic Substances and Disease low protein diet deficient in sulphur- Registry (1997) reported that the major containing amino-acids may decrease 342 Utilization of cassava peels as feed for ruminants in Ghana

the HCN detoxification capacity and (methionine and cysteine) as well as thus makes the animal susceptible to elemental sulphur in diet will protect the toxic effect of cyanide (Oke, 1978). the animals from HCN toxicity. Dietary Therefore, HCN toxicity should sulphur was able to reduce HCN level not constitute a major limitation to at inclusion level of 0.25% and caused the use of cassava products and by- a body weight change of 83% and 68% products as livestock feed as simple at inclusion levels of 0.5% and 0.75% provision of sulphur in the form respectively (Table 5). of sulphur containing amino acids

Table 5: Effects of dietary sulphur level on growth performance and some metabolic indices of sheep and goats fed cassava/urea based diets Dietary sulphur (%) Parameters 0 0.25 0.50 0.75 HCN (mg/kg) 247.0 246.0 248.0 247.0 Body Weight Change (%) -75.0 -25.0 83.34 68.34

Ruminal NH3N (mg/100ml) 2.45 2.40 0.75 1.05 Ruminal thiocyanate 4.01 3.10 3.60 2.80 (mg/100ml) Serum Thiocyanate 0.035 0.073 0.060 0.073 (mg/100ml) Tewe (1992)

Effect of different methods al., 1977). Akinsoyinu (1992) combined of conservation on intake, dried cassava peels with poultry litter digestibility and growth as a nitrogen source and used this performance of ruminants formulation to replace maize in diets of Dried cassava peels and rice-straw goats at 0, 50, or 100%. No effect on fortified with urea as a dry season DM intake was noted across treatments. supplementary feed was fed to grazing However, digestibility reduced with sheep. It was observed that whereas increasing levels of replacements. In sheep supplemented with rice straw and other studies, substitution of maize cassava peel gained weight, sheep used cobs with cassava peels (20%) in sheep as control lost about 15% of their body fed pangola grass (Digitaria eriantha) weight during the dry season (Otchere et Utilization of cassava peels as feed for ruminants in Ghana 343

hay improved digestibility, body weight from 0.07 kg/d to 0.33 kg/d compared gain, and rumen function (Smith, 1988). to 0.29 kg/d for the dried peel (Larsen & Adebowale (1981) also fed fermented Amaning-Kwarteng, 1976). However, cassava peels to sheep at 0, 20, 40 Abate (1981) noted a decrease in the and 60% levels of inclusion to replace growth rate of beef calves offered a equivalent amounts of maize in the concentrate diet containing cassava control diet and observed ADG of 60, peels as the main source of energy. 38, 31 and 67 g/d and feed/gain ratios of Fomunyan & Maffeja (1987) in a study 7.8, 10.9, 11.8 and 7.4 kg feed/kg gain reported that sheep fed 0, 35 and 70% respectively. Formunyan & Meffeja cassava peel-based diets in addition to (1987) observed depressed ADG elephant grass and using cottonseed when fermented cassava peels were cake as the protein source gained 45, fed to sheep. They explained that such 106.7 and 227.1 g/d respectively. The depressed growth rates might be due conclusion was that live weight gains to the depressant effects of fermented of sheep increased with increasing cassava peels on rumen function. levels of cassava peels intake and that Whereas HCN may have adverse the peels showed promise as dry-season effects on animal growth, interpretation feed for sheep. Guimarães et al. (2014) of such data should always be done also recorded ADG of 154, 153 and with caution as they may be other 153g/d after supplementing lambs with confounding effects affecting animal 10, 20 and 30% dried cassava peels and growth performance. Whereas poor concluded that cassava peel could be performance of ruminants fed cassava included in the diet of sheep up to 30% products has often been attributed to with no change in intake and animal chronic toxicity other reasons such as performance. deficiency in dietary nitrogen could Karbo et al. (1997) reported be responsible for observed poor that supplementation of Sahelian and performance (Smith, 1992). Djallonké crosses with cassava peels Sheep fed a diet containing 80% improved ADG of sheep compared to ensiled cassava peels had higher daily supplementation with pigeon pea (130 gain of 81g/d as compared to those fed g/d vs. 87.9 g/d). Asaolu (1988) fed two sun-dried peels which gained 59 g/d groups of sheep with 80% each of dried (Heuzé et al., 2012). Supplementing or ensiled cassava peels supplemented with ensiled cassava peels increased in each case with 20% Gliricidia the ADG of grazing cross-bred cattle leaves. Sheep from both groups were 344 Utilization of cassava peels as feed for ruminants in Ghana

compared to a control group fed 100% used to improve the reproductive and Gliricidia. It was observed that sheep total productivity of sheep compared fed mainly Gliricidia performed better to sheep offered a control diet (Addah, than those on the cassava peel diets. 2005; Table 6). In that study, sheep However, DM intake, digestibility and offered cassava peels diets also had ADG of sheep fed the ensiled cassava lower mortality rates and higher pre- peel were superior to those fed the dried weaning growth rates but prolificacy cassava peel diet. rates were similar. Sun-dried cassava peels have been

Table 6: Effects of cassava peels on some reproductive performance of sheep in the Ashanti region. Birth Placental Pre – Pre – Prolificacy Total Item weight weight. weaning weaning Productivity (kg) (g) growth Mortality rate (g/d) (%)

Cassava 1.54 129 77.3 25 1.0 6.3 peels Control 1.18 99 30.4 75 1.0 0.72

Source: Addah (2005). Prolificacy rate: No. of lambs born alive/stillbirth per no. of ewes lambingPre-weaning lamb mortality: No. of lambs dying before weaning/no. of lambs born aliveTotal Productivity: Total no. of lambs weaned x mean weaning weight/ Total no. of ewes mated The supplementary diet contained 73% cassava peels and 27% whole cotton seed. The Control diet contained 81% and 19% Brachiaria decumbens and Gliricidia sepium respectively.

CONCLUSION and quality poses a major limitation Livestock production is an integral part to the success of smallholder livestock of the farming system of Ghana where production systems as livestock depend the economy is agriculture-based. mainly on natural-growing forages and Integration of arable crop cultivation left-over crop residues which decline and small ruminant production is a rapidly in quality and quantity during common practice among farmers in the the dry season. Agro-industrial by- country especially in rural Ghana where products and crop residues are available integrated crop-livestock farming is their in appreciable quantities and provide mainstay. However, feed availability opportunity to maximize livestock Utilization of cassava peels as feed for ruminants in Ghana 345

production as these feed resources are peels as ruminant feed are HCN and of less useful value as human food. tannins and low protein. Methods Ghana being the fourth largest producer such as drying, ensiling/fermentation, of cassava in Africa generates a lot of soaking as well as boiling have been cassava peels which can be used as found to be effective in reducing or animal feed. eliminating the cyanide in the peels. Of Most of these by-products are often these methods, ensiling has a combined however under-utilized by smallholder effect of reducing the cyanide content to farmers because of technical challenges tolerable levels as well as increasing the of how to conserve, store and improve crude protein content. Therefore, HCN their nutritional value. From the should not pose a limitation to the use of review of previous studies, cassava cassava peels as animal feed especially peels have been found to be used in the dry season. Supplementation as a main or supplementary feed by with protein-rich feedstuff like cotton smallholder ruminant farmers in rural, seed will help address the challenge of peri-urban and urban areas because it low protein content. is high in digestible energy. The major limitations to the utilization of cassava 346 Utilization of cassava peels as feed for ruminants in Ghana

REFERENCES

Abate, A. N. (1983). Digestibility of weaner beef calf supplements based on maize, cassava and millet. Animal Production Research Department annual report. Muguga, Kenya. pp. 56‒66. Adamafio, N. A., Sakyiamah, M. & Tettey, J. (2010). Fermentation in cassava (Manihot esculenta Crantz) pulp juice improves nutritive value of cassava peel. African Journal of Biochemistry Research, 4, 51–56. Addah, W. (2005). Reproductive response of confined West African dwarf sheep fed whole cotton seed and cassava peels during different trimesters of pregnancy. Thesis (MSc.), Kwame Nkrumah University of Science and Technology. pp. 95. Addah, W., Niayale, R. & Ayantunde, A. A. (2016). Effects of ensiling cassava peels on some fermentation characteristics and on growth performance of sheep on-farm. Paper presented at the Africa Research In Sustainable Intensification for the Next Generation (RISING) legacy project workshop. Bamako, Mali. December 12–13, 2016. p. 16. [Available at: AR_WA_phase_1_legacy_book_of_abstracts.pdf. Adebowale, E. A. (1981). The maize replacement value of fermented cassava peels (Manihot utilissima) in rations of sheep. Tropical Animal Production, 6, 54‒59. Agency for toxic substances and disease registry (1997). Toxicological profile for cyanide. Atlanta, Georgia, U.S.A. Ahamefule, F. O., Ibeawuchi, J. A. & Nwankwo, D. I. (2005). Utilization of sun-dried fermented and ensiled cassava peal meal-based diets by weaner rabbits. Nigerian Agricultural Journal, 36, 52–58. Akinsoyinu, A. O. (1992). Grain replacement value of cassava peels for growing goats. Bioresource Technology, 40, 143–147. Annor, S. Y. & Adongo, S. A. (1992). The effect of treatment of crop residues with urea on feed intake and live weight performance of West African dwarf sheep in the dry season. The role of women. In: W. Amanfor and E. B. M. Koney (eds.). Proceedings of the West African Commonwealth Association/Ghana veterinary Medical Association Conference, Accra International Conference Centre Ghana. September 7–12, 1992. pp. 143. Asaolu, V. O. (1988). Utilization of cassava peels and Gliricidia sepium in the diet of the West African Dwarf sheep. Thesis (MPhil.). Obafemi Awolowo University, Nigeria. Utilization of cassava peels as feed for ruminants in Ghana 347

Balagopalan, C., Padmaja, G., Nanda, S. & Morthy, S. (1988). Cassava in food, feed and industry. Boca Raton, Florida, CRC Press. pp. 190–194. Blakley, R .L. & Coop, I. E. (1949). The metabolism and toxicity of cyanide and cyanogenic glycosides in sheep. 11. Detoxification of hydrocyanic acid. New Zealand Journal of Science Technology, 31, 1–16. Bradbury, J. H. & Holloway, W. (1998). Anti-nutritional factors in root crops. In: Chemistry of tropical root crops: significance of nutrition and agriculture in the Pacific, Canberra ACIAR. p. 201. Cannon, E. P., Leung, P., Hawkins, A., Petrikovics, I., DeLoach, J.& Way, J. L. (1994). Antagonism of cyanide intoxication with murine carrier erythrocytes containing bovine rhodanase and sodium thiosulphate. Journal of Toxicology and Environmental Health, 41, 267–274. Clerk, G. C., & Caurie, M. (1968). Biochemical changes caused by some Aspergillus spp. in root tubers of cassava (Manihot esculenta Crants). Tropical Science, 10, 149–154. Conn, E. E. (1994). Cyanogenesis‒ a personal perspective. In: Bokanga, M., Essers, A. J. A., Poulter, N., Rosling, H. and Tewe, O. (eds.). Proceedings of the international workshop on cassava safety. March 1‒4th, 1994, Ibadan, Nigeria.Cooke, R. D., & Maduagwu, E. N. (1985). The effect of simple processing on the cyanide content of cassava chips. Journal of Food Technology, 13, 299–306. Enneking, D., & Wink, M. (2000). Towards the elimination of anti-nutritional factors in grain legumes. In: Knight, R. (ed.), Linking research and marketing opportunities for pulses in the 21st century: Proceedings of the third international food legumes research conference, held in Adelaide, South Australia, 22–26 September 1997. Dordrecht, the Netherlands: Kluwer Academic Publishers. pp. 671–683. FAO. (2013). FAOSTAT data. Food and Agriculture Organization, Rome. Fomunyan, R. T., & Meffeja, F. (1987). Cassava by-produces in rabbit and sheep diets. In: Utilization of Agricultural by-products as livestock feeds in Africa. Little, D.A. and Said, A.N. (eds.), ILCA, Addis Ababa. pp. 103‒107. Food and Agriculture Organization (1990). In: Roots, tubers, plantains and bananas in human nutrition. Toxic substances and anti-nutritional factors. Rome. Available online at: http://www.fao.org/docrep/t0207e/T0207E00.htm. Gomez, G. & Valdivieso, M. (1988). The effects of ensiling whole root chips on cyanide elimination. Nutrition Report International, 37, 1161–1166. Gomez, G., Valdivieso, M., De la Cuesta, D., & Salcedo, T. S. (1984). Effect of variety and plant age on the cyanide content of whole root cassava chips and its reduction by sun drying. Animal Feed Science and Technology, 11, 57–65. Gomez, G., Valdivieso, M., de la Cuesta, L. A. D., & Kawano, K. (1984). Cyanide 348 Utilization of cassava peels as feed for ruminants in Ghana

content in whole-root chips of ten cassava cultivars and its reduction by oven drying or sun drying on trays. Journal of Food Technology, 19, 97–102. Guimarães, G. S., Ferreira da Silva, F., Lemos da Silva, L., Galvão, L. M. G., Machado dos Santos, L., & Alencar, A. M. (2014). Intake, Digestibility and Performance of Lambs Fed with Diets Containing Cassava Peels. Ciênc. Agrotec. Lavras, 38, 295‒302. Heuzé, V., Tran G., Bastianelli, D., Archimède H., Lebas, F., & Régnier, C. (2012). Cassava tubers. Feedipedia.org. A programme by INRA, CIRAD, AFZ and FAO. http://www.feedipedia.org/node/527 Ifut, O. J. (1992). The potential of cassava peels for feeding goats in Nigeria. Cassava as livestock feed in Africa. In: S. K., Hahn, L. Reynolds, and G. N Egbunike, (Eds.). Proceedings of the IITA/ILCA/University of Ibadan workshop on the potential utilization of cassava as animal feed in Africa. Ibadan, Nigeria, pp. 72-84. Jian, G., Cuijun, Y., & Guihe, L. (2015). Analysis to wilting and mixed silage effect on naked oats (Avena nuda) and alfalfa (Medicago sativa). International Journal of Agricultural Biology, 17, 761–766. Jianxin, L. (2002). Ensiling crop residues. In: Guo Tingshuang, Manuel D. Sanchez and Guo Pei Yu. Animal production based on crop residues Chinese experiences. Food and Agriculture Organization of the United Nations. May, 2002. pp. 82–-103. Karbo, N., Alhassan, W. S., Adongo, S. A., & Bruce, J. (1997). Small holder lamb fattening based on crop residue and agro-industrial by-products in Northern Ghana. Proceedings of the twenty-second Ghana Animal Science Association Symposium. pp. 103‒ 108. Konlan, S. P. Ayantunde, A. A., Addah, W., Dei, H. K., & Karbo, N. (2016). Emerging feed markets for ruminant production in Northern Ghana. In: Proceeding of the Animal Science Association. I. I. Abdul-Rahman, T. Ansah, Addah, W. and B. Acquah (eds.). International Conference Centre, UDS, Tamale. August 3-6th, 2016. pp. 322-336. Larsen, R. E. & Amaning-Kwarteng, K. (1976). Cassava peels with urea and molasses as dry season supplementary feed for cattle. Ghana Journal of Agricultural Science. 9:43‒47. Lukuyu, B., Okike, I., Duncan, A., Beveridge, M., & Blümmel, M. (2014). Use of cassava in livestock and aquaculture feeding programs. ILRI. Nairobi, Kenya. International Livestock Research Institute. Discussion Paper 25. Maner, J. H. & Gomez, G. (1973). Implications of cyanide toxicity in animal feeding studies using high cassava rations in chronic cassava toxicity: Proceedings of an interdisciplinary workshop, London, England, 29 – 30 January 1973. IDRC. pp. 113 –120. Utilization of cassava peels as feed for ruminants in Ghana 349

Meneses, M. D., Megias J., Madrid, A., Martinez‒Teruel, F., Hernandez, J., & Oliva, J. (2007). Evaluation of the phytosanitary, fermentative and nutritive characteristics of the silage made from crude artichoke (Cynara scolymus L.) by‒ product feeding for ruminants. Small Ruminant Research, 70, 292‒296. Nambisan, B., & Sundaresan, S. (1985). Effects of processing on the cyanogenic glycoside content of cassava. Journal of Science, Food and Agriculture, 36, 1197–1203. Oboh, G. (2002). Nutritional, toxicological and by-products utilization potentials of micro-fungi fermented cassava (Manihot esculenta, Crantz) tuber roots. Akure, Federal University of Technology, Thesis (PhD). Okafor, N. (1998). An integrated bio-system for the disposal of cassava wastes. Integrated bio-systems in zero emissions applications: Proceedings of the internet conference on integrated bio-systems. Oke, O. L. (1978). Problems in the use of cassava in animal feeding. Animal Food Science Technology, 3, 345‒380. Onua, E. C., & Okeke, G. C. (1999). Replacement value of processed cassava peel for maize silage in cattle diet. Journal of Sustainable Agriculture and the Environment, 1, 38‒43. Onyimonyi, A. E., & Ugwu, S. O. C. (2007). Bioeconomic indices of broiler chicks fed varying ratios of cassava peel/bovine blood, International Journal of Poultry Science, 6, 318–321. Oppong-Anane, K. (2013). Cassava as animal feed in Ghana: Past, present and future. B. Bedane, C. Ly and H.P.S. Makkar (eds.). FAO, Accra, Ghana. pp. 44. Osuntokun, B. O. (1981). Cassava diet, chronic cyanide intoxication and neuropathy in Nigerian Africans. World Review. pp. 141–173. Otchere, E. O., Dadzie, C. B. M., Erbynn, K. G., & Ayebo, D. A. (1977). Response of sheep to rice straw or cassava peels fortified with urea and molasses as supplemental feeds to grazing. Ghana Journal of Agricultural Science, 10, 61 ‒66. Phuc, B. H. N., Ogle, R. B., Lindberg, J. E., & Preston, T. R. (1996). The nutritive value of sun-dried and ensiled cassava leaves for growing pigs. Livestock Research for Rural Development. Volume 8, Article #30. Retrieved December 21, 2016, from: http://www.lrrd.org/lrrd8/3/phuc83.htm Promkot, C., Wanapat, M., & Rowlinson, P. (2007). Estimation of ruminal degradation and intestinal digestion of tropical protein resources using the nylon bag technique and the three step in vitro procedure in dairy cattle on rice straw diets. Asian-Australian Journal of animal science, 20, 1849–1857. Rosling, H. (1994). Measuring effects in humans of dietary cyanide exposure from cassava. Acta Horticulture, 375, 271–283. 350 Utilization of cassava peels as feed for ruminants in Ghana

Shoremi, O. I. A., Ayoade, J. A., & Akinwale, V. O. (1999). Maize replacement value of cassava peels soaked in water for different time periods in grower rabbit ration. Journal of Applied Animal Research, 15, 87‒91. Smith, O. B. (1992). A review of Ruminant Responses to cassava based diets. Cassava as Livestock feed in Africa Proceedings: IITA/ILCA/University of Ibadan, Workshop on the Potential Utilization of Cassava as Livestock Feed in Africa. pp. 39‒53. Smith, O. B. (1988). A review of ruminants’ responses to cassava based diets. In: cassava as livestock feed in Africa Proc. ILRI/ILCA University of Ibadan. Workshop on potential utilization cassava as Livestock feed in Africa. pp. 39‒53. Sogunle, O. M., Fanimo, A. O., Abiola, S. S., & Bamgbose, A. M. (2009). Performance of growing pullets fed cassava peel meal diet supplemented with cashew nut reject meal, Archives Zoo technology, 58, 23–31. Sorbo, B. (1962). Enzymatic conversion of cyanide to thiocyanate, Metabolic factors controlling duration of drug action. B. B. Brodie, and E. G. Evdolds (eds.). pp. 121–128. Tewe, O. O. (1983). Thyroid cassava toxicity in animals. In: Cassava toxicity and thyroid: Research and public health issues. Delange, F. and Ahluwalio, R. (eds.). Ottawa, Canada. IDRC. pp. 114–118. Tewe, O. O. (1992). Detoxification of cassava products and effects of residual toxins on consuming animals. In. Roots, tubers, plantains and bananas in animal feeding. Proceedings of the FAO Expert Consultation held in CIAT, Cali, Colombia 21–25 January 1991. Machin, D. and Nyvold, S. (eds.). FAO Animal Production and Health Paper 95. Tewe, O. O., & Iyayi, E. A. (1989). Cyanogenic glycosides. In: Cheeke, P.R. (ed.). Toxicants of plant origin, Glycosides. CRS Press. 2, 43–60. Tewe, O. O., & Kasali, O. B. (1986). Effect of cassava peel processing on the performance, nutrient utilization and physiopathology of the African giant rat (Cricetomys gambianus). Tropical Agriculture, 63, 125–128. Tweyongyere, R., & Katongole, I. (2002). Cyanogenic potential of cassava peels and their detoxification for utilization as livestock feed. Veterinary and Human Toxicology, 4, 366–369. Westby, A., & Choo, B. K. (1994). Cyanogen reduction during lactic fermentation of cassava. In: Bokanga, M., Essers, A. J. A., Poulter, N., Rosling, H. and Tewe, O. (eds.). Proceedings of the international workshop on cassava safety, March 1‒4, 1994, Ibadan, Nigeria, Acta Horticulturae, 375, 209‒215. Wheeler, J. L., Hedges, D. A., & Till, A. R. (1975). A possible effect of cyanogenic glucoside in sorghum on animal requirements for sulphur. Journal of Agricultural Science, 84, 377‒379 Product development from Yam in West Africa 351

Product development from Yam in West Africa: market potential and challenges

Michael A. Boateng1,2, Faustina D. Wireko-Manu2, Jacob K. Agbenorhevi2 and Francis O. Amoako-Andoh1 1Council for Scientific and Industrial Research-Crops Research Institute, Kumasi, Ghana 2Department of Food Science and Technology, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana

Abstract value chain particularly processing and Yam (Discorea spp.) is one of the most product development are discussed. It is important food crops contributing to envisaged that the optimal potential of food security in West Africa. About 91% yam as source of food and value–added of the world’s yam production comes products can be achieved if research from West Africa. However, 20-30% of and development measures identified yam is estimated to be wasted annually are efficiently engaged for enhanced due to poor postharvest management. outputs and economic gains. The market value of yam tubers decreases when in season, but the price Introduction rises to over 200% during the growing Over 300 million people in West Africa, season, making it unaffordable to most Asia, and the Caribbean depend on yam consumers, especially when compared (Dioscorea spp.) as an economically to substitutes such as cassava and important staple food. Ninety-six maize. Yam is a valuable commodity percent (96%) of the worlds yam is for its nutritional and starch contents, produced by Africa, with Nigeria, which play key functionality in various Ghana, Côte dIvoire, Bénin, and Togo food and non-food applications. In this as the top five producers, in that order. chapter, some of the new food products Nigeria alone produced over 45.0 developed from yam in West Africa million tonnes of yam, representing are reviewed. The market potential sixty six percent (66%) of the worlds as well as challenges facing the yam total production volume (68.1 million 352 Product development from Yam in West Africa

MT) in 2014 (FAOSTAT, 2016). Yam is a (“yellow yam”) to be in the same species better source of protein and nutritionally as D. rotundata, and like D. alata, superior to other staple root and tuber D. cayensis is used to make pounded crops (Otoo & Asiedu, 2009). In West yam products in Africa (Kay, 1987). Africa, the most frequently cultivated Less frequently cultivated species than species are D. rotundata (“white the above-mentioned species are D. yam”) and D. alata (“water yam”) opposita (“Chinese yam”), D. trifida (IITA., 2009), nonetheless Dioscorea (“Cush-Cush yam”), D. bulbifera (“air spp. consist of an extensive range of potato”), and D. dumentorum (“bitter vegetatively propagated tuber species, yam”) (Kafilat, 2010). Some yams are both diploids and polyploids. Largely, grown only for medicinal purposes, and taxonomists consider D. cayensis others for edible purposes (IITA, 2008).

Picture 1: White Yam Picture 2: Yellow Yam

Picture 3: Water yam Picture 4: Bitter yam Product development from Yam in West Africa 353

Picture 5: Chinese yam Picture 6: Air potato Yam tubers are a highly perishable developing products out of it. commodity requiring much attention Product development is a systematic, due to pest infestation and physiological commercially-oriented research deterioration as a result of its high to develop products and processes moisture content (50-80%) and high satisfying a known or suspected respiration rates (Noamesi, 2008). consumer need (Winger & Wall, 2006). According to Anoma & Thamilni It is a combination and application (2016), yam tubers like other roots and of natural sciences with the social tuber crops are bulky in nature with sciences (food science and processing high moisture content thereby attracting with marketing and consumer science) high transportation cost. Additionally, into one type of integrated research, yam tubers have a short shelf life with whose aim is the development of new limited market margin in developing products (Winger & Wall, 2006). Yam countries where they are mainly product development is an aspect cultivated. Lasisi (2009) asserts that of value addition. Adding value to due to the high degree of perishability, yam tubers involve developing good bulkiness and distance from production quality varieties for local and industrial area to the consuming centers as well products, developing new products and as the seasonal nature of production, adopting suitable marketing strategies attention should be given to processing for old and new products. of the tubers. Akingbala et al. (1995) Research has revealed that the level emphasized that a certain amount of of yam processing in West Africa is processing goes into most of the foods relatively low compared to substitute sold in the market, and yam also needs crops such as cassava (Sahel Capital to be processed for consumption by Limited, 2014). This is linked to a range 354 Product development from Yam in West Africa

of barriers. A collaborative approach chips or roasted. It is often served as towards addressing the barriers to yam yam balls when mashed during festivals processing will transform the yam (Afoakwa & Sefa-Dedeh, 2001). In value chain, thereby improving the Nigeria, yam is usually processed into incomes and livelihoods of thousands dry yam tubers/slices called “gbodo” of farmers, reducing post-harvest in Yoruba land by peeling, slicing, losses and enhancing the availability parboiling in hot water, soaking, and and affordability of yam products sun-dried (Onayemi & Potter, 1974). through the release of innovative new Gbodo, a traditionally processed dry products (Sahel Capital Limited, 2014). yam gives an intermediate flour product The need to enhancing food security upon milling called “elubo.” Elubo is with yam cannot be overemphasized, usually stirred in boiling water to obtain especially processing the tubers into a paste called “amala” which is usually forms that can enhance longer storage eaten with soups (Akissoe et al., 2000; for use during the hunger or off-season Ayodele, et al., 2013; Kordylas, 1990). periods of most tropical crops Yam is also consumed as dry- slices and as flour in Nigeria, Ghana Food products from yam and Bénin, although not as widely as In the humid tropical countries of West products with the fresh form (Kafilat, Africa, yam is one of the most highly 2010). Yam flour can be referred to regarded food products and it is closely as “kokonte” (Bricas et al., 1997) integrated into the social, cultural, or elubo (Kafilat, 2010). Consumers economic and religious aspects of life often consider products prepared from (Ackah et al., 2014). The traditional yam flour an inferior substitute for uses of yam, though diverse, are freshly pounded yam because flour mainly for food, aimed at providing may typically be made from damaged relatively cheaper source of calories to yam tubers. Nonetheless, early studies its consumers. As food, yam is prepared by FAO reported no difference in in various forms across West Africa. In nutritional value (FAO, 1993). In Ghana, yam is normally consumed by Ghana, especially in the Northern boiling and pounding into a dough-like region, yam flour is used to prepare consistency called “fufu”, and then eaten two local dishes, Gabli and Wasawasa, with a soup (Obadina et al., 2007). Yam which are not widely consumed and is also consumed by boiling and eating therefore not popular (Yam Sector as boiled slices (ampesi), fried as yam Development Strategy, Ghana, 2013). Product development from Yam in West Africa 355

Picture 7: Yam fufu with soup Picture 11: Roasted yam with stew

Picture 8: Boiled yam with stew

Picture 12: Amala

Picture 9: Fried yam slices Picture 13: Gbodo

Picture 10: Yam balls Picture 14: Elubo 356 Product development from Yam in West Africa

Yam is used in other parts of the world produce spirits and beer in Japan (Yam like Japan, in the production of several foods such as instant noodles, instant soups, pastas, high quality yam flour, Sector Development Strategy, Ghana, and natural colored yam powder. In some regions including the Pacific Islands, Caribbean and Southeast Asia, 2013) yam flour or tubers are used in yam fruit cake, cupcake, ice cream or desserts. The beverage industry also uses yam to

Picture 15: Instant yam noodle Nowadays, several drugs are produced with yam as an ingredient for both allopathic and homeopathic medicine and also as nutraceutic products (Yam Sector Development Strategy, Ghana, 2013). Wild yam (Dioscorea villosa) is often promoted as a “natural Picture 16: Yam fruit Cake alterative” to estrogen therapy. It is used for estrogen replacement therapy, vaginal dryness in older women, PMS (premenstrual syndrome), menstrual cramps, weak bones (osteoporosis), increasing energy and sexual drive in men and women, and breast enlargement (Park et al., 2009). Wild yam is Picture 17: Purple yam powder also used for treating a disorder of the intestines called diverticulosis, Non-food products from yam gallbladder pain, rheumatoid arthritis, Yam is also processed into non-food and for increasing energy (Iwata et al., products. Some yam species are a 2009; Kong et al., 2009). Some women source of dioscin, which is an active apply wild yam creams to the skin to ingredient of birth control pills. reduce menopausal symptoms such Product development from Yam in West Africa 357

as hot flashes (Komesaroffet al., 2001). radical scavenging activity (Hou et al., 2001) and showed beneficial effects in lowering blood pressure (Hsu et al., 2002; Iwu et al., 1990). In addition, dioscorin demonstrated angiotensin converting enzyme (ACE) inhibitory and antihypertensive activities on spontaneously hypertensive rats (Hsu et al., 2002). The dioscorin from yam exhibited carbonic anhydrase, trypsin Health benefits of yams inhibitor dehydroascorbate reductase Yam is estimated to provide more than (DHA), and monodehydroascorbate 200 dietary calories each day for over reductase (MDA) activities and 60 million people in West and Central immunomodulatory activities (Hou Africa (FAO, 2002). Its crunchy edible et al., 1999, Hou et al., 2000; Martin, tuber chiefly composed of complex 1974). Cornago et al., (2011) showed carbohydrates and soluble dietary fiber that two major Philippine yams, Ube (Woolfe, 1987). Dietary fiber help (purple yam) and Tugui (lesser yam) reduce constipation as well as decrease contain considerable phenolic content bad cholesterol levels by binding to it that exhibited significant antioxidant in the intestines and lower colon cancer activities against free radicals. Purple risk by preventing toxic compounds in yam (Dioscorea alata) and lesser yam the food from adhering to the colon (Dioscorea esculenta) had TPC values mucosa. Additionally, being a good ranging from 69.9 to 421.8mg Gallic source of complex carbohydrate, it Acid Equivallent (GAE)/100g dry regulates steady rise in blood sugar weight. The purple yam variety Daking levels. For the same reason, yam is had the highest TPC and antioxidant recommended as low glycemic index activity values as measured by DPPH healthy food. According to Lasisi radical scavenging activity, reducing (2009), yam flour meals give more power and ferrous ion chelating sustainable energy and better protection capacity, whereas varieties Sampero against obesity and diabetes. and Kimabajo exhibited the lowest Dioscorin from fresh yam corresponding values. (Dioscorea batatas) exhibited DPPH Yam tubers are an excellent (2, 2-diphenyl-1-picrylhydrazyl) source of the B vitamins, providing 358 Product development from Yam in West Africa

adequate daily requirements of as a co-factor for the antioxidant pyridoxine (vitamin B6), thiamin enzyme, superoxide dismutase. Iron is (vitamin B1), riboflavin (vitamin B2), required for red blood cell formation. folates (vitamin B9), pantothenic acid Yam processing (vitamin B5) and niacin (vitamin B3) The yam processing sector is currently (Barquar & Oke, 1977). These vitamins underdeveloped. Processing is mainly mediate various metabolic functions limited to production of the yam flour, in the body. The fresh yam tuber also which is on demand for the outside contains good amounts of vitamin-C market for the preparation of traditional (29% of recommended levels per meals. The importance of processing 100 g) (Bradbury & Singh, 1986), an in the yam industry is very crucial for antioxidant, playing such important agribusiness and a sure way to empower roles in anti-aging, immune function the society economically, especially booster, wound healing, and bone women as there is a growing need growth. Yams, especially the yellow for off-farm cash generating activities flesh types, may contain small amounts (Yam Sector Development Strategy, of provitamin A carotenoids (Osagie, Ghana, 2013). 1992). Vitamin A has many functions According to Ackah et al. (2014), including maintaining healthy mucus the possibility of processing yam, membranes and skin, night vision, especially less preferred yam varieties growth and protection from lung and like water and yellow yams, into other oral cavity cancers (Ross, 2010). forms like chips, flour, wasawasa and Further, the tuber is indeed industrial starch should be explored by one of the good sources of minerals research, private business initiatives such as copper, calcium, potassium, and non-governmental organizations iron, manganese, and phosphorus. that are interested in food security at the Hundred grams of yam provides household level. Yam processing will not about 816 mg of potassium (Osagie, only reduce the quantum of yam losses 1992). Potassium is an important every year during the harvest season, component of cell and body fluids, and but it will also ensure the continuous helps to control heart rate and blood supply of yam products throughout the pressure by countering hypertensive year to facilitate reduction of the price effects of sodium. Copper is required differential between harvest and lean in the production of red blood cells. seasons. This would therefore, make Manganese is used by the body Product development from Yam in West Africa 359

yam more accessible to low-income in 500-gram portions in air-tight plastics households, especially during the lean and then enclosed in attractive cartons season. either for sale in the local supermarkets Studies have recently shown that or for export. Preservation of fresh yam D. alata has higher yields, better storage in brine has also been attempted, but capacities, and higher nutritional value with little success (http://www.food- in comparison with D. rotundata (Baah info.net/uk/products/rt/yam.htm, n.d.). et al., 2009; Wireko-Manu et al., Source:https://www.google.com. 2014). The findings have generated gh/search recommendations amongst nutritionists Food Research Institute of the and crop scientists to intensify and Council for Scientific and Industrial diversify food uses of D. alata in Sub- Research (FRI-CSIR) of Ghana has Saharan Africa. Wireko-Manu et al., developed fufu flour for the market (2014) state that the need “to enhance (http://www.foodresearchgh.org/ the food security (of D. alata) cannot be our-products). The institute recently overemphasized, especially processing out-doored three new products made it into forms that can enhance longer from yam (http://edition.myjoyonline. storage for use during the hunger or off com). The products are yam flour, seasons of most tropical crops”. Ajibola yam crisp and precooked vacuum et al, (1988) indicated that D. alata is packaged yam. The yam flour comes frequently preferred for food uses such with legumes and soya blends, which as porridge. Consequently, Wireko- could be used for puddings as well Manu et al. (2014) concluded that to as pastry while the yam crisp can be increase production, market value and consumed as a snack. The precooked diversity of the food uses of water yam vacuum packaged yam is partly cooked (D. alata), specific varieties should be and frozen to cut down on the length promoted for products such as amala, of time it takes to cook. The products, where they may have comparative according to the manufacturers, advantage over D. rotundata (Wireko- should make it more convenient for Manu et al., 2014). restaurants and households that wish to In recent times, small-scale use yam in their menus (http://edition. factories have been set up to process myjoyonline.com). dried yam chips into fufu powder (Yam The Department of Food Science Sector Development Strategy, Ghana, and Technology of the Kwame 2013). Powdered dry yam is packaged Nkrumah University of Science and 360 Product development from Yam in West Africa

Technology also recently developed from D. rotundata in terms of color and introduced a number of novel and texture on a 9-point categorical yam-based products. These products scale that included color, smoothness, are yammy pops (extruded yam- consistency, elasticity, stickiness and tamarind-baobab snack), yam-minced hardness. D. alata demonstrated greater beef, yam pasta, yam couscous and suitability for amala, which according yam-tigernut pudding. The Project, to the authors could be attributed to KNUST-CRI Improved Yam Storage the high gel strength of its flour and for Food Security and Income under the the parboiling of tubers before drying, sponsorship of AUSAID Development which collectively increase pasting Research Awards (ADRA) organized properties. These attributes accordingly community training on diversified characterized the relatively intense yam-based food products in August, browning observed during cooking 2015. The participants were taught (Wireko-Manu et al., 2014). how to make high-quality yam Ekwu et al., (2005) conducted flour for all flour-based products a descriptive sensory evaluation and in combination with wheat flour, sensory analysis on flours made from amala flour, soup thickener as well as three African varieties of white yam substituted yam flour in local products (D. rotundata) locally referred to as including koose, wasawasa, tubani, Ozibo, Okpebe, and Nwopoke for noodles yakeyake (http://foodscience. texture, stickiness, appearance, and knust.edu.gh/news) general acceptability. The results indicated that color, texture, and general Consumer preferences acceptability of Okepebe and Nwopoke Wireko-Manu et al. (2014) were statistically similar, while these systematically compared D. alata varieties significantly differed from and D. rotundata using a multiple Ozibo. Nwopoke was preferred by the comparison sensory test adapted from consumer panel to make flour (fufu), Meligaard et al., (1999) for pasty yam followed by Okpebe. The authors products. The test requires that trained concluded that whereas Okpebe has sensory evaluators compare each good fufu making qualities, traditional variety to a reference sample using a yam fufu producers generally use categorical scale. The authors found Nwopoke because of the difficulty that D. alata varieties were either in pounding Okpebe which has high better than or not significantly different stretchability potentials (Ekwu et al., Product development from Yam in West Africa 361

2005). for old and new products. In this Nindjin et al. (2007) found respect, IITA is undertaking a research that a panel of adult villagers in Côte to present a set of improved varieties d’Ivoire preferred fufu (“foutou”) of water yam (Dioscorea Alata), white made from D. cayenensis-rotundata yam (Dioscorea Rotundata), trifoliate for textural attributes, whereas they yam (Dioscorea Dumetorum), and disliked “foutou” made from D. alata. yellow yam (Dioscorea Cayenensis) The authors reported that “easiness to for evaluation in industrial processes mould” and springiness were among and products that use yam flour as a the most desirable characteristics component (Yam Sector Development for pounded yam products, and that Strategy, Ghana, 2013). According lumpiness contributed to the dislike of a to Palaniswami & Peter (2008), particular yam cultivar. Otoo & Asiedu agricultural potential is greatest for (2009) conducted a consumer sensory root and tuber crop like yam due to their evaluation of 36 yam genotypes over adaptability to marginal environments, a three-year period and disaggregated their contribution to household food their results by gender, occupation security, and their flexibility in mixed and agroecology. They observed that cropping systems. agroecology had no significant effect on The bakery industry could be one yam preferences for farmers, but there of the biggest beneficiaries of yam flour. were gender differences in preferences Yam flour is gluten-free. It gives special for texture and taste. Farmers in the taste to the products by making them study considered taste, texture, color soft as the conventional wheat flour attractiveness, aroma and aftertaste to bakery products. For industrial uses, be important determinants of overall yam also has a great potential as a food acceptability (Otoo & Asiedu, 2009). ingredient and also as edible plastic films The potential of yam-based protecting foods in the supermarkets products (Yam Sector Development Strategy, Value addition is one of the Ghana, 2013). main milestones of yam product Apart from food industry development. Adding value to the application, starch obtained from crop means developing good quality yam can be used in the textile, paper, varieties for local and industrial adhesive, ethanol, biodegradable products, developing new products, and plastics and other non-food markets. adopting suitable marketing strategies Yam starch has unique properties 362 Product development from Yam in West Africa

because of its similarity to both potato dismutase (Chan et al., 2010). These and rice starches combined. Yam findings suggest that phytochemicals starch can easily find a place in the of yams seem to enhance activities of global industrial market for different endogenous antioxidant enzymes. applications, even by using a small Wang et al., (2011) reported that percentage to add to other group of aqueous extracts of yam (Dioscorea

ingredients (Yam Sector Development alata) inhibited H2O2-CuSO4 induced Strategy, Ghana, 2013). damage of calf thymus DNA and Potential health benefits of yam also protected human lymphoblastoid

Yam tubers contain a variety of cells from CuSO4 induced DNA bioactive components, including mucin, damage. Water yam extracts contain a dioscin, dioscorin, allantoin, choline, homogenous compound with a single polyphenols, diosgenin, and vitamins copper-binding site (Wang et al., 2011). such as carotenoids and tocopherols The extract is also a good natural, safe (Bhandari et al., 2003; Iwu et al., 1990). (redox inactive) copper chelator (Wang Mucilage of yam tubers contains soluble et al., 2011). In addition to phenolic glycoprotein and dietary fibre. Several compounds, saponins and mucilage studies have shown that yam extracts polysaccharides present in yams are have hypoglycemic, antimicrobial and indicated to be also responsible for antioxidant activities (Chan et al., 2004; this activity. Furthermore, water- Kelmanson et al., 2000). Yams may soluble mucilage polysaccharides are stimulate the proliferation of gastric the most important copper chelators in epithelial cells and enhance digestive water yam extracts. Thus, Dioscorea enzyme activities in the small intestine alata aqueous extracts could serve as (Chen et al, 2003). potential agents in the management of The administration of yams copper-mediated oxidative disorders decreased the levels of – glutamyl and diabetes (Wang et al., 2011). transpeptidase (GGT), low density Yam dioscorin exhibited 훾 lipoprotein, and triacylglycerol in immunomodulatory activities by the serum of rats in which hepatic fibrosis innate immunity, a nonspecific immune was induced by carbon tetrachloride system which comprises the cells and (Chan et al., 2010). Treatment of rats mechanisms that defend the host with yams increased the antioxidant from infection by other organisms in activities of hepatic enzymes, namely, a nonspecific manner. Dioscorin was glutathione peroxidase and superoxide reported to stimulate cytokine production Product development from Yam in West Africa 363

and enhance phagocytosis(Liu et (2011 postulated that the highmolecular- al, 2007). Furthermore, the released weight polysaccharides in DsCE-II act cytokines may act synergistically with on specific target cell types in the GI phytohemagglutinin (PHA), a lectin tract, including dendritic cells, intestinal found in plants that stimulate the epithelial cells and T-cells, to mediate a proliferation of splenocytes (Martin, cascade of immunoregulatory activities, 1974). resulting in the recovery of damaged In vitro cytotoxic activity of cell populations following 5-FU or mouse splenocyte against leukemia cell other chemical-induced injuries to the was increased in the presence of YMP of bone marrow, spleen, or other immune Dioscorea batatas at 10 g/mL (Choi et cell systems (Su et al., 2011). al., 2004). Furthermore, the production Mucilage from Taiwanese 휇 of IFN- was significantly increased yams (Dioscorea alata) significantly in the YMP treated splenocytes, enhanced the innate and adaptive 훾 suggesting their capability of inducing immunity of laboratory bred strain of cell-mediated immune responses. In albino mice (BALB/c mice) through addition, YMP at a concentration of 50 oral administration (Shang et al., 2007). g/mL increased the uptaking capacity In addition, it was found that the specific and lysosomal phosphatase activity of antibodies rapidly responded against 휇 peritoneal macrophages (Choi et al, foreign proteins (antigens) introduced 2004). into the mice when the rodents were Dioscorea phytocompounds fed with yam mucilage. Mucilage enhanced murine splenocyte from these yam varieties exhibited proliferation ex vivo and improved a stimulatory effect on phagocytic regeneration of bone marrow cells in activity by mice macrophages (Shang vivo (Su et al., 2011). Mice fed with et al., 2007). a Dioscorea extract recovered from Yam (Dioscorea esculenta) damaged bone marrow progenitor cell showed anti-inflammatory activity on populations that had been depleted by carrageenan induced oedema in Wistar large doses of 5-fluorouracil (5-FU). rats paws (Olayemi & Ajaiyeoba, 2007). It was additionally reported that the However, this activity was removed phytocompound(s) responsible for from the system within 2 hours after these bioactivities had a high molecular reaching the peak. Phytochemical weight (≥100 kDa), and thus were most screening of D. esculenta confirmed likely polysaccharide in nature. Su et al. the presence of saponins, -sitosterol,

훽 364 Product development from Yam in West Africa

stigmasterol, cardiac glycosides, fats, Eastern, and Greater Accra regions of starch and diosgenin (Olayemi & Ghana. Ajaiyeoba, 2007). It was suggested Findings from the field research that diosgenin could be responsible revealed that the level of yam for the observed activity (Olayemi & processing in Nigeria and Ghana is Ajaiyeoba, 2007). Diosgenin contained relatively low compared to substitute in Chinese yam has recently been crops such as cassava. The results were demonstrated to be an immunoactive attributed to a range of reasons, which steroidal saponin which also showed were common to both countries. The prebiotic effect (Huang et al., 2012). key challenges to processing include: Diosgenin additionally had beneficial (1) high cost of yam, especially the growth effects on enteric lactic acid white yam variety used for processing bacteria (Huang et al., 2012). yam flour, (2) fragmented value chain which limits linkages between farmers The challenges of yam and processors, (3) high cost of quality product development yam processing equipment and power Sahel Capital was engaged by the generation, (4) cumbersome regulatory Bill & Melinda Gates Foundation in requirements for certification and December, 2013 to conduct a study on product registration, (5) lack of access to the landscape for yam value addition affordable financing, and (6) difficulties opportunities in Nigeria and Ghana, associated with building a distribution with a focus on processing for food. network. However, lack of consumer Activities of the study included conduct awareness and inconsistent demand of interviews with key stakeholders for processed yam products were in the agricultural research institutes, two additional challenges that were private sector (including equipment identified in the Ghanaian landscape fabricators, processors, transporters, (Sahel Capital Limited, 2014). wholesalers, retailers and farmers’ Peeling, which is removal of the clusters and associations), NGOs, outer layer of the yam tuber, is one of regulatory agencies, and state and the major problems of yam processing national ministries. In-depth field visits for both small and large scale bases due were also conducted in the priority to the irregular shape of yam tubers states including Oyo, Niger, Abuja, (Ayodeji et al., 2014). The need for an Ebonyi, Enugu and Lagos in Nigeria, effective method for the peeling and as well as the Brong Ahafo, Northern, slicing of yam tubers needs serious Product development from Yam in West Africa 365

attention. Developing yam peeling and sectors attended the meeting. slicing machine provides appropriate Feedback from the stakeholders technology since the traditional method highlighted that improvements in yam is tedious, raises hygiene concerns processing in West Africa requires and has high risk of injury. However, collaborative interventions from yam peeling remains a challenge to the government, private sector, the engineers involved in the design of yam research community and development processing machines (Adejumo, 2007; organizations. Interventions Aderoba, 2008; Adetan et al., 2006; recommended by the stake-holders Ukatu, 2002). The slimy nature of yam included the following: 1) the recognition tubers likewise poses a challenge to of yam as a priority crop and the need to starch extraction compared to root and develop an integrated strategic plans for tuber crop like cassava, even though strengthening the yam value chains., 2) yam contains comparatively more (60– investment in market-driven research 82%) starch (Baah et al., 2009; Gallant on high quality yam varieties that are et al., 1982). most suitable for processing and new product innovation, 3) development Improving Yam Processing of a unique registration window for On February 18, 2014, Sahel yam processors, to streamline and Capital organized a meeting on expedite the registration process, and yam improvement for processing 4) enhancement of skills of existing stakeholders at the International equipment fabricators to design and Institute of Tropical Agriculture fabricate low cost yam processing (IITA), Nigeria. A similar meeting equipment for small businesses and was organized in Ghana at the CSIR farmer clusters 5) Organize yam Food Research Institute on February farmers into clusters to ease their ability 25, 2014. The purpose of the meeting to access improved inputs, finance, was to share Sahel Capital’s research storage and training support and results on the yam value chain with ensure stronger linkages to processors key stakeholders and obtain feedback 6) Bridge the gap between research and inputs ( Sahel Capital Limited, community and the processing industry 2014). Participants who represented 7) Develop innovative products using the diversity of players in the yam value water yam varieties with significant chain, including farmers, civil society, demand potential for the processing research community, private and public industry ( Sahel Capital Limited, 2014). 366 Product development from Yam in West Africa

Conclusions commodity. Knowledge and access Yam has high health and to processing technologies, including medicinal potential although most equipment, best practices in production, species of the genus remain underutilized processing, food safety as well as and are yet to be exploited as such. To packaging and labeling, are some of adequately explore the potential of the the factors that are needed to realize underutilized species, analysis on their the full potential of yam. There is the unique characteristics and biochemical need to create, validate and coordinate composition is required (Wireko-Manu a production base for yam, since et al., 2014). Although food options are this is a justification for investments quite diverse for yam, more food and in downstream endeavors such as non-food opportunities are available. processing and product development. This diversity creates even a larger Consequently, there will be notable market opportunity that processors progress in advancing the recognition can take advantage of and make long- and utilization of yam as a source of term development plans, supported by food and value-added products (food growth prospects for investment in the and non-food). Product development from Yam in West Africa 367

References

Ackah, D., Agboyi, M. R., & Gyamfi, L. A. (2014). An Investigation of Yam Ingestion Customs in Ghanaian Urban Communities, Ghana. International Journal of Sciences: Basic and Applied Research, 17(2), 374– 411. Adejumo O. (2007). Design and Fabrication of a machine for slicing plantain. Department of Agriculture and Agricultural Extension, Federal University of Technology Akure, Ondo-State, Nigeria. Aderoba, O. (2008). Design and fabrication of a yam tuber peeling and slicing machine for a poundo-yam process plant. Department of Mechanical Engineering, Federal University of Technology Akure, Ondo-State, Nigeria. Adetan, D. A., Adekoya, L. O., & Aluko, O. B. (2006). “Theory of a mechanical method of peeling cassava tubers with knives,.” International Agrophysics, 20(4), 269– 276. Afoakwa, E. O., & Sefa-Dedeh, S. (2001). Chemical composition and quality changes occurring in Dioscorea dumetorum pax tubers after harvest. Food Chemistry, 75(1), 85–91. Ajibola, O. O., Abonyi, B. I., & Onayemi, O. (1988). The Effect of Some Processing Variables on the Dehydration of Pregelled Yam Pieces. Journal of Food Science and Technology, 25, 117–120. Akingbala, J. O., Oguntimehin, T. B., & Sobande, A. O. (1995). Physicochemical properties and acceptability of yam flour substituted with soy flour. Plant Foods for Human Nutrition, 48, 73–80. Akissoe, N. H., Hounhouigan, J. G., Bricas, N., Vernier, P., Nago, M. C., & Olorunda, O. A. (2000). Physical, chemical and sensory evaluation of dried yam (D. rotundata) tubers, flour and amala-A flour-derived product. Tropical Science, 41, 151–156. Anoma, C., & Thamilni, K. J. (2016). Roots and Tuber Crops as Functional Foods: A Review on Phytochemical Constituents and Their Potential Health Benefits. International Journal of Food Science, 2016, 1–15. Ayodeji, S. P., Akinnuli, B. O., & M., O. O. (2014). Development of Yam Peeling and Slicing Machine for a Yam Processing Plant. Journal of Machinery Manufacturing and Automation, 3(4), 74–83. Ayodele, B., Bolade, M., & Usman, M. (2013). Quality characteristics and acceptability of “amala” (yam-based thick paste) as influenced by particle size categorization 368 Product development from Yam in West Africa of yam (Dioscorea rotundata) flour. Food Science and Technology International, 1, 35–49. Baah, F. . D., Maziya-Dixon, B., Asiedu, R., Oduro, I., & Ellis, W. O. (2009a). Nutritional and biochemical composition of D. alata (Dioscorea spp.) tubers. Journal of Food, Agriculture & Environment, 7(2), 373–378. Baah, F. D., Maziya-Dixon, B., Asiedu, R., Oduro, I., & Ellis, W. O. (2009b). Physicochemical and pasting characterisation of water yam (Dioscorea spp.) and relationship with eating quality of pounded yam. Journal of Food, Agriculture and Environment, 7(2), 107–112. Barquar, S. R., & Oke, O. L. (1977). Mineral constituents of Nigerian yams. Nutrition Reports International, 15(3), 265–272. Bhandari, M. R., Kasai, T., & Kawabata, J. (2003). “Nutritional evaluation of wild yam (Dioscorea spp.) tubers of Nepal,.” Food Chemistry, 82(4), 619–623. Bradbury, J. H., & Singh, U. (1986). Ascorbic acid and dehydroascorbic acid content of Tropical root crops from the south pacific. Journal of Food Science, 51, 915–920. Bricas, N., Vernier, P., Ategbo, E., Hounhouigan, J., Mitchikpe, E., N’kpenu, K. E., & Orkwor, G. (1997). The Development of Pounded Yam Machine in West Africa. Journal of Research and Development, 44, 100–114. Chan, Y. C., Chang, S.-C., Liu, S. Y., Yang, H. L., Hseu, Y. C., & Liao, J. W. (2010). “Beneficial effects of yam on carbon tetrachlorideinduced hepatic fibrosis in rats,.” Journal of the Science of Food and Agriculture, 90(1), 161–167. Chan, Y. C., Hsu, C. K., Wang, M. F., & Su, T. Y. (2004). “A diet containing yam reduces the cognitive deterioration and brain lipid peroxidation in mice with senescence accelerated,.” International Journal of Food Science and Technology, 39(1), 99–107. Chen, H. L., Wang, C. H., Chang, C. T., & Wang, T. C. (2003). “Effects of Taiwanese yam (Dioscorea japonica Thunb var. pseudojaponica Yamamoto) on upper gut function and lipid metabolism in Balb/c mice,.” Nutrition, 19(7–8), 646–651. Choi, E. M., Koo, S. J., & Hwang, J. K. (2004). “Immune cell stimulating activity of mucopolysaccharide isolated from yam (Dioscorea batatas),.” Journal of Ethnopharmacology, 91(1), 1–6. Cornago, D. F., Rumbaoa, R. G. O., & Geronimo, I. M. (2011). “Philippine Yam (Dioscorea spp.) tubers phenolic content and antioxidant capacity,.” Philippine Journal of Science, 140(2), 145–152. Ekwu, F. C., Ozo, N. O., & Ikegqu, O. J. (2005). Qualities of fufu flour from white yam varieties (Dioscorea spp). Nigerian Food Journal, 23(1), 107–113. FAO. (1993). Root and Tuber Crop Production. FAO Corporate Document Repository. Accessed 10/10/2016 http://www.fao.org/docrep/x5415e/x5415e01.htm. Product development from Yam in West Africa 369

FAO. (2002). Production Yearbook. Collection FAO Statistics. FAO, Rome, Italy, 55(170). FAOSTAT. (2016). FAOSTAT Domains – Production – Crops. Http://www.food-Info.net/ uk/products/rt/yam.htm. Gallant, D. J., Bewa, H., Buy, Q. H., Bouchet, B., Szylit, O., & Sealy, L. (1982). Ultrastructural and nutritional aspects of some tropical tuber starches. Starch/ Stärke, 34, 255–262. Hou, W. C., Chen, H. J., & Lin, Y. H. (1999). “Dioscorins, the major tuber storage proteins of yam (Dioscorea batatas Decne), with dehydroascorbate reductase and monodehydroascorbate reductase activities,.” Plant Science, 149(2), 151–156. Hou, W. C., Chen, H. J., & Lin, Y. H. (2000). “Dioscorins from different Dioscorea species all exhibit both carbonic anhydrase and trypsin inhibitor activities,.” Botanical Bulletin of Academia Sinica, 41(3), 191–196. Hou, W. C., Lee, M. H., Chen, H. J., Liang, W. L., Han, C. H., Liu, Y. W., & Lin, Y. H. (2001). Antioxidant activities of dioscorin, the storage protein of yam (Dioscorea batatas Decne) tuber. Journal of Agricultural and Food Chemistry, 49(10), 4956–4960. Hsu, F. L., Lin, Y. H., Lee, M. H., Lin, C. L., & Hou, W. C. (2002). “Both dioscorin, the tuber storage protein of yam (Dioscorea alata cv. Tainong No. 1), and its peptic hydrolysates exhibited angiotensin converting enzyme inhibitory activities,.” Journal of Agricultural and Food Chemistry, 50(21), 6109–6113. Http://edition.myjoyonline.com/pages/news/201302/101105.php. (n.d.). Accessed 14/01/2017. Http://foodscience.knust.edu.gh/news/news-items/food-science-department-trains-yam- community-members-on-yam-based-products#. (n.d.). Accessed 14/01/2017. Http://www.food-info.net/uk/products/rt/yam.htm. (n.d.). Accessed 14/01/2017. http://www.foodresearchgh.org/our-products/fufu-flour/yam-fufu-flour. Accessed 14/01/2017. (n.d.). Huang, C.-H., Cheng, J.-Y., Deng, M.-C., Chou, C.-H., & Jan., T.-R. (2012). “Prebiotic effect of diosgenin, an immunoactive steroidal sapogenin of the Chinese yam,.” Food Chemistry, 132(1), 428–432. IITA. (2009). Yam crop – IITA. Retrieved August 26, 2014. Http://www.iita.org/yam. International Institute of Tropical Agriculture, I. (2008). Root and tuber systems. Www. iita.org. Iwata, E, Iwata, E., Hotta, H., & M., G. (2009). The screening method of a bifidogenic dietary fiber extracted from inedible parts of vegetables. Journal of Nutritional Science and Vitaminology (Tokyo), 55(4), 385–388. Iwu, M. M., Okunji, C. O., Ohiaeri, G. O., Akah, P., Corley, D., & Tempesta, M. S. 370 Product development from Yam in West Africa

(1990). “Hypoglycaemic activity of dioscoretine from tubers of Dioscorea dumetorum in normal and alloxan diabetic rabbits,.” Planta Medica, 56(3), 264–267. Kafilat, A. (2010). Physical, Functional, and Sensory Properties of Yam Flour “Elubo” Obtained from Kuto Market – Abeokuta. Department of Food Science and Technology, College of Food Science and Human Ecology, University of Agriculture, Abeokuta, Nigeria. Accessed 14/01/2017 http://www.unaab.edu.ng/ ugprojects/2010bscadedejikk.pdf. Kay, D. (1987). Root Crops Tropical Development and Research Institute. London., 122–1144. Kelmanson, J. E., J¨ager, A. K., & Van Staden, J. (2000). “Zulu medicinal plants with antibacterial activity,.” Journal of Ethnopharmacology, 69(3), 241–246. Komesaroff, P. A., Black, C. V., Cable, V., & K., S. (2001). Effects of wild yam extract on menopausal symptoms, lipids and sex hormones in healthy menopausal women. Climacteric, 4(2), 144–150. Kong, X. F., Zhang, Y. Z., Wu, X., Yin, Y. L., Tan, Z. L., Feng, Y., … Li, T. J. (2009). Fermentation characterization of Chinese yam polysaccharide and its effects on the gut microbiota of rats. International Journal of Microbiology, Article ID, 13. Kordylas, J. M. (1990). Processing and Preservation of Tropical and Subtropical Foods,. Macmillan Publishers Ltd., London and Basingstoke, U.K., 49–71, 128–136, 324–340, 350–374. Lasisi, M. A. (2009). Effect of gelling / firming agents on the proximate, functional and sensory qualities of yam flour for pounded yam preparation. Thesis Submitted to the Department of Animal Production, (Food Science and Nutrition Option) Federal University of Technology. Minna, Nigeria. Liu, Y. W., Shang, H. F., Wang, C. K., Hsu, F. L., & Hou, W. C. (2007). Immunomodulatory activity of dioscorin, the storage protein of yam (Dioscorea alata cv. Tainong No. 1) tuber. Food and Chemical Toxicology, 45(11), 2312– 2318. Martin, F. W. (1974). Tropical Yams and Their Potential. USDA Agriculture Handbook No. 495, Part 3, 40. Meligaard, M., Civille, G. V., & Carr, B. T. (1999). Sensory evaluation techniques 3. Sensory Evaluation Techniques 3rd Ed. Boca Raton: CRC Press. Nindjin, C., Otokoré, D., Hauser, S., Tschannen, A., Farah, Z., & Girardin, O. (2007). Determination of relevant sensory properties of pounded yams (Dioscorea spp.) using a locally based descriptive analysis methodology. Food Quality and Preference, 18(2), 450–459. Noamesi, S. K. (2008). Storability of Dioscorea rotundata Poir. Department of Nutrition Product development from Yam in West Africa 371

and Food Science, University of Ghana, Legon. PhD Thesis. Obadina, A. O., Oyewole, O. B., & Odubanjo, M. O. (2007). Effect of storage on the safety and quality of fufu flour. Journal of Food Safety, 27, 148–156. Olayemi, J. O., & Ajaiyeoba, E. O. (2007). “Anti-inflammatory studies of yam (Dioscorea esculenta) extract on Wistar rats,.” African Journal of Biotechnology, 6(16), 1913–1915. Onayemi, O., & N., P. N. (1974). Preparation and storage properties of drum dried white yam (Dioscorea rotundata Poir) flakes. Journal of Food Science, 39, 539–541. Osagie, A. U. (1992). The Yam in Storage. Postharvest Research Unit, University of Benin, Nigeria. Otoo, E., & Asiedu, R. (2009). Sensory evaluation: The last hurdle in varietal development of yams (Dioscorea rotundata, poir) in Ghana. African Journal of Biotechnology, 8(21). Palaniswami, M. S., & Peter, K. V. (2008). Tuber & Root Crops: Vol.09. Horticulture Science Series. New Delhi: New India Publishing Agency (NIPA). Park, M. K., Kwon, H. Y., Ahn, W. S., Bae, S., Rhyu, M. R., & Lee, Y. (2009). Estrogen activities and the cellular effects of natural progesterone from wild yam extract in mcf-7 human breast cancer cells. The American Journal of Chinese Medicine, 37(1), 159–167. Ross, C. A. (2010). Vitamin A. In: Coates PM, Betz JM, Blackman MR, et al., eds. Encyclopedia of Dietary Supplements. 2nd ed. London and New York: Informa Healthcare, 778–91. Sahel Capital (Mauritius) Limited. (2014). Unlocking Opportunities in the Yam Value Chain. Sahel Capital Partners & Advisory Limited. Accessed 14/01/2017 http:// www.sahelcp.com/files/Sahel%20Newsletter%20Volume%203.pdf. Shang, H. F., Cheng, H. C., Liang, H. J., Liu, H. Y., Liu, S. Y., & Hou, W. C. (2007). “Immunostimulatory activities of yam tuber mucilages,.” Botanical Studies, 48(1), 63–70. Su, P. F., Li, C. J., Hsu, C. C., Benson, S., Wang, S. Y., Aravindaram, K., Chan, S. I., … Yang, N. S. (2011). “Dioscorea phytocompounds enhance murine splenocyte proliferation ex vivo and improve regeneration of bone marrow cells in vivo,.” Evidence-Based Complementary and Alternative Medicine, 2011, 11. Ukatu, A. C. (2002). “Development of an industrial yam peeler,.” Nigerian Journal of Engineering Research Development, 1(2), 45–56. Wang, T. S., Lii, C. K., Huang, Y. C., Chang, J. Y., & Yang, F. Y. (2011). “Anticlastogenic effect of aqueous extract from water yam (Dioscorea alata L.),.” Journal of Medicinal Plant Research, 5(26), 6192–6202. Winger, R., & Wall, G. (2006). Food product innovation. A background paper. Food and 372 Product development from Yam in West Africa

Agriclture Organisation of the United Nations. Agriculture and Food Engineering Working Document. Wireko-Manu, F. D., Ellis, W. O., Oduro, I., Asiedu, R., & Maziya-Dixon, B. (2014). Prediction of the Suitability of Water Yam (Dioscorea alata) for Amala Product Using Pasting and Sensory Characteristics. Journal of Food Processing and Preservation, 38(3), 1339–1345. Woolfe, J. A. (1987). The potato in the human diet. Cambridge Univ. Press. Cambridge, UK. Yam Sector Development Strategy, Ghana. (2013). http://moti.gov.gh/sites/default/files/content/documents/files/Ghana%20Yam%20 Sector%20Dev%20Strategy.pdf. 373

The student breakfast foodscape on the campus of Kwame Nkrumah University of Science and Technology, Kumasi, Ghana

Faustina D. Wireko-Manu1, Arne Wangel2, Niels Heine Kristensen3

1Department of Food Science and Technology, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana [email protected] 2Consultant, Copenhagen, Denmark [email protected] 3School of Restaurant and Culinary Arts, Umeå University [email protected]

Abstract although several food outlets are An experimental study to address the available in campus. In 2016, a survey problem of students skipping breakfast was conducted among students in campus was conducted as part of the Roots and to explore their reasons (see Annex 1). Tuber project. The study adopts the The survey revealed that main reasons concept of food scape to understand given for not having breakfast are: the context of breakfast preferences. Time constraints, religious activities, The objective is to suggest how these financial reasons, had become a habit, preferences may be changed in favour and not considering the breakfast meal of new, local products as an alternative to be as important as the other meals. to those marketing by multinational Almost all of the students interviewed food companies, which contribute to had lunch and dinner though. Only a few the prevalence of life style diseases in of the interviewed students did cooking Ghana. by themselves and their reasons given Introduction included: Home cooking saves cost; In recent years, it has been observed love for cooking; and unsure about the that students enrolled at Kwame hygienic and safety conditions at food Nkrumah University of Science and selling outlets. Technology often skip breakfast, Starting the day on an empty 374 The student breakfast foodscape on the campus

stomach is unhealthy and in no way and tubers for food. They also have conducive for entering into a learning high cultural significance. Despite their situation in the lecture hall. Rather, the importance, root and tubers have many alternative of having a full and nutritious challenges including high postharvest breakfast is likely to support alertness, losses and dwindling utilisation memory and reflection with the students demand especially in urban areas due during morning lectures. In an effort to the tedious nature in traditional to remedy the malpractice, the Roots preparations, inadequate diversified and Tuber project decided to conduct and convenient food forms among an experimental study introducing others. The use of indigenous root and three of the improved pastry products tuber based products in breakfast meals (see chapter by Abena Boakye Achiaa) has the potential to expand the demand developed as part of the options for for the crops, preserve culture and drive upgrading the sweetpotato value chain. production and processing for wealth Among products developed creation among value chain actors in from root and tuber crops by students, the medium to long-term. However, sweetpotato-wheat composite pancake, there is need for these improved root puff loaf and rock buns were selected and tuber products (sweetpotato based for this study (two of each product in this study) to be tested and potential kind: 20% substitution with Apomuden consumer demand evaluated before a orange-fleshed sweet potato flour or decision on their full roll out could be puree). These products were chosen for taken. the fact that they are usually consumed The concept of food scape together with other meal components at The social science approach to the breakfast or alone as snacks on campus. analysis of students’ breakfast practices Root and tuber are crops that is based upon the concept of food scape. develop starchy roots, tubers, stems, This concept obviously reaches beyond bulbs or corms that act as food stores the individual food item to capture a for the plant (Folorunso et al, 2013). context of meal preparation, eating They are important staple crops in practices and human health. Foodscape Ghana and serve as major source of research in particular addresses income and livelihood for farmers, environments of ‘captive serving’, e.g. processors and traders, and a major the school lunch. In the literature the source of food with over 80% of the 24 concept of food scape is defined by a million Ghanaians depending on roots The student breakfast foodscape on the campus 375

range of characteristics, such as.: Drawing on these characteristics, • Being contextual and inter- one definition of food scape relational reads: ‘physical, organizational and • Foodscapes as filled with socially sociocultural spaces in which clients/ constructed and culturally learned guests encounter meals, food and habits, patterns, rituals, practices food related issues including health and scripts messages’ (Mikkelsen 2011, 2009). • Place’ is important The concept is considered particularly • The physical food stores and well suited for studies investigating outlets in a specified structural ‘the role that captive eating-out-of- planning context (e.g. Winson, home environments (CEOE) in public 2004, Morgan, 2008) welfare systems has on the health of • As a way to capture a nutritional the individual and on the sustainability setting for example a kitchen or of the environment’ (ibid.). Obviously, a plate with food on it. The food the response of the individual efforts to architecture. The overall purpose influence food consumption behaviour is to improve health of the eater in the context of a captive environment (e.g. Sobal and Wansink, 2004) is crucial. Mintel describes five • As a way to capture a system different ‘archetypes’ in meeting the approach by describing food message about healthy food choice: the systems and their implications Strugglers, who would like to make towards the food production and changes in their lifestyle but need gentle consumption (e.g. Johnston and persuasion, Happy Healthies who are Biro, 2009; Winson, 2004) health committed, Natural Alternatives • As a way to describe the interaction who are actively maintaining their between the eater and the eaten healthy lifestyle, and Persistent Strivers and thereby underline the cultural who have lifestyle problems but are aspects of the meal (e.g. Dolphijn willing to put in the effort to make 2005; Brembeck and Johansson, changes. They will also benefit from 2010: Adema, 2007) the message. However, the Fatalists are • Aesthetics of food as a design most likely to consume unhealthy foods discipline or design perspective and are not willing to make any changes (e.g. Johnston and Biro, 2009) (Mintel, 2008). • A term that tries to capture food, In Ghana, initial clues to the space, place and people student breakfast foodscape in campus 376 The student breakfast foodscape on the campus

include a concern about food fraud, the The sensory evaluation of the family background of students, and a newly developed food items (Annex push for entrepreneurial initiative in 2: Evaluation protocol) prior to the many lines of study. The experience experimental serving in campus of food fraud and also the risk of food was conducted using 60 students poisoning from unhygienic conditions on several occasions and by asking are a significant cause of concern. workshop participants to complete Another factor in shaping the response short questionnaires. An observation of students may originate from their and interview study of current breakfast family regime; the food practices practices of students in campus (Annex experienced during childhood may be 3: Interview guide) was carried with carried over into adult life. Also, the students at their residential halls and emphasis on entrepreneurship among with food sellers. Interviews were students and in teaching in KNUST may audiotaped, transcribed and a content count towards the food stall business analysis conducted. and the willingness to experiment with The sensory evaluation of the new food products. new items was repeated as real-life serving of breakfast at a few outlets Methods in campus. Groups of students were To build capacity of students and interviewed using a qualitative focus traders for future up take, the entire study group interview approach (Annex 3: was done with existing commercial Interview guide), while observations breakfast stands (sellers at three halls on the final preparation, serving of the of students’ residence, one new koko food, and the arrangement of breakfast set up stand at Bioscience faculty, and consumption next to a food selling stall one yoghurt stand at the Agricultural were photographed and noted. Again, faculty area (students who don’t take interviews were audiotaped, transcribed breakfast usually patronize yoghurt and a content analysis conducted. late morning at the faculty). Students on Finally, the student assistants, who campus were the potential consumers had conducted the observation and and master students on the project; final focus group studies performed a re- year students and teaching assistances enactment of what they perceived as were trained and used as moderators students’ breakfast practices through an in the focus group interviews, product almost spontaneous roleplay created in preparation and data collection. an auditorium. The student breakfast foodscape on the campus 377

Findings in their early childhoods by their parents The interviews with students before going to school. show that norms and routines in the Students are willing to take family home during childhood in breakfast provided their constraints: general no longer govern the students. time, availability and cost, are In transition to become a young adult, addressed. To this, students suggested life is often unstructured, in particular the following: for male students. However, a few have 1. The possibility of starting learned to cook in their family home lectures very early so that an hour or and are doing well. There seems to be more break is given between 8 to 9 am a difference between 1st year students for them to have good breakfast instead living in campus, and other students of the current 30 min break between 10 coming from outside campus, which and 10:30am. need to be studied further. Some female 2. Have good but different students stock ingredients in their room breakfast foods available at faculty for cooking. Male students are not area for students to choose from. organised in terms of cooking, which They expressed that good breakfast may lead to social isolation. Many should have components from cereals staying in campus prefer to eat in their products such as koko, tombrown, oat room and have the food brought to their etc; beverage based such as milo, tea, doorstep. coffee, yoghurt, juices etc, pastry based From the focus group interviews, such as bread, pancake, doughnut, majority of students’ skip breakfast as rock buns etc, together with sausages, revealed by earlier preliminary studies kitchen and salad. Others prefer heavy for many reasons including too early breakfast such as kenkey and fish, gari morning lectures, unavailability of and beans, waakye and even fufu. their ideal breakfast and the cost of it. 3. Willingness to pay between Not eating breakfast has become habit 5-10 cedis for their ideal breakfast for most students who would rather eat instead of the current average of 3 cedis brunch (breakfast and lunch together) that is spend on light breakfast. in late morning even during weekends. Over 80 percent of students who According to students, this is not the took part in the sensory evaluation normal home practice where breakfast liked pancake, puffloaf and rock buns is served between 6:30 to 9am. The and either consume them as snack or majority were forced to each breakfast as part of breakfast meal (Fig 1, 2, and 378 The student breakfast foodscape on the campus

3). Preference for the products, either willingness to buy the products when with flour or puree substitution were introduced and even proposed to pay very good even though majority of the between 50 pesewas and one cedi as the students preferred the ones made with existing pastries (without sweetpotato) sweetpotato flour to the puree (Fig. 1, are sold. This indicates that the 2 and 3). The differences in the two sweetpotato incorporated pancake, forms (flour and puree incorporated) puffloaf and rock buns could easily of products according to the students be accepted by consumers on KNUST were texture, taste and flavor. The level campus. Aside enhancing the utilisation of preference for all the different pastry of sweetpotato for the benefit of value products show diversity in consumers chain actors, the high beta-carotene in and also the potential for root and tuber the orange fleshed sweetpotato used incorporated pastries to do well when will enhance the vitamin A status introduced. of consumers. Studies conducted Between 50 to 85% of students in Sub-Saharan Africa showed that were willing to consume the introduced consumption of food products from products with yoghurt or koko, a orange fleshed sweetpotato (OFSP) traditional breakfast porridge prepared improved vitamin A status of children from millet. The students affirm their (Amagloh et al. 2012).

Figure 1: Consumer preference of pancake

p378 – pancake from Apomuden puree p567 – pancake from Apomuden flour The student breakfast foodscape on the campus 379

Figure 2: Consumer preference of puffloaf

P632 – puffloaf from Apomuden puree P805 – puffloaf from Apomuden flour

Figure 3: Consumer preference of rock buns

P265 – rock buns from Apomuden puree P962 – rock buns from Apomuden flour 380 The student breakfast foodscape on the campus

Conclusion: Some emerged. Future research could explore suggestions for change the observation mentioned above, that The breakfast food scape for students there seems to be a difference between in the KNUST campus could be 1st year students living in campus, and enhanced as a captive eating-out-of- other students coming from outside home environment initially by simple campus. measures. One line of action targets the Also, vendors in campus have low students themselves. Cooking classes social status, and some are illiterate; this could be offered to students, maybe may be a barrier for upgrading quality. already in the schooling system for The license to a vendor is in some cases both female and male students. Longer passed on to the next generation in the break time between lectures could be family. There is a differentiation among scheduled to allow students to reach food stalls in campus, how can that the nearest stall for a meal. For the best be described: street food, cantinas, same purpose, the location of food cafés? stalls could be optimized. In marketing Are different food stalls new breakfast diets, emphasis on local frequented by student customers for origin of breakfast products could different needs? Is one type of food be established, if that represents a stall best suited for introducing a new significant motivation. Specifically, breakfast item? Is nudging an option the sweetpotato incorporated products in Ghana? If yes, what could be an should be introduced with cheaper example of effective nudging in Ghana? breakfast ingredients such as the In the context of Ghanaian traditional traditional porridge, koko, plus other food culture, are social norms about breakfast components at faculty areas food and health weaker compared for students. to other national cultures? How is the relationship between sayings vs. Future research doings? What is the outlook for the While the study has produced evidence prevalence of life style diseases given for practical intervention, at the current meal practices of students and same time additional questions have youth at large in Ghana? The student breakfast foodscape on the campus 381

References

Adema, P. (2007). Foodscape: An emulsion of landscape and food. Gastronomica, vol. 7 (no.1, 2007): 3. Amagloh, F. K. (2012). Sweetpotato-based complementary food for infants in Ghana: a thesis presented in fulfilment of the requirements for the degree of Doctor of Philosophy in Human Nutrition, Institute of Food, Nutrition and Human Health, Massey University, Palmerston North, New Zealand. Brembeck, H., and Barbro, J. (2010). Foodscapes and children’s bodies. Culture Unbound: Journal of Current Cultural Research. 9 (5): 707-818. Dolphijn, R. (2004). Foodscapes: Towards a Deleuzian Ethics of Consumption. Delft: Eburon. Folorunso S. T., Adeola, S. S. and Gama, E. N. (2013). Profitability analysis of small holder root and tuber crop production among root and tuber expansion programme farmers in Plateau state, Nigeria. Pelagia Research Library Advances in Applied Science Research, 4(3):1-4 ISSN: 0976-8610 CODEN Johnston, J., Biro, A. and MacKendrick, N. (2009). “Lost in the Supermarket: The Corporate-Organic Foodscape and the Struggle for Food Democracy”. Antipode. 41 (3): 509-532. Mikkelsen, B. E. 2011. “Images of Foodscapes: Introduction to Foodscape Studies and Their Application in the Study of Healthy Eating out-of-Home Environments.” Perspectives in Public Health 131 (5): 209–16. doi:10.1177/1757913911415150. Mintel Group (2008), Healthy Lifestyles: Buying into, or Barriers to Overcome? – UK – January 2008, Mintel Group, London, available at: http://academic.mintel. com/sinatra/oxygen_academic/search_results/show&/display/id=291686/display/ id=318418/display/id=318376#atom11 Morgan, Kevin. 2008. Local and green vs global and fair: the new geopolitics of care. Cardiff: BRASS Centre. Sobal, Jeffery, and Brian Wansink. 2007. “Kitchenscapes, Tablescapes, Platescapes, and Foodscapes.” Environment And Behavior, 124–42. Winson, Anthony 2004. Bringing Political Economy into the Obesity Epidemic. January 2004. Agriculture and Human Values 21(4):299-312. DOI10.1007/s10460-003- 1206-6 382 The student breakfast foodscape on the campus

Annex: Survey on Findings students eating patterns It was discovered that breakfast was on KNUST campus the most skipped meal of the day. This report is a summary of surveys Over 50% of the students interviewed independently conducted by nine (9) skipped breakfast. . Almost all of the second year students of the Traditional students had lunch and dinner though. Foods and Nutrition class of 2015. The Reasons given for skipping methods for data collection included breakfast include, time constraints, the use of questionnaires, interviews religious activities, financial reasons, and non-participant observations. skipping breakfast had become a Collectively, the studies aimed at habit, other taught did not consider determining the patronage of traditional the breakfast meal to be as important foods as well as the eating patterns of as the other meals. Figure 1 show students on campus. The overall sample the distribution of reasons given for size was 280. skipping breakfast from two locations (Hall 7 and West End hostel).

Figure 1: Reasons for skipping breakfast by some students The student breakfast foodscape on the campus 383

Generally, students usually ate their of them actually cook. Reasons given first meal of the day between 11am by the few who cooked include: and 1pm. Some attributed this • Cooking saves cost on food to the fact that eating heavy meals at • Love for cooking this time could take them through the • Not sure of the hygienic whole day until they ate dinner, hence and safety conditions with minimizing expenditure on food. regards to sold foods In view of the reasons stated above, On the whole, skipping breakfast is students mostly depend on buying food increasingly becoming the trend and outside rather than cooking especially habit of students and young adults during examination periods. Only a few within KNUST. 384

THEME III:

PRODUCTION, PROCESSING AND MECHANIZATION ISSUES IN THE GHANAIAN ROOT AND TUBER INDUSTRY 385

INFLUENCE OF FERTILIZER APPLICATION ON POSTHARVEST STORAGE OF WHITEYAM TUBERS

A.K. Aidoo, E*. Owusu Danquah, F. Frimpong, S.A. Ennin, E. Adu-Kwarteng and Z. Appiah-Kubi CSIR-Crops Research Institute, P.O. Box 3785, Kumasi, Ghana. *Corresponding email: [email protected]

ABSTRACT Healthy – looking whiteyam tubers Yam growers across major growing were randomly selected from a areas are being encouraged to fertilizer application trial in Ejura- increase harvest yield through Sekyedumasi district and storage the application of fertilizer at the rot experiment set-up at CSIR-CRI recommended rate and time. Ghana, (on – station). Initial parameters taken which is the leading exporter of yam were tuber weight, yield and moisture in Africa is currently threatened content. Temperature and relative by poor tuber storability. Large humidity were periodically recorded. quantities of yam exported to the Rot assessment were done at 3rd, US from Ghana were rejected, with 4th, 5th and 6th months of storage. an estimated loss of 30-60% of sea Rot analysis parameters taken were and air-freight imports found to be tuber weight, number of rotten tubers, unwholesome upon arrival in that rotten tissue weight, rot initiation country. Some actors along the food point, rot type and associated value chain attribute most storage pathogens. Major fungi identified rots to the application of fertilizer by from rotten tissues over the period farmers. This study was conducted were: Lasiodiplodia theobromae, to investigate into the claim that Fusarium oxysporum, Penicillium fertilizer application has effect on the sp., Rhizopus sp., Aspergillus flavus shelf life of most whiteyams. Five etc. About 54% of rotten tubers were fertilizer application levels, including the dry rot type. There was apparently a control (no fertilizer application) no significant difference in terms of were tested on two white yam rot incidence and severity among cultivars, Serwa and TDr 95/19177. the fertilizer application levels as 386 INFLUENCE OF FERTILIZER APPLICATION ON POSTHARVEST STORAGE

well as the control. However, varietal to increase harvest yield through differences and tuber sizes were the application of fertilizer at the key factors identified as having recommended rate and time. However, effect on storage rots. Currently, export of yam tubers from the country to other investigations are underway on the global world is currently threatened some important whiteyam varieties by poor tuber storability, which has like Pona and Dente to evaluate the led to reduced income generated from influence of fertilizer application on its export as some consignments are their shelf life. rejected and returned. Keywords: fertilizer application, Some actors along the food storage rots, whiteyams and storability. value chain speculate that fertilizer application by farmers’ affects the INTRODUCTION shelf life of whiteyam tubers. In 2014, Whiteyam (Dioscorea rotundata) a large quantities of yam exported to are produced in Ghana for both local the US from Ghana were rejected (30- consumption and the export market. The 60% of sea and air freight imports), as country is currently among the leading most were found to be unwholesome exporters of yam in the world (export upon arrival in that country (MoFA, of about 12,000 tonnes annually) (FAO, 2014). These yam importing agencies 2005). Yam is produced mostly in the attributed these losses to chemical Guinea-Savanna and Forest-Savanna fertilizers applied by farmers. The transition zones. However, reasonable Ministry of Trade and Industry (MoTI) production occurs in almost all regions. confirmed the report and promised White yam is much preferred to the that steps to resolve this problem are other yam varieties and it constitutes underway (GhanaWeb, 2014). about 80% of total yam produced in MoFA organized a national stakeholders’ in the country (Tetteh and Saakwa, forum in an effort to finding a lasting 1994). Water yams (D. alata) are only solution to the problems of yam consumed when whiteyam becomes production, handling and export. A scarce or expensive. The average key outcome from this forum was the daily consumption of yam in Ghana recommendation that investigations is currently 300 kcal per capita (FAO, into the effect of fertilizer on yam 2013). deterioration should be done and results Yam growers across major used to address the problem. In view growing areas are being encouraged of this, Aidoo et al. (2016), conducted INFLUENCE OF FERTILIZER APPLICATION ON POSTHARVEST STORAGE 387

studies on the effect of four different Healthy-looking whiteyam tubers fertilizer application models on storage of Serwa and TDr were randomly rots of two white yam varieties (ie. selected from fertilizer application Serwa and TDr/95/19177). This trials in Ejura-Sekyedumasi District, piece of work therefore had the aim Ashanti Region, Ghana. In all about of determining the effect of fertilizer Three hundred tubers were collected application on rots of stored whiteyam and brought to the station. tubers in Ghana. Experimental Set-up and Design: The experimental design employed was MATERIALS AND METHODS Split plot with three replications. The Experimental Site: main plot represented the two varieties The experiment was carried out in the (Serwa and TDr 95/19177) whilst the Yam barn of CSIR-Crops Research sub-plot was the fertilizer models (M1, Institute, Kumasi. M2, M3, M4 and M5) as shown in the Sampling of Experimental Materials table below. The tubers were randomly arranged in the yam barn and labelled. Table 1: The models below represent the various treatments for this experiment

Model 1 (M1) Model 2 (M2) Model 3 (M3) Model 4 (M4) Model 5 (M5)

Fertilizer Fertilizer 30:30:36 38:23:50 Fertilizer Fertilizer N:P 0 :K 0 kg/ N:P 0 :K 0 kg/ha 45:45:60 2 5 2 2 5 2 Farmers’ Practice 45:45:60 ha plus 15 kg/ha + 5 kg/ha MgO N:P 0 :K 0 kg/ to be monitored N:P 0 :K 0 kg/ha 2 5 2 Mg and 20 kg/ha + 8 kg/ha S + TE 2 5 2 ha plus Agrolyzer to obtain costs of (best CRI S as MgSO (best (Yara Winner granules tested on 4 production. research result) of models tested NPK formulation cassava in Nigeria in N. Ghana and available in Ghana Nigeria). market)

Data Collection and Analysis and 3.00 pm in the afternoon. After Initial parameters taken when samples the third month of storage, the tubers were brought to the yam barn from were examined and data collected. the field were tuber weight and Parameters collected for rot evaluation moisture content. Temperature and are weight of tuber, number of rotten relative humidity of the storage barn tubers, and weight of rotten tissue, rot were measured weekly with the use initiation point, rot type and associated of a thermo-hygrometer. Readings rot pathogens. These data were also were taken at 9.00am in the morning taken in the fourth, fifth and sixth 388 INFLUENCE OF FERTILIZER APPLICATION ON POSTHARVEST STORAGE

months of storage period. analysis was done. Rot incidence was calculated RESULTS by: no. of rotten tubers/ total no. of The barn had average temperature tubers x 100 between 25 – 30 OC with an average Severity of rot was calculated relative humidity of 77.86% over a by: weight of rotten tissue/weight of period of three months. Three categories tuber X 100 of rot were observed on the stored The data was analysed and tubers. These are soft, dry and wet rots. interpreted using Genstat package About 61% of the total number of rots and simple statistical tools. Data for recorded were the dry type, whilst soft rot severity was transformed by using and wet rots recorded 34% and 5% square root transformation before respectively (Figure 3).

Major rot pathogens recorded over the incidence of the two varieties during period were Lasiodiplodia theobromae, storage. After the six months of storage, Fusarium oxysporum, Penicillium sp., the average rot incidence for Serwa and Rhizopus sp., Aspergillus flavus and A. TDr 95/19177 were about 28% and 34% niger. These organisms are identified respectively. The highest incidence by other researchers to be associated of rot for both varieties was recorded with storage rots of whiteyams across by M4 (35% and 40% respectively). the globe. Figures 4 and 5 shows From the graphs, differences in rot the graphical representation of rot incidences among the treatments were INFLUENCE OF FERTILIZER APPLICATION ON POSTHARVEST STORAGE 389

not significantly different from each other.

Similarly, there were no significant statistical analysis show that fertilizer differences among the five treatments application does not have significant in terms of rot severity for both varieties effect on storability of whiteyam (Table 1). These initial results from the cultivars.

Table 1: Effect of fertilizer application rot severity of yam tubers (Serwa and TDr 95/19177) stored for six months. Fertiliser application type (% rot) Whiteyam variety M1 M2 M3 M4 M5 Serwa 1.193 0.818 0.808 1.211 0.889 TDR 95/19177 0.918 0.934 0.865 0.870 0.879 LSD (P <0.05)= 1.0844 SED(P <0.05)= 0.5086 CV%= 64.00 390 INFLUENCE OF FERTILIZER APPLICATION ON POSTHARVEST STORAGE

DISCUSSIONS The combined effects of cultivar Asieku et. al. (2015), reported that and manuring treatments on rotting there was high significant difference in incidence varied with cultivar type. percentage rot of yam as a result of the For example, ‘Amula’ cultivar had combined application of organic and the highest rotting incidence with or inorganic fertilisers. Tuber rot score at without manuring treatments, whereas storage was greatest in the combined Danacha and Ezakwukpolo had organic and inorganic fertilizer statistically similar rotting incidence treatment, which was significantly with any of the manuring treatments. higher than all other treatment effects. In conclusion, evidences in this study All other treatment differences show that postharvest losses of yam were statistically similar. However, are, in part due to field management percentage rot difference was not but mostly dependent on species and significant amongst individual (sole) cultivars (Eze and Orkwor, 2010). fertilisers applied at the recommended CONCLUSION rates. This piece of work confirms that In summary, yam export market and chemical fertilizers if used appropriate its pride as a food security crop is do not have adverse effect of stored under threat due to the perception whiteyam tubers. that chemical fertiliser application Other factors such cultivar type is affecting its storability. Getting a and tuber size are very important in the lasting solution to the concerns have shelf life of most whiteyams. Asadu been raised by stakeholders. Awareness (1995) indicated that type of cultivar creation among farmers, exporters and could play a role in high rotting rate of other stakeholders on this issue, findings stored whiteyam tubers. Gray (1996) and recommendations is necessary to observed pona to be more perishable find a lasting solution the problem. and susceptible to rotting under storage This preliminary results indicate that compared to other varieties of D. there is apparently no effect of fertliser rotundata species. In Nigeria, rotting application on the postharvest shelf life was significantly higher in the cultivar, of whiteyam tubers. Studies should be ‘Amula’ with the application of NPK undertaken extensively under different fertilizer compared with ‘Danacha’, storage conditions practiced by farmers ‘Nwaopoko’, ‘Ezakwukpolo’ and and at different ecological zones. ‘Pepa’. INFLUENCE OF FERTILIZER APPLICATION ON POSTHARVEST STORAGE 391

REFERENCE

Asadu, C.L.A. 1995. Traditional/field storage practices intended to promote shelf life of yam in southeastern Nigeria. A paper presented on pests and pathogens of yam in storage at the International Institute of Tropical Agriculture (IITA) Ibadan, Nigeria; Asieku, Y., Otoo. E. & Asare, E, 2015. Yield and storage characteristics of whiteyam (Dioscorea rotundata Poir) as influenced by fertilizer application and time of harvesting in forest zone of Ghana. Jr. of Sci. Res. & Rep. 8(6):1-7 Eze, S.C. and Orkwor, G.C. 2010. Studies on effects of mineral fertilizer, organic manure and cultivar on the yield and storability of Yam (Dioscorea rotundata Poir). Afri. Jr. of Food, Agri., Nut. & Dev. 10(6): 2755-2771 F.A.O. 2005. FAO Annual Report. Food and Agriculture Organisation Production Year Book. FAO Rome F.A.O. 2013. Agribusiness Public Private Partnerships: A country report of Ghana. Food and Agriculture Organization of the United Nations, Rome GhanaWeb Report. 2014. Ghana’s yam rejected. http://www.ghanaweb.com/ GhanaHomePage/ economy (date accessed: 3/3/2016). Gray, A. 1996. Report on yam marketing in Ghana. Project A0497; R6505. Chantham: Natural Resource Institute. Tetteh, J.P., & Saakwa, C. 1994. Prospects and constraints of yam production in Ghana. In proceedings of 9th symposium of the International Society for Tropical Root Crops. Ofori and Halm. Accra, Ghana. 20-26 pp.ed: 10-032008) 392

Biocontrol of Meloidogyne spp. using Arbuscular mycorrhiza in root and tuber cropping systems

Seloame T. Nyaku1 and Uta Paszkowski2 1Departmet of Crop Science, College of Basic and Applied Sciences, University of Ghana, P.O. Box LG 44, Legon-Accra, Ghana, 2Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge, CB2 3EA, Abstract plant species (>80%).These organisms Nematodes are very diverse and improve plant growth with higher found in almost all environments. One nutrient uptake for the host plant devastating pest on yam, cocoyam, in return for photosynthetic carbon cassava and sweetpotato is the sedentary usually obtained from its host crop. endoparasite, Meloidogyne spp. which This chapter initially focuses on the if not properly managed in a timely advantages obtained from application manner results in total crop losses. of AMF to root and tuber crops in In managing Meloidogyne spp., terms of their growth development and nematicides are utilized as a quicker yield increase. Other thematic areas means of control, however, their usage discussed are 1. The current status and is limited because of human health and applications of AMF in bio-control of environmental concerns. Research in Meloidogyne, 2. The advantages in Ghana on nematode management in soils application of native over commercial has been through organic amendments inoculants for nematode management and pathogenicity tests on the root and and yield of root and tuber crops, and tuber crops to the nematodes. Biological 3. The various mechanisms used by control of Meloidogyne is therefore an AMF in bio-control of nematodes. The environmentally friendly management different mechanisms are not mutually option and arbuscular mycorrhizal independent and bio-control may fungi (AMF) can be considered for this results from a combination of different purpose. Arbuscular mycorrhizal fungi mechanisms. are obligate symbionts, proliferating extensively inside plant roots of most Biocontrol of Meloidogyne spp. using Arbuscular mycorrhiza 393

Introduction and sweet potato whose acreages are Root and tuber crops provide several much lower, compared to cassava calories to feed people in the developing and yam. These root and tuber crops countries. Cassava (Manihot esculenta are susceptible to biotic stress among Crantz) is native to Central and South these, the plant parasitic nematodes American and provides food for over 800 Meloidogyne spp. and Scutellonema million people in developing countries bradys are a particular nuisance to (Burns et al., 2010). In Ghana, cassava productivity, tuber quality, storage, and acreages for year 2011 were greater than seed viability (Adegbite et al., 2005). 13,000,000 MT (FAOSTAT, 2012). Yam However, these root and tuber crops provides more than 200 calories each can be protected from these devastating day to about 60 million humans, and pests through numerous benefits is second to cassava in its importance offered by arbuscular mycorrhizal fungi as a food security product and in its (AMF). The AMF is in the phylum production (FAO, 2013). Although Glomeromycota (Schüßler et al., 2001), acreages of yam production keeps and forms mutualistic associations with expanding, its yields keep dwindling plant roots using various mechanisms. than expected in West Africa (IITA, A main function of AMF is in nutrient 2014). In Ghana, yam is utilised in (phosphorus and nitrogen), and water local dishes e.g., ‘fufu’ (pounded yam) provision to the mycorrhizal plant (He and “ampesi” (boiled yam). Ghana is et al., 2003; Smith and Read, 2008). among the major exporters of yam in These fungi also enable the host plant to West Africa sub-region, providing 94% tolerate other biotic and abiotic stresses yam exports. Yam also contributes (Pozo and Azcón – Aguilar, 2007; to 16% of Ghana’s agricultural gross Porcel et al., 2011; Augé et al., 2015). domestic product (FAOSTAT, 2012). The numerous benefits derived from Huge acreages of yam cultivation in AMF has led to native strains being Ghana are within the Northern, Brong- used as bio-fertilisers for enhanced root Ahafo, and Ashanti regions (Osei et al., and tuber plant growth and yield, and 2004). nematode management (Gapasin, 1996; In 2011, Ghana produced about Tchabi et al., 2016, Sieverding, 1989; 6,295,450 MT of yam, an equivalent Cardoso and Kuyper, 2006; Ceballos et of $1,605,616 (FAOSTAT, 2013). al., 2013; Jean-Marc Sery et al., 2016). Other root and tuber crops cultivated There are commercial inoculants by farmers in Ghana include cocoyam produced from the AMF strains, 394 Biocontrol of Meloidogyne spp. using Arbuscular mycorrhiza

however, these have some limitation spp.), three white flesh yams (Tainung which can be linked to competition 1,Tainung 2, and Ercih) and two purple from native AMF communities and flesh yams (Zihyuxieshu and Tainung the associated costs in obtaining these 5) provided by yam farmers in Nantou, (Plenchette et al., 2005). Taiwan were used (Lu et al., 2015). Six species of AMF, (Glomus clarum, Mycorrhizal fungi for increased G. etunicatum, G. fasciculatum, plant growth, development, Gigaspora sp., G. mosseae, and yield and secondary metabolite contents in root and tuber Acaulospora sp.,) were inoculated crops into the yam varieties. Mycorrhizae Arbuscular mycorrhizal fungi (AMF) colonization rates ranged from 63.33% interactions with root and tuber crops to 90%. Increase in tuber weights were enhance plant growth and development observed, and treatments that received and also improve yields (Lu et al., G. etunicatum inoculation had high 2015; Tchabi et al., 2016). In vitro tuber weights of 39%, 35%, 20%, meristem tissue culture of yam has 56%, and 40% for Tainung 1, Tainung the potential of providing disease – 2, Ercih, Zihyuxieshu, and Tainung 5, and pest-free planting material (IITA, respectively. Secondary metabolites, 2006). These plantlets once produced, e.g., polyphenols, flavonoids, and lack their natural protective endophytic anthocyanin, increased to 40%, 42%, microorganisms e.g., AMF, mostly with and 106% respectively, in tuber flesh beneficial properties (Cassells, 2012). and peels of all the yam species that Studies have shown the importance received the AMF inoculum. Yield of of secondary metabolism leading to tubers that received the AMF inoculum secondary metabolite production in were higher compared to controls. plants (Araim et al., 2009; Yaghoub and A pot experiment was recently conducted Weria, 2013). Arbuscular mycorrhizal in a greenhouse in IITA, Benin, and the fungi, are also responsible for the impact of AMF on micro-propagated synthesis of caffeic acid and rosmarinic hybrid yam growth and yield inoculated acid in sweet basil (Ocimum basilicum), with Meloidogyne incognita was a medicinal plant (Toussaint et al., studied (Tchabi et al., 2016). Although 2007). AMF colonisation rates were low (6%), In a study on tuber weight and there were increases in the yam growth. secondary metabolite content in five Root dry weights were significantly commercial species of yams (Dioscorea higher in yam-AMF-Meloidogyne Biocontrol of Meloidogyne spp. using Arbuscular mycorrhiza 395

treatments compared to treatments that al., 2005a; Steinkellner et al., 2007). did not receive any AMF. The quality Certain root secretions obtained from of tubers that did not receive any AMF mycorrhizal plants poses a lipophilic inoculation were poor, due to high signal (lysophosphatidylcholine) galling. which stimulate two P transporter genes The AMF inoculated plants have (StPT3 and StPT4) of potato (Drissner the potential to increase yields in terms of et al., 2007). their numbers and weight (Vosatka and There is evidence to show that, Gryndler, 2000). Micro-plants of potato AMF contributes the yield increases in inoculated with three commercial AMF cassava (Sieverding, 1989; Cardoso and inoculants had higher yields which Kuyper, 2006; Ceballos et al., 2013). In varied with respect to mycorrhizal a field study by Jean-Marc Sery et al. isolate and host plant genotype (Duffy (2016), native AMF strains associated and Cassells, 2000). Field experiments with cassava isolated from three agro- using commercial inoculants of AMF ecological regions in Cote d’Ivoire, (Glomus intraradices) produced were compared to a commercial AMF higher yields and much bigger tubers (MykePro). Acaulospora colombiana compared to treatments in which single and dual inoculations significantly chemical fertilizers were used over two had positive impact on cassava yields, growing seasons (Douds et al., 2007). compared to the commercial inoculant. The AMF enhanced potato tuber size Acaulospora colombiana also provided and yield, partly because of high P the cassava plants with the ability to uptake (McArthur and Knowles, 1993). tolerate water stress and may have In growth and development of also contributed to photosynthetic AMF, flavonoids play useful roles capability because of increase levels of biological roles in soils (Davies et total sugars and chlorophyll (Mathur al., 2005a; Requena et al., 2007). and Vyas, 1995). Increase in potato tuber dry mass Rhizophagus irregularis which can be attributed to production of is also an AMF has also been shown formononetin (Davies et al., 2005b). to significantly increase yields of In greenhouse studies, formononetin crops including cassava (Ceballos et enhanced fungal extraradical al., 2013; Angelard et al., 2010). Two development, net photosynthesis and field experiments were conducted in stomatal conductance. This stimulated Columbia (La Salle University-Yopal, higher potato tuber yields (Davies et Casanare and Santana) to evaluate the 396 Biocontrol of Meloidogyne spp. using Arbuscular mycorrhiza

efficacy of Rhizophagus irregularis on Applications of AMF for cassava growth (Ceballos et al., 2013). Meloidogyne spp. and The fungus was produced in an in-vitro Scutellonema bradys system of Agrobacterium rhizogenes – management in root transformed carrot roots. Two Cassava and tuber crops varieties (MCOL2737 and COL2215), In a recent pot study conducted in were selected based on their common Benin, two cultivars each of Dioscorea use by farmers in the communities. alata (TDa98-01183 and TDa98- Results in Santana showed that, 165), and D. rotundata (TDr97-00551 although the AMF had significant and TDr 745) micro-propagated influence in cassava yields, these were plantlets inoculated with two types of not the same at the various phosphate Arbuscular mycorrhiza (Funneliformis (P) quantities applied to the plants. mosseae and Glomus dussii) and High cassava yields were produced in also with 500 infective juveniles of cassava fields that received 50% P and Meloidogyne spp. produced higher the AMF. However, in non-inoculated yam yields and a reduction in gall cassava plots (control), high yields formation (Tchabi et al., 2016). The occurred only with 100% P inoculation. pots were kept in the greenhouse over In Yopal, cassava yield was enhanced 7 months for development of the yam by the AMF inoculation. Plants that plantlets. In the above experiment received the AMF inoculation, has both Funneliformis mosseae and weights of 20% higher compared to the G. dussii were not locally obtained non-inoculated plants. as these were commercial inocula. The highest yields were in plots These were ordered from BIORIZE© that received AMF inoculation together (Dijon, France). Results indicated with 100% P fertilisation. However, Funneliformis mosseae inoculation plots without AMF inoculation and produced a greater root colonization either 0% or 100% P fertilisation, had for TDa98-01183 compared to G. the least yields. dussii (p = 0.03), however, root colonizations were generally higher in (TDr cultivars) inoculated with G. dussii than those receiving F. mosseae (P=0.03) inoculations. These two commercially avialable mycorrhiza (Funneliformis Biocontrol of Meloidogyne spp. using Arbuscular mycorrhiza 397

mosseae and Glomus dussii) were also (Jean-Marc Sery et al., 2016). In this applied on yam plantlets to control study, native AMF strains associated the nematode Scutellonema bradys with cassava were isolated from three (Tchabi et al., 2016). In this study agroecological regions (Abengourou, conducted at the International Institute Azaguie, and Yamoussoukro), in Cote for Tropical Agriculture (IITA)-Ibadan, d’Ivoire. Among the various species two Dioscorea alata cultivars (TDa98- of AMF identified within the cassava 01183 and TDa98-165), and two rhizospehres, there were seven (7) Dioscorea rotundata cultivars (TDr97- species that were more abundant on 00551 and TDr 745) were used. The the soils. However, there were two micro-propagated yam plantlets were morphotypes (LBVM01andLBVM02), inoculated separately with F. mosseae which were very dominant in fields or with G. dussii and also with 500 that cassava was used as a trap plant. vermiform Scutellonema bradys and These morphotypes were molecularly the plantlets grown for six additional identified as Acaulospora colombiana months in a greenhouse. Data revealed and Ambispora appendicula improved yam growth in the AMF respectively, using LSU-ITS-SSU treatments, with higher yields in the D. rRNA region, with the most abundant alata cultivars and also when compared species being A. colombiana. The to the non-arbuscular mycorrhizal cassava variety TME 7 ‘Yavo’ has the treatments. There was also a reduction in least egg and nematode densities in S. bradys densities on yam plantlets that treatments that received Acaulospora were pre-inoculated with AMF. There colombiana and Ambispora appendicula was generally higher colonization rates inoculations independently or both. by AMF on all cultivars inoculated Meloidogyne sp. control in with F. mosseae, compared to G. sweetpotato using AMF for improved dussii in treatments without S. bradys, plant growth is also possible (Gapasin, however, higher colonization rates of 1996). In this study, a nematicide AMF was noted on all yam cultivars (Nemacur) and AMF were utilized also inoculated with S. bradys, with the for enhanced plant growth and exception of the cultivar (TDa98-165) nematode control in sweetpotato. inoculated with G. dussii. Higher concentrations of AMF in plant Application of AMF to control roots resulted in lower nematodes and nematodes of cassava (Manihot galls in the roots. Although the least esculenta Crantz) has also been achieved nematode numbers and galls (1.60 and 398 Biocontrol of Meloidogyne spp. using Arbuscular mycorrhiza

10.20) were the least in the Nemacur- of concern (Ceballos et al., 2013). treated plants respectively, there were Additionally, tillage can be minimised no significant differences among these together with crop rotations and drastic values and those for the AMF-treated reduction of chemicals to preserve plants, an indication of the potential of these microbes. AMF in management of Meloidogyne In the development of inoculum, sp. in sweetpotato. the source of the AMF together with its chemical composition is very important Advantages in application (Berruti et al., 2016). The application of native compared to of native AMF strains to control root- commercial AMF for nematode management and knot nematode in pot experiments with yield of root and tuber crops tomato plants showed lower nematode Research scientists are making use numbers and less galling, compared of commercial inoculants which lack to the commercial product (Affokpon non-indigenous arbuscular mycorrhizal et al., 2011). A dis-advantage in the fungi (AMF) for crop improvement in application of commercial inoculants Africa because of their availability. applied as bi-control agents relates However, there are concerns about the to competition from native AMF application of foreign AMF strains in communities. The cost of the place of local strains for pathogenic commercial AMF strains may also be control (Plenchette et al., 2005; higher compared to those obtained Affokpon et al., 2011; Oliveira et al., from a local community (Plenchette et 2005; Schwartz et al., 2006). The al., 2005). There are studies to confirm identification and characterisation of the variable impacts of different AMF local microbes that can be used as bio- species plant growth and development control agents is therefore encouraged (van der Heijden et al., 1998; Bever et (Gosling et al., 2006; Koide et al., 1999). al., 2001; Vogelsang et al., 2006). Understanding these communities Mechanisms involved in through metagenomic and genetic bio-control of nematodes approaches is highly recommended Nutrient uptake (Rodriguez and Sanders, 2015). Arbuscular mycorrhizal fungi have the Furthermore, the need to understand potential to increase absorption of water whether new allelles may be introduced and mineral nutrients (phosphate and into a prevoius AMF community is nitrogen) for their host plant (Parniske, Biocontrol of Meloidogyne spp. using Arbuscular mycorrhiza 399

2008; Baum et al., 2015). There is also et al., 2014; Elsen et al., 2003a; Hewezi a possibility of some micro-elements and Baum, 2012). Mycorrhizal infected e.g., zinc which may also be absorbed plant roots usually have an increase in (Smith and Smith, 2011a,b). The AMF their branching abilities and this could also receives photosynthetic carbon either positively or negatively enhance from their host (Gianinazzi et al., 2010). pathogenic infections (Vos et al., 2014). There are propositions that a high Increase nutrient content in soils uptake of phosphate is a mechanism enhances root growth and branching, used by the AMF in biocontrol of in mycorrhizal plants (Orfanoudakis et micro-organisms, however, addition of al., 2010; Gutjahr and Paszkowski, 2013). phosphate to non-mycorrhizal plants Positive impacts on root vigor results never led to lower pathogenic infections in increased nutrient uptake in plants, (Bodker et al., 1998). This phenomenon which often eliminates infections from has been observed in tomato plants PPNs. This phenomenon has been that were colonised by Rhizophagus observed in banana fields infested with irregularis and infected with Alternaria Radopholus similis and Pratylenchus solani (Fritz et al., 2006). These plants coffeae (Migratory endo-parasites), and did not reveal symptoms caused by inoculated with AMF Funneliformis Alternaria solani and phosphate mosseae (Elsen et al., 2003a). The AMF absorbtion was absent, compared to enhanced branching of the banana roots. non-mycorrhizial plants. However, there are instances where an There could also be a reduction increase in root branching enhances in plant growth in mycorrhizal plants, the infection sites for PPNs and this although with an increase in phosphate depends on the zone of preference by the uptake (Smith and Smith, 2011a). nematode (Stoffelen et al., 2000; Elsen et Plants that are supplied with nutrients al., 2003b; Wyss, 2002; Curtis et al., 2009). tolerate high population densities of Radopholus similis move into their hosts plant-parasitic nematode in their roots through primary roots (Stoffelen et al., (Pettigrew et al., 2005). 2000; Elsen et al., 2003b). Root-knot and cyst nematodes, usually penetrate their Root morphology host roots through the elongation zones Root morphologies that are altered due and sites of lateral root formation, a to their colonisation by AMF serve as reason for this could be because of a a means of control against pathogenic high level of exudates released in these organisms, including nematodes (Vos zones (Wyss, 2002; Curtis et al., 2009). In a 400 Biocontrol of Meloidogyne spp. using Arbuscular mycorrhiza

study by Hewezi and Baum (2012), using exceptions exist to this hypothesis. An Arabidopsis thaliana plants infected established symbiosis between AMF with Heterodera schachtii juveniles, (Scutellospora heterogama) and sweet there were no significant differences in passion fruit (Passiflora alata) before the nematode numbers that penetrated M. incognita inoculation did not lead transgenic plant having either long or to lower reproduction levels of the short root lengths or those of the wild nematode, furthermore, co-inoculation types. of both pathogens had no bi-control influence on the plant (Dos Anjos et Nutrient and space al., 2010). However, in another study requirements co-inoculating native AMF together There is usually a competition for with a different nematode species space among AMF and PPNs or their (Meloidogyne exigua ) in coffee plants, interactions in roots of plants (Jung provided biocontrol (Alban et al., 2013). et al., 2012). Mycorrhizal arbuscules are formed in the cortex and these Root exudates reduce space requirements needed by Root exudates contain important PPNs during their feeding activities. chemicals e.g., organic acids, sugars Nematode species e.g., cyst nematode which are released by mycorrhizal whose feeding cells (syncytia) are and non-mycorrhizal plants (Sood, within the endodermis are less 2003; Lioussanne et al., 2008; Hage- influenced by the AMF. There is nutrient Ahmed et al., 2013). Other chemicals competition for carbon among the AMF include flavonoids (Steinkellner et and pathogen (Vos et al., 2014), and this al., 2007), amino acids (Harrier and carbon usually transferred from the Watson, 2004), phenolic compounds host is in a range of 4 to 20% (Hammer (McArthur and Knowles, 1992),) and et al., 2011). Various AMF species have strigolactone, a plant hormone (López- carbon sinks of varying strengths, and Ráez et al., 2011). Chemical compounds it could be hypothesised that, different that are released by the mycorrhizal AMF species will therefore have plants have a negative impact on the specific biocontrol levels (Lerat et al., nematode’s ability of penetrate roots 2003). There are theories that high (Vos et al., 2012a). AMF colonizations in roots should In a study by Vos et al. (2012 b,c), lead to high bio-control by the AMF Meloidogyne incognita juveniles were (Vierheilig et al., 2008). However, some unable to penetrate roots of tomato Biocontrol of Meloidogyne spp. using Arbuscular mycorrhiza 401

plants that had mycorrhizal symbiosis infections in roots and there are reports to with Funneliformis mosseae, however, confirm this (Fritz et al., 2006; Khaosaad high nematode numbers were obtained et al., 2007; Castellanos-Morales et al., from the control treatments which lacked 2011). A study by Elsen et al. (2008) the mycorrhizae. In-vitro chemotaxis to understand AMF-induced biocontrol bio-assay experiments provide against plant-parasitic nematodes in information on nematode movement Musa showed a systemic reduction of on media (Vos et al., 2012c). In this Radopholus similis and Pratylenchus study, Radopholus similis movements coffeae in a split – root experimental on media were limited in portions that design. Results revealed that Glomus received mycorrhizal root exudates. intraradices reduced about 50% of both These exudates vary depending in the nematode species in the treatments. AMF species and will therefore influence Beneficial microbes in the soil their control abilities (Kobra et al., rhizosphere are perceived as invaders, 2009). Microbial diversity in soils can be thereafter, an immune response is impacted by root exudates (Lioussanne, triggered, however the interaction leads 2010), and the presence of AMF in soils to effective colonization of host roots could lead to high facultative anaerobic in the later stages (Fig.1a) (Zamioudis bacteria, various Streptomyces species, and Pieterse, 2012). Immune signaling and actinomycetes (Scheublin et al., in the rhizosphere can be attributed to 2010; Miransari, 2011; Nuccio et molecules known as microbe-associated al., 2013). Root exudates obtained molecular patterns (MAMPs), these from mycorrhizal plants can attract molecules further induce MAMP- Pseudomonas fluorescens (Sood, 2003) triggered immunity (MTI) (Boller and and Trichoderma spp. (Filion et al., Felix 2009; Jones and Dangl 2006). 1999; Druzhinina et al., 2011) which Defense-and stress-related genes are up has biocontrol properties for nematode regulated in the early interaction stages management (Dong and Zhang, between plant and AMF, however as 2006; Sikora et al., 2008). the interaction proceeds, these genes are suppressed (Kapulnik et al., 1996). Symbiotic reprogramming Symbiotic re-programming occurs in in host cells plant cells after the mycorrhizal Myc Systemic signals transferred from factors come into play and the MTI is AMF to the non-infected portions of interrupted. roots play roles in reducing pathogenic The SP7 effector can be 402 Biocontrol of Meloidogyne spp. using Arbuscular mycorrhiza

associated with the AMF Glomus The MTI response occurring in the intraradices and is an important and early time points of AMF colonization the premier endomycorrhizal effector of plant roots may be described as weak identified with roles in defense and transient and the AMF is able to signalling (Kloppholz et al. 2011). The suppress the MTI response by effectors SP7 expression is activated in the host (Zamioudis and Pieterse, 2012). roots and transported into the plant Salicylic acid (SA) also has specific cytosol. A nuclear localization signal roles in the successful establishment (NLS) targets SP7 to the nucleus, and of a symbiotic program and the AMF there is an interaction with the defense- colonization is negatively influenced related ethylene (ET)-responsive factor by SA, leading to a suppression of the ERF19 leading to the ERF19-mediated SA-mediated defense response (Hause transcription being blocked (Fig. 1b). et al., 2007; Miransari et al., 2014).

B

Fig. 1. Model for the modulation of host recognize ectomycorrhizal (EMF) and immunity in ecto-mycorrhizal (EMF) arbuscular mycorrhizal (AMF) fungi as and arbuscular mycorrhizal (AMF) potential invaders; pattern recognition fungi.A) Root exudates recruit symbiotic receptors (PRR) in the host perceive mycorrhizal fungi and prime them for microbe-associated molecular patterns the interaction. Host plants initially (MAMPs, yellow-colored shapes) and Biocontrol of Meloidogyne spp. using Arbuscular mycorrhiza 403

a signaling cascade is initiated that crops. Application of AMF in root and results in MAMP-triggered immunity tuber cropping systems in Ghana is in (MTI). B) The establishment of the its infancy, and needs to be encouraged. symbiotic program in plant cells, which Country-wide surveys of soils are is activated upon perception of the needed to identify location specific mycorrhizal Myc factors, counteracts AMF strains, these need to be isolated MTI with mechanisms yet to be defined. and characterised both morphologically Molecules (brown-colored shapes) and molecularly and ultimately used in that are secreted in the apoplastic or nematode management for increased periarbuscular space (PAS) may act yields. Furthermore, the local strains can as either apoplastic or cytoplasmic be produced in commercial quantities effectors to suppress the MTI response and made available to farmers. or promote the symbiotic program. The AMF Glomus intraradices secretes the SP7 effector which is translocated into the plant cytosol; a nuclear localization signal (NLS) targets SP7 to the nucleus, where it interacts with the defense-related transcription factor ERF19 to block the ERF19-mediated transcriptional program. (Zamioudis and Pieterse, 2012).

Conclusions There is a demand for beneficial microbial inocula for large-scale field application for nematode control, and production of higher yields, and AMF has the potential of providing these benefits. Research into AMF-mediated biocontrol through system biology and genomic approaches will enhance further insights into the various complex mechanisms used by the AMF in nematode control in root and tuber 404 Biocontrol of Meloidogyne spp. using Arbuscular mycorrhiza

REFERENCES

Adegbite, A.A., Adesiyan, S.O., Adbaje, G.O., and Omoloye, A.A. (2005). Host suitability of crops under yam intercrop to root-knot nematode (M. incognita Race 2) in South-Western Nigeria. J. Agr. Rural Dev. Trop., 106: 113-118. Affokpon, A., Coyne, D.L., Lawouin, L., Tossou, C., Agbèdè, R. D., and Coosemans, J. (2011). Effectiveness of native West African arbuscular mycorrhizal fungi in protecting vegetable crops against root-knot nematodes. Biol. Fertil. Soils. 47:207–217.doi:10.1007/s00374-010-0525-1 Affokpon, A., Coyne, D.L., Lawouin, L., Tossou, C., Agbèdè, R.D., and Coosemans, J. (2011). Effectiveness of native West African arbuscular mycorrhizal fungi in protecting vegetable crops against root-knot nematodes. Biol. Fertil. Soils. 47:207–217.doi:10.1007/s00374-010-0525-1 Alban R., Guerrero R., Toro M. (2013). Interactions between a root-knot nematode (Meloidogyne exigua) and arbuscular mycorrhizae in coffee plant development (Coffea arabica). Am. J. Plant Sci. 4: 19–23. 10.4236/ajps.2013.47A2003 Angelard, C., Colard, A., Niculita-Hirzel, H., Croll, D., and Sanders, I.R. (2010). Segregation in a mycorrhizal fungus alters rice growth and symbiosis-specific gene transcription. Current Biology 20: 1216–1221. Araim, G., Saleem, A., Amason, J.T., and Charest, C. (2009). Root colonization by an arbuscular mycorrhizal (AM) fungus increases growth and secondary metabolism of purple coneflower, Echinacea purpurea (L.) Moench. Journal of Agricultural and Food Chemistry 57:2255–2258. DOI 10.1021/jf803173x. Augé, R.M., Toler, H.D., and Saxton, A.M. (2015). Arbuscular mycorrhizal symbiosis alters stomatal conductance of host plants more under drought than under amply watered conditions: ameta-analysis. Mycorrhiza 25:13–24. doi: 10.1007/s00572- 014-0585-4 Baum, C., El-Tohamy, W., and Gruda, N. (2015). Increasing the productivity and product quality of vegetable crops using arbuscular mycorrhizal fungi: are view. Sci. Hortic. (Amsterdam). 187: 131–141.doi:10.1016/j.scienta.2015.03.002 Berruti, A., Lumini, E., Balestrini, R., and Bianciotto, V. (2016). Arbuscular mycorrhizal fungi as natural biofertilizers: let’s benefit from past successes. Front. Microbiol. 6:1559. doi:10.3389/fmicb.2015.01559 Bever, J.D., Schultz, P.A., Pringle, A., and Morton, J.B. (2001). Arbuscular mycorrhizal Biocontrol of Meloidogyne spp. using Arbuscular mycorrhiza 405 fungi: More diverse than meets the eye, and the ecological tale of why. Bioscience 51: 923–931. Bodker, L., Kjoller, R., and Rosendahl, S. (1998). Effect of phosphate and the arbuscular mycorrhizal fungus Glomus intraradices on disease severity of root rot of peas (Pisum sativum) caused by Aphanomyces euteiches. Mycorrhiza 8:169–174. Boller, T., and Felix, G. 2009. A renaissance of elicitors: Perception of microbe- associated molecular patterns and danger signals by patternrecognition receptors. Annu. Rev. Plant Biol. 60:379-406. Burns, A., Gleadow, R., Cliff, J., Zacarias, A., and Cavagnaro, T. (2010). Cassava: The drought, war and famine crop in a changing world. Sustainability 2: 3572–3607. doi: 10.3390/su2113572 Cardoso, I.M., and Kuyper, T.W. (2006). Mycorrhizas and tropical soil fertility. Agric. Ecosyst. Environ. 116,72–84.doi:10.1016/j.agee.2006.03.011 Cassells, A.C. (2012). Pathogen and biological contamination management in plant tissue culture: phytopathogens, vitro pathogens, and vitro pests”. Methods Mol. Biol. 877: 57-80. Castellanos-Morales, V., Keiser, C., Cárdenas-Navarro, R., Grausgruber, H., Glauninger, J., García-Garrido, J. M., et al. (2011). The bioprotective effect of AM root colonization against the soil-borne fungal pathogen Gaeumannomyces graminis var. tritici in barley depends on the barley variety. Soil Biol. Biochem. 43: 831–834. 10.1016/j.soilbio.2010.12.020 Ceballos, I., Ruiz, M., Fernandez, C., Pena, R., Rodriguez, A., and Sanders, I.R. (2013). The invitro mass-produced model mycorrhizal fungus, Rhizophagus irregularis, significantly increases yields of the globally important food security crop Cassava. PLoSONE 8:e70633.doi:10.1371/journal.pone.0070633 Curtis, R., Robinson, A., and Perry, R. (2009). Hatch and host location. In: Root – knot nematodes, eds R. N. Perry., Moens, M., and Starr, J.L. (Wallingford: CAB International), 139–162. Davis Jr, F.T., Calderon, C.M., and Huaman, Z. (2005a). Influence of arbuscular mycorrhizae indigenous to Peru and a flavonoid on growth, yield, and leaf elemental concentration of ‘Yungay’ potatoes. HortScience 40: 381-385. Davis Jr, F.T., Calderon, C.M., Huaman, Z., and Gomez, R. (2005b). Influence of a flavonoid (formononetin) on mycorrhizal activity and potato crop productivity in the highlands of Peru. Sci. Hortic. 106: 318-329. Dong, L. Q., and Zhang, K.Q. (2006). Microbial control of plant-parasitic nematodes: a five-party interaction. Plant Soil 288: 31–45.doi:10.1007/s11104 – 006-9009-3 Dos Anjos, É.C.T., Cavalcante, U.M.T., Gonçalves, D.M.C., Pedrosa, E.M.R., dos Santos, V.F., and Maia, L.C. (2010). Interactions between an arbuscular 406 Biocontrol of Meloidogyne spp. using Arbuscular mycorrhiza mycorrhizal fungus (Scutellospora heterogama) and the root-knot nematode (Meloidogyne incognita) on sweet passion fruit (Passiflora alata). BrazilianArch. Biol. Technol. 53: 801–809.doi:10.1590/S1516-89132010000400008 Douds Jr, D.D, Nagahashi, G., Reider, C., and Hepperly, P.R. (2007). Inoculation with arbuscular mycorrhizal fungi increases the yield of potatoes in a high P soil. Biol. Agric. Hortic. 25: 67-78. Drissner, D., Kunze, G., Callewaert, N., Gehrig, P., Tamasloukht, M., Boller, T., Felix, G., Amrhein, N., and Bucher, M. (2007). Lyso-phosphatidylcholine is a signal in the arbuscular mycorrhizal symbiosis. Science 318: 265-268. Druzhinina, I.S., Seidl-Seiboth, V., Herrera-Estrella, A., Horwitz, B.A., Kenerley, C. M., Monte, E., et al. (2011). Trichoderma: the genomics of opportunistic success. Nat. Rev. Microbiol. 9: 749–759.doi:10.1038/nrmicro2637 Duffy, E.M., Cassells, A.C. (2000). The effect of inoculation of potato (Solanum tuberosum L.) microplants with arbuscular mycorrhizal fungi on tuber yield and tuber size distribution. Appl. Soil Ecol. 15: 137-144. Elsen, A., Baimey, H., Swennen, R., and DeWaele, D. (2003b). Relative mycorrhizal dependency and mycorrhiza-nematode interaction in banana cultivars (Musa spp.) differing in nematode susceptibility. Plant Soil 256: 303–313.doi: 10.1023/A: 1026150917522 Elsen, A., Beeterens, R., Swennen, R., and DeWaele, D. (2003a). Effects of an arbuscular mycorrhizal fungus and two plant-parasitic nematodes on Musa genotypes differing in root morphology. Biol. Fertil. Soils 38:367–376.doi: 10.1007/s00374- 003-0669-3 FAO (2013). Save and grow: Cassava a guide to sustainable production intensification. Rome: FAO. FAOSTAT, (2012). Faostat Agricultural Database-Agricultural Production Http://www. faostat.fao.org. FAOSTAT, (2013). Faostat Agricultural Database-Agricultural Production Http://www. faostat.fao.org Filion, M., St-Arnaud, M., Fortin, J. A. (1999). Direct interaction between the arbuscular mycorrhizal fungus Glomus intraradices and different rhizosphere microorganisms. New Phytol. 141: 525–533. 10.1046/j.1469-8137.1999.00366.x Fritz, M., Jakobsen, I., Lyngkjaer, M. F., Thordal-Christensen, H., and Pons – Kühnemann, J. (2006). Arbuscular mycorrhiza reduces susceptibility of tomato to Alternaria solani. Mycorrhiza 16: 413–9. doi: 10.1007/s00572 – 006-0051-z Gapasin, R.M. (1996). Vesicular-arbuscular mycorrhizal (VAM) fungi for the control of root-knot nematode (Meloidogyne incognita) in sweetpotato. (Visayas State Coll. of Agriculture, Baybay 6521-A, Leyte (Philippines) Biocontrol of Meloidogyne spp. using Arbuscular mycorrhiza 407

Gianinazzi, S., Gollotte, A., Binet, M.-N., vanTuinen, D., Redecker, D., andWipf, D. (2010). Agroecology: the key role of arbuscular mycorrhizas in ecosystem services. Mycorrhiza 20: 519–30. doi: 10.1007/s00572-010-0333-3 Gosling, P., Hodge, A., Goodlass, G., and Bending. G.D. (2006). Arbuscular mycorrhizal fungi and organic farming. Agric. Ecosyst. Environ. 113: 17-35. Gutjahr, C., and Paszkowski, U. (2013). Multiple control levels of root system remodeling in arbuscular mycorrhizal symbiosis. Front. Plant Sci. 4:204. doi: 10.3389/fpls.2013.00204 Hage-Ahmed, K., Moyses, A., Voglgruber, A., Hadacek, F., and Steinkellner, S. (2013). Alterations in root exudation of intercropped tomato mediated by the arbuscular mycorrhizal fungus Glomus mosseae and the soilborne pathogen Fusarium oxysporum f. sp. lycopersici. J. Phytopathol. 161: 763–773. doi:10.1111/jph.12130 Hammer, E.C., Pallon, J., Wallander, H., and Olsson, P.A. (2011). Tit for tat? A mycorrhizal fungus accumulates phosphorus under low plant carbon availability. FEMS Microbiol. Ecol. 76: 236–244.doi:10.1111/j.1574 – 6941.2011.01043.x Harrier, L.A., and Watson, C.A. (2004). The potential role of arbuscular mycorrhizal (AM) fungi in the bio-protection of plants against soil-borne pathogens in organic and/or other sustainable farming systems. Pest Manag. Sci. 60: 149–57.doi:10.1002/ps.820 Hause, B., Mrosk, C., Isayenkov, S., and Strack, D. (2007). Jasmonates in arbuscular mycorrhizal interactions. Phytochemistry 68:101-110. He, X.H., Critchley, C., and Bledsoe, C. (2003). Nitrogen transfer within and between plants through common mycorrhizal networks (CMNs). Crit. Rev. Plant Sci. 22:531–567.doi:10.1080/713608315 Hewezi, T., and Baum, T. (2012). Manipulation of plant cells by cyst and root-knot nematode effectors. Mol. Plant Microbe Interact. 26: 9–16.doi:10.1094/MPMI – 05-12-0106-FI International Institute of Tropical Agriculture (IITA) “Annual Report”, Ibadan, Nigeria, 2006. Jones, J.D.G., and Dangl, J.L. 2006. The plant immune system. Nature 444: 323–329. 10.1038/nature05286 Jung, S.C., Martinez-Medina, A., Lopez-Raez, J.A., and Pozo, M.J. 2012. Mycorrhiza- induced resistance and priming of plant defenses. J. Chem. Ecol. 38: 651–664. doi: 10.1007/s10886-012-0134-6 Kapulnik, Y., Volpin, H., Itzhaki, H., Ganon, D., Galili, S., David, R., Shaul, O., Elad, Y., Chet, I., and Okon, Y. 1996. Suppression of defence responses in mycorrhizal alfalfa and roots. New Phytol. 133:59-64. Khaosaad, T., García-Garrido, J. M., Steinkellner, S., Vierheilig, H. 2007. Take-all 408 Biocontrol of Meloidogyne spp. using Arbuscular mycorrhiza

disease is systemically reduced in roots of mycorrhizal barley plants. Soil Biol. Biochem. 39: 727–734. 10.1016/j.soilbio.2006.09.014 Kloppholz, S., Kuhn, H., and Requena, N. (2011). A secreted fungal effector of Glomus intraradices promotes symbiotic biotrophy. Curr. Biol. 21:1204-1209. Kobra, N., Jalil, K., Youbert, G. (2009). Effects of three Glomus species as biocontrol agents against Verticillium-induced wilt in cotton. J. Plant Prot. Res. 49: 185–189. 10.2478/v10045-009-0027-z Koide, R.T., Landherr, L.L., Besmer, Y.L, Detweiler, J.M., and Holcomb, E.J. (1999). Strategies for mycorrhizal inoculation of six annual bedding plant species. HortScience 34: 1217-1220. Lerat, S., Lapointe, L., Piché, Y., and Vierheilig, H. (2003). Strains colonizing barley roots. Can. J. Bot. 81: 886–889.doi:10.1139/b03-070 Lioussanne, L. (2010). Review.The role of the arbuscular mycorrhiza-associated rhizobacteria in the biocontrol of soilborne phyto-pathogens. Spanish J.Agric. Res. 8: 3–5. doi:10.5424/sjar/201008S1-5301 Lioussanne, L., Jolicoeur, M., St-Arnaud, M. (2008). Mycorrhizal colonization with Glomus intraradices and development stage of transformed tomato roots significantly modify the chemotactic response of zoospores of the pathogen Phytophthora nicotianae. Soil Biol. Biochem. 40: 2217–2224. 10.1016/j. soilbio.2008.04.013 López-Ráez, J.A., Charnikhova, T., Fernández, I., Bouwmeester, H., and Pozo, M.J. (2011). Arbuscular mycorrhizal symbiosis decreases strigolactone production in tomato. J. Plant Physiol. 168:294–297.doi:10.1016/j.jplph.2010. 08.011 Lu, F.C., Lee, C.Y. and Wang, C.L. (2015). The influence of arbuscular mycorrhizal fungi inoculation on yam (Dioscorea spp.) tuber weights and secondary metabolite content. Peer J., 3: e1266 Mathur, N., and Vyas, A. (1995). Influence of VA mycorrhizae on net photosynthesis and transpiration of Ziziphus mauritiana. J. Plant Physiol. 147: 328–330.doi:10.1016/ S0176-1617 (11)82161-9 McArthur, D.A., and Knowles, N.R. (1992). Resistance responses of potatoto vesicular- arbuscular mycorrhizal fungi under varying abiotic phosphorus levels. Plant Physiol. 100: 341–351. doi:10.1104/pp.100.1.341 McArthur, D.A.J., Knowles, N.R. (1993). Influence of species of vesicular-arbuscular mycorrhizal fungi and phosphorus nutrition on growth, development, and mineral nutrition of potato (Solanum tuberosum L.). Plant Physiol. 102: 771-782. Miransari, M. 2011.Interactions between arbuscular mycorrhizal fungi and soil bacteria. Appl. Microbiol. Biotechnol. 89: 917–930.doi:10.1007/s00253-010 – 3004-6 Biocontrol of Meloidogyne spp. using Arbuscular mycorrhiza 409

Miransari, M., Abrishamchi, A., Khoshbakht, K., and Niknam, V. (2014). Plant hormones as signals in arbuscular mycorrhizal symbiosis. Crit. Rev. Biotechnol. 8551: 1–12. 10.3109/07388551.2012.731684 Nuccio, E.E., Hodge, A., Pett-Ridge, J., Herman, D.J., Weber, P.K., and Firestone, M. K. (2013). An arbuscular mycorrhizal fungus significantly modifies the soil bacterial community and nitrogen cycling during litter decomposition. Environ. Microbiol. 15: 1870–1881. doi:10.1111/1462-2920.12081 Oliveira, R. S., Vosatka, M., Dodd, J. C., and Castro, P. M. (2005). Studies on the diversity of arbuscular mycorrhizal fungi and the efficacy of two native isolates in a highly alkaline anthropogenic sediment. Mycorrhiza 16: 23–31.doi:10.1007/s00572-005- 0010-0 Orfanoudakis, M., Wheeler, C.T., and Hooker, J.E. (2010). Both the arbuscular mycorrhizal fungus Gigaspora rosea and Frankia increase root system branching and reduce root hair frequency in Alnus glutinosa. Mycorrhiza 20:117–126.doi: 10.1007/s00572-009-0271-0 Osei, K., Awuah, R.T., Tabil, M. A., and Asante, J.S. (2004). Prevalence and farmers’ perceptions of parasitic nematodes in yam rhizosphere soils from some yam producing areas of Ghana. Agricultural and Food Science Journal of Ghana 3:217-226. Parniske, M. (2008). Arbuscular mycorrhiza: the mother of plant root endosymbioses. Nat. Rev. Microbiol. 6:763–775.doi:10.1038/nrmicro1987 Pettigrew, W.T., Meredith, W.R., and Young, L.D. (2005). Potassium fertilization effects on cotton lint yield, yield components, and reniform nematode populations. Agron. J. 97: 1245–1251. doi:10.2134/agronj2004.0321 Plenchette, C., Clermont-dauphin, C., Meynard, J.M., and Fortin, J. A. (2005). Managing arbuscular mycorrhizal fungi in cropping systems. Can. J. Plant Sci. 85:31–40. Porcel, R., Aroca, R., and Ruiz-Lozano, J.M. (2011).Salinity stress alleviation using arbuscular mycorrhizal fungi. A review. Agron. Sustain. Dev. 32:181–200. doi:10.1007/s13593-011-0029-x Pozo, M.J., and Azcón-Aguilar, C. (2007). Unraveling mycorrhiza-induced resistance. Curr. Opin. Plant Biol. 10:393–398.doi:10.1016/j.pbi.2007.05.00 Raquena, N., Serrano, E., Ocόn, A., and Breuninger, M. (2007). Plant signals and fungal perception during arbuscular mycorrhiza establishment. Phytochemistry 68: 33- 40. Rodriguez, A., and Sanders, I.R. (2015). The role of community and population ecology in applying mycorrhizal fungi for improved food security. ISMEJ. 9: 1053–1061. doi:10.1038/ismej.2014.207 410 Biocontrol of Meloidogyne spp. using Arbuscular mycorrhiza

Scheublin, T.R., Sanders, I.R., Keel, C., and van der Meer, J.R. (2010). Characterisation of microbial communities colonising the hyphal surfaces of arbuscular mycorrhizal fungi. ISMEJ. 4:752–763.doi:10.1038/ismej. 2010.5 Schüßler, A.H., Gehrig, H., Schwarzott, D., and Walker, C. (2001). Analysis of partial Glomales SSU rRNA gene sequences: implications for primer design and phylogeny. Mycol. Res. 105: 5–15.doi:10.1017/S0953756200003725 Schwartz, M.W., Hoeksema, J.D., Gehring, C.A., Klironomos, J.N., Johnson, N.C, et al. (2006). The promise and the potential consequences of the global transport of mycorrhizal fungal inoculum. Ecol Lett 9: 501–515. Séry, D.J-M., Kouadjo, Z.G.C., Voko, B.R.R., and Zézé, A. (2016). Selecting native arbuscular mycorrhizal fungi to promote cassava growth and increase yield under field conditions. Front. Microbiol. 7:2063. doi: 10.3389/fmicb.2016.02063 Sieverding, E. (1989). Ecology of VAM fungi in tropical agrosystems. Agricult. Ecosys. Environ. 29:369–390. Sikora, R.A., Pocasangre, L., FeldeZum, A., Niere, B., Vu, T.T., and Dababat, A.A. (2008). Mutualistic endophytic fungi and in planta suppressiveness to plant-parasitic nematodes. Biol. Control 46:15–23.doi: 10.1016/j. biocontrol.2008.02.011 Smith, F.A., and Smith, S.E. (2011a). What is the significance of the arbuscular mycorrhizal colonisation of many economically important crop plants? Plant Soil 348: 63–79. doi: 10.1007/s11104-011-0865-0 Smith, S.E., and Read, D.J. (2008). Mineral nutrition, toxic element accumulation and water relations of arbuscular mycorrhizal plants. In: Mycorrhizal symbiosis, 3rd Ed.S.E. Smith and Read, D.J. (London: Academic Press): 145–148. Smith, S.E., and Smith, F.A. (2011b). Roles of arbuscular mycorrhizas in plant nutrition and growth: new paradigms from cellular to ecosystem scales. Annu. Rev.Plant Biol. 62: 227–250.doi:10.1146/annurev-arplant-042110-103846 Sood, G. S. (2003). Chemotactic response of plant-growth-promoting bacteria towards roots of vesicular-arbuscular mycorrhizal tomato plants. FEMS Microbiol. Ecol. 45: 219–227. doi: 10.1016/S0168-6496(03)00155-7 Steinkellner, S., Lendzemo, V., Langer, I., Schweiger, P., Khaosaad, T., Toussaint, J.P., and Vierheilig, H. 2007. Flavonoids and strigolactones in root exudates as signals in symbiotic and pathogenic plant-fungus interactions. Molecules 12: 1290-1306. Steinkellner, S., Lendzemo, V., Langer, I., Schweiger, P., Khaosaad, T., Toussaint, J.- P., etal. (2007). Flavonoids and strigolactones in root exudates as signals in symbiotic and pathogenic plant-fungus interactions. Molecules 12: 1290–1306. doi: 10.3390/12071290 Stoffelen, R., Verlinden, R., Xuyen, N.T., DeWaele, D., and Swennen, R. (2000). Biocontrol of Meloidogyne spp. using Arbuscular mycorrhiza 411

Host plant response of Eumusa and Australimusa bananas (Musa spp.) to migratory endo-parasitic and root-knot nematodes. Nematology 2: 907–916.doi: 10.1163/156854100750112851 Tchabi, A., Hountondji, F.C.C., Ogunsola, B., Lawouin, L., Coyne, D., Wiemken, A., and Oehl, F. (2016). The influence of arbuscular mycorrhizal fungi inoculation on micro-propagated hybrid yam (Dioscorea spp.) growth and root knot nematode (Meloidogyne spp.) suppression. Int. J. Curr. Microbiol. App. Sci 5(10): 267-281. Toussaint, J.P., Smith, F.A, and Smith, S.E. (2007). Arbuscular mycorrhizal fungi can induce the production of phytochemicals in sweet basil irrespective of phosphorus nutrition. Mycorrhiza 17:291–297 DOI 10.1007/s00572-006-0104-3. van der Heijden M.G.A., Boller, T., Wiemken, A. & Sanders, I.R. (1998). Different arbuscular mycorrhizal fungal species are potential determinants of plant community structure. Ecology 79: 2082–2091. Vierheilig, H., Steinkellner, S., and Khaosaad, T. (2008). The bio-control effect of mycorrhization on soil borne fungal pathogens and the autoregulation of the AM symbiosis: one mechanism, two effects? In: Mycorrhiza, ed. Varma, A. (Berlin: Springer-Verlag), 307–320.doi:10.1007/978-3-540-78826-3_15 Vogelsang, K.M., Reynolds, H.L., and Bever, J.D. (2006.) Mycorrhizal fungal identity and richness determine the diversity and productivity of a tallgrass prairie system. New Phytol 172: 554–562. Vos, C. M., Tesfahun, A. N., Panis, B., De Waele, D., Elsen, A. (2012a). Arbuscular mycorrhizal fungi induce systemic resistance in tomato against the sedentary nematode Meloidogyne incognita and the migratory nematode Pratylenchus penetrans. Appl. Soil Ecol. 61: 1–6. 10.1016/j.apsoil.2012.04.007 Vos, C., Claerhout, S., Mkandawire, R., Panis, B., de Waele, D., Elsen, A. (2012b). Arbuscular mycorrhizal fungi reduce root-knot nematode penetration through altered root exudation of their host. Plant Soil 354: 335–345. 10.1007/ s11104-011-1070-x Vos, C., Van Den Broucke, D., Lombi, F. M., De Waele, D., Elsen, A. (2012c). Mycorrhiza-induced resistance in banana acts on nematode host location and penetration. Soil Biol. Biochem. 47: 60–66. 10.1016/j.soilbio.2011.12.027 Vos, C.M., Yang, Y., DeConinck, B., and Cammue, B.P.A. (2014). Fungal-like bio-control organisms in tomato disease control. Biol. Control 74: 65–81.doi: 10.1016/j. biocontrol.2014.04.004 Vosatka, M., and Gryndler, M. (2000). Response of micropropagated potatoes transplanted to peat media to post-vitro inoculation with arbuscular mycorrhizal fungi and soil bacteria. Appl. Soil Ecol. 15: 145-152. Wyss, U. (2002). Feeding behaviour of plant-parasitic nematodes. In: Biology of 412 Biocontrol of Meloidogyne spp. using Arbuscular mycorrhiza

nematodes, ed. Lee, D.L. (London: Taylor & Francis), 233–259. Yaghoub, R., andWeria, W. (2013). Arbuscular mycorrhizal fungi associated with some aromatic and medicinal plants. Bulletin of Environment, Pharmacology and Life Sciences 2(11):129–138. Zamioudis, C., and Pieterse, C. M. J. (2012). Modulation of host immunity by beneficial microbes. Mol. Plant Microbe Interact. 25: 139–150. 10.1094/MPMI-06-11-0179 413

Mechanisation of Cassava (Root and Tuber Crops) Production in Ghana

Prof. Emmanuel Y.H. Bobobee, PhD Department of Agricultural & Biosystems Engineering Kwame Nkrumah University of Science and Technology (KNUST) Kumasi, Ghana E-mail: [email protected]

Abstract agriculture. Apart from using tractors Cassava (Manihot esculenta. Crantz), for primary tillage operations and to a yam (Dioscorea spp), cocoyam small extent secondary tillage to break (Colocasia esculenta) and sweet potato the big clods, most smallholder farmers (Ipomea batatas) are important food depend on manual labour for their security, industrial and energy crops agricultural activities. The predominant in Ghana. Their roots provide dietary use of labour intensive manual tools for carbohydrates for millions of Ghanaians, farming activities makes agriculture with consumption exceeding 148 kg per a way of life and unattractive as a capita in the case of cassava. Cassava business venture. Only few farmers alone contributes 22% to the nation’s practice conservation agriculture with agricultural gross domestic product. cassava and cocoyam while majority National cassava production in 2015 of smallholder farmers employ tractor was nearly 16 million tonnes on over services or conventional methods to one million hectares, making Ghana the plough and harrow before planting. third leading producer in Africa after The traditional random or haphazard Nigeria and DR Congo, and the sixth planting is another major constraint to in the world. However, apart from yam, modernise and mechanise production Ghana’s share of the global cassava and harvesting of root crop production export market is negligible. One main in Ghana. Manual root crop harvesting is challenge hindering the modernization a painful, stressful and time consuming and mechanisation of root and tuber activity especially, during the dry production in Ghana is the low level of season. Root crop harvesting with mechanisation technology inputs into 414 Mechanisation of Cassava (Root and Tuber Crops)

manual tools is done in squatting or forces of 10-15 kN that are within the stooping position. Until recently, there draught capability of existing tractors are no commercial mechanical root crop available with smallholder farmers on harvesters produced in Africa for use the continent. The harvester has no by root crop growers on the continent. moving parts, is robust, durable and This makes root crop production to easy to maintain. The only replaceable be full of drudgery, unattractive to the part is the reversible digging blade that youth and dependent on aging farmers, wears after harvesting several hectares. who produce limited outputs with little The harvester harvests one plant/second industrial and export potential. To compared with 5-10 mins/plant by provide a solution to that knowledge manual harvesting. This translates into gap, the Department of Agricultural and a work rate of harvesting one hectare in Biosystems Engineering of the Kwame two hours by one tractor operator and a Nkrumah University of Science and team of few workers, compared with 64- Technology (KNUST) has developed 104 manual harvesters per hectare per a device to harvest cassava and other day. The huge savings involved in using tuber crops mechanically to unlock the the harvester makes the investment in huge potential of these crops for industry the technology, economical and user and export in addition to their food friendly. This calls for awareness security status. This chapter discusses creation for its widespread adoption the challenges and opportunities for in Ghana and Africa. Depending on mechanised production of root and operator experience, tuber damage tuber crops from seedbed preparation could be lower than manual harvesting. to the introduction of a high speed To comply with mechanical harvesting mechanical cassava harvester invented and climate change adaptation at KNUST and evaluated in Ghana and strategies, it is recommended to plant South Africa for large-scale harvesting cassava on ridges spaced wide apart to of cassava, yam, potato and other tuber accommodate the tractor’s track width, crops. The TEK Mechanical Cassava while reducing intra-row distance Harvester (TEK MCH), a tractor- to attain optimum plant population drawn implement is light and does density. not require any dedicated high power- Keywords: cassava, aging farmers, rated tractors. The harvester, which is drudgery, mechanisation, mechanical one-metre wide penetrates to depths harvester, ridges, climate change. of 25-39 cm and develops resistance Mechanisation of Cassava (Root and Tuber Crops) 415

INTRODUCTION mainly for home consumption and the Cassava (Manihot esculenta Crantz) local markets. The competitiveness of is an important source of carbohydrate African cassava value chain products for urban and rural consumers in Sub- at the world market is low because the Saharan Africa. Cassava is a basic staple crop is produced and processed for food in Nigeria, Mozambique, Zambia, subsistence and not for commercial use. Democratic Republic of Congo (DRC), Public sector efforts to commercialise Ghana, Malawi, and Tanzania. Cassava cassava have also not been effective. is increasingly gaining importance as One main challenge is that market a cash crop for smallholder farmers opportunities for cassava in Africa are in the region. The demand is rising limited compared to other cassava- for cassava products such as cassava producing regions of the world. It has cake, high quality cassava flour, starch, been established that where cassava glucose, chips and others across Africa farmers have access to markets, they due to the drought tolerant nature tend to adopt productivity-enhancing of cassava and the increase in grain technologies. One of the key constraints prices. Despite the fact that yields are to cassava production in Africa is the lowest on the continent (10 tonnes lack of mechanisation or appropriate per hectare compared to 26 tonnes per production and processing tools. As hectare in India, Africa is the leading shown in Table 1. (Nweke et al., 2001), cassava producing region in the world, it takes 173 – 222 man days per hectare accounting for over 56% of global to produce cassava in Africa, with the production in 2012 (FAOSTAT, 2013). greatest labour demands recorded for About 93 percent of the Africa produce manual land clearing and harvesting. is consumed as food in contrast to Latin The growing market demand for cassava America and Asia, where less than half is calls for increased production through utilised for food consumption. Millions mechanisation to generate increased of African farmers grow cassava benefits for the millions of smallholder cassava farmers on the continent. 416 Mechanisation of Cassava (Root and Tuber Crops)

Table 1. Cassava production by task and days per ha in the Congo, Côte d’lvoire, Gha- na, Nigeria, Tanzania and Uganda

Task DR Congo Ghana Nigeria Tanzania Uganda

Land clearing 66 53 49 54 45

Seed-bed preparation 21 29 41 27 31

Planting 39 22 32 27 28

Weeding 27 28 38 28 32

Harvesting 48 44 62 46 52

Total days 201 173 222 182 187

Source: Nweke et al., (2001)

Objective AGRONOMIC REQUIREMENTS The main objective of the chapter is AT SEEDBED PREPARATION to report the mechanisation of cassava AND PLANTING production including harvesting of Production practices associated with cassava and other tuber crops. Specific cassava and other tuber crops may objectives are: include; land preparation, planting a) To determine the appropriate materials preparation, planting, agronomic requirements including soil fertilizer application, farm sanitation physical parameters during seedbed and weeding, pest and diseases control, preparation that support mechanisation, harvesting and processing. b) To determine operational Land Preparation parameters such as fuel consumption, Field is usually prepared after the implement draught forces, wheel slip, land has been cleared of trees, stumps during seedbed preparation and at and other hidden obstructions before harvest, ploughing followed by harrowing. c) To compare drudgery and tuber Cassava and other tuber crops could be damage in cassava harvesting using planted on the flat, ridges or on mounds manual and mechanical techniques as shown in Figure 1 after Ekanayake et al., (1997). Mechanisation of Cassava (Root and Tuber Crops) 417

Figure 1: Various landforms used for planting cassava. (Source: Ekanayake et al, 1997) Where ridges are preferred, they Information Service, 2005). According are constructed using a ridger after to Ennin et al., (2009) planting cassava harrowing and may range from 15- on ridges had the advantage of higher 30 cm in height and spaced 1.2 to 1.5 cassava root yield, better and easier meters or wide enough to accommodate field management and the potential the track width of the tractor pulling the for mechanization to further decrease harvester to avoid tractor tyres running drudgery and increase the scale of on adjacent cassava rows/ridges so as production compared with planting on to reduce damage of the unharvested the flat or on mounds. tubers as shown in Figures 2, 3, 4, 5, 6 & 7. The planting of cassava and other tuber crops on ridges is recommended not necessarily for yield impact but to serve as a guide for the tractor operator during the harvesting. The ridging technology is recommended, especially for mechanised production, since in the case of cassava, mature stems do not grow in straight lines. The ridge planting method could be done before or after planting and is reported to be more suitable in heavy soils or on light grey and sandy soils that are low in soil moisture and suitable for areas with drainage problems (International Starch Institute, 2002; Philippine Root Crops 418 Mechanisation of Cassava (Root and Tuber Crops)

Fig. 2. Ridge formation to comply with mechanised root and tuber crops production and harvesting.

Planting material selection Setts should be bundled and dipped and treatment in a fungicide/insecticide solution for Planting materials for cassava is 10-15 minutes and allowed to drain obtained as stem cuttings from off before planting. Fresh cassava stem vigorously growing plants 8 – 15 is identified if the latex or sap comes months old. It is advisable to select out within few seconds after cutting. fresh, mature, healthy and disease free Mature stem is identified if the diameter planting materials. Where planting of the pitch or cork is not more than half materials are readily available, cuttings the diameter of the cortex. Healthy stem with an average of 20-25 cm with 5 should be pest free and the diameter or more nodes are to be selected from not less than 1.5cm. Stalks are usually the middle stem portions. In times of kept for not more than five days, under planting material scarcity, single or shade in upright position in order to double node cuttings could be nursed give a higher chance of sprouting after and transplanted. Cutting of the stems planting. into setts or stakes is usually done with a sharp cuttings edges making sure the Planting stakes are handled carefully to avoid Cassava stem cuttings (also referred damage to the nodes (Philippine Root to as ‘stakes’) are planted 50 cm to Crops Information Service, 2005). 100 cm apart on the ridge at a 45o Mechanisation of Cassava (Root and Tuber Crops) 419

angle leaving 2-3 nodes above ground. vertical or slanting position to a depth Cassava is normally planted when of 5 – 10 cm depending on soil type there is sufficient moisture to promote and condition (International Starch spouting. From Fig. 3, stakes could be Institute, 2002). planted one per hole in a horizontal,

Figure 3: Different cassava planting positions after International Starch Institute, (2002). Planting is mostly done by hand in a come in single, double and multiple slanting position at an angle of 45o rows. when the soil is fairly dry to promote the formation of compactly arranged roots. Planting in a horizontal position is necessary when the soil is dry to increase stem production and in vertical position when done during the wet season to produce deeper lying storage roots for anchorage. In vertical or slant planting, at least two-thirds of the cutting length is buried or covered with soil (Philippine Root Crops Information Service, 2005). There are few mechanical cassava planters in use by some commercial farmers (fig.4) to reduce labour inputs, but yam and potato planters are not popular in Ghana. These mechanical planters 420 Mechanisation of Cassava (Root and Tuber Crops)

Fig. 4. A two-row mechanical cassava planter Recommended cassava population be wide apart to accommodate the density is approximately 10,000 tractor’s track width to comply with plants/ha depending on the cultivar. mechanical weeding and harvesting. Cuttings planted in moist soil under Figures 5, 6 &7 are planting layouts favourable conditions produce sprouts for high-speed mechanical cassava and adventitious roots within a week. harvesting operations. Recommended cassava ridges should

Fig.5. Cassava planted on ridges spaced to accommodate the tractor track width Mechanisation of Cassava (Root and Tuber Crops) 421

Observing the polarity of the nodes is with healthy planting material. Filling- essential in successful establishment of in or re-planting can be done two weeks the cuttings. The top of the cutting must after planting to replace dead stem be placed up with nodes also pointing cuttings or those which could not sprout upwards. Expected sprouting is 100% (International Starch Institute, 2002).

Fig.6. Cassava experimental plot at KNUST planted on ridges. The ridges are also conservation of growth. Hand-weeding using hoes and agricultural practices. When cassava machetes are normally recommended is planted on the flat and the field is after 3 months. If necessary, the enlarged flooded, there is a high possibility of crop canopy should limit weed growth the tubers getting rotten. When planted after 3 months (Melifonwu et al.2000). on ridges, the excess rainfall will be Many different types of weeds occur in evacuated through the furrows into cassava farms and cause considerable drains. In times of low precipitation, losses to the farmer. This is because the little moisture will accumulate in weeds compete with the cassava crop the furrows to reach the root zones. for nutrients, sunlight, and space. Weeds may harbour pests and diseases Weed, Pest and or physically injure cassava plants Disease Control and storage roots. Weeds occurring During the vegetative stage, the use of a in cassava farms can be put into three contact and/or pre – emergent herbicide main groups, namely, grasses, sedges, controls weeds for the first three months and broadleaf weeds (Melifonwu et al, 422 Mechanisation of Cassava (Root and Tuber Crops)

2000). Like many other crops grown germination of weeds. Pre-emergence in the tropics, cassava is susceptible to herbicides are also very effective to early weed competition. Slow initial control weeds in cassava (International development of sprouts from cassava Starch Institute, 2002). cuttings makes all cassava cultivars The major pests and diseases of susceptible to weed interference cassava are Thrips and Mites, which can during the first 3 to 4 months after be controlled using a recommended planting. Crop losses due to weeds miticides and insect growth regulators. can be as high as 50–70% depending These pests are prevalent during on the type of weed and duration of dry periods and decreases as rainfall competition (IITA, 2004). Weed control increases. Others are Cassava Shoot Fly, methods mostly employed are manual, Chinch bugs, Cassava Bacterial Blight, mechanical, agronomic and chemical. Rust and Super Elongation Disease. The manual method (using hoes and Control includes the use of systemic machetes) is effective when the farm insecticides during heavy infestations. size is small, and it is the most widely Crotalaria can be used as a trap crop used method by smallholder farmers for this bug as well as crop rotation in Ghana. Weeding is recommended at practices which break the life cycle of 4-5 weeks after planting and at 8 weeks the Chinch bugs. after planting until crop ground cover is Various pest and diseases attack complete (International Starch Institute, cassava, such as the mealybug, green 2002). According to Muma (2000) and mite, mosaic disease and the bacterial Nweke et al., (2001), weeding alone blight. The biological control method may require 27 to 38 man-days per has been used to bring the mealybug hectare. Hand picking of weeds and spot under control while the biological weeding 3-4 weeks after planting is also control of the green mite is still in advisable to effectively control weeds progress (Herren et al., 1987 and (Philippine Root Crops Information IFAD and FAO, 2005). The most Service, 2005). Mechanical weeding promising method of controlling the is also possible at the very start using mosaic disease and the bacterial blight an inter-row cultivator, spring tine is breeding resistant varieties, which cultivator or ridger. Weeds are however, involves a long and painstaking process best controlled through a proper crop of breeding and diffusion. Meanwhile, rotation scheme and with proper the green mite, mosaic disease and the pre-planting cultivation to prevent bacterial blight continue to cause yield Mechanisation of Cassava (Root and Tuber Crops) 423

losses in various parts of Africa (Kuiper status in Ghana, it is now being grown et al, 2007; IITA, 2004). Smallholder on large scale, repeatedly season after African farmers usually do not attempt season, on the same piece of land. to control the cassava pests and diseases Under this condition, the fertility of the with pesticides because of the limited soil and crop yields decline over time access to chemicals and because it is (El-Sharkawy and Cadavid, 2000). not economically profitable to apply According to Gutteridge and Shelton pesticides on cassava (IFAD and (1994), loss of soil fertility is especially FAO, 2005). However, farmers use serious in tropical regions, where the the following agronomic practices to soil lacks adequate plant nutrients and achieve partial control of the cassava organic matter due to leaching and pests and diseases; land rotation, crop erosion of vulnerable topsoil by intense rotation and selection of the pests rainfall. and diseases-resistant local varieties Philippine Root Crops Information (Philippine Root Crops Information Service (2005) suggested that ideally, Service, 2005; IITA, 2004). Improved soil analysis should be carried out prior quarantine inspection is needed to to planting to determine the kind of prevent, as much as possible, further fertilizer needed. However, the general introduction of new problems. There is recommendation for soils which have a need for better preparedness to control not been analyzed is 400kg/ha of new problems before they spread and complete (14 – 14-14) fertilizer, which take root in Africa (IFAD and FAO, is usually applied from 2-6 weeks after 2005). planting at 5-10 cm depth and 15-20cm away from the plant. Moreover, the Fertilizer Application use of compost or organic fertilizer Cassava root removes substantial is highly recommended. Cassava is amounts of nutrients from the soil, the noted to produce a crop with minimal highest being Potassium (K), followed inputs (Howeler et al, 2008). However, by Nitrogen (N), Calcium (Ca), optimal yields are recorded from fields Magnesium (Mg) and Phosphorus (P). with average soil fertility levels for food Adequate K is very important for starch crop production and regular moisture synthesis and translocation and increases availability (Kuiper et al, 2007). the plant’s resistance to anthracnose (El- A soil test should always be done Sharkawy and Cadavid, 2000). As the to determine soil fertility status and crop is gradually assuming an industrial fertilizer types and rates. When 424 Mechanisation of Cassava (Root and Tuber Crops)

soil tests are not done, a general with 11.77 t ha-1, an increase of 48.8% recommendation for fertilizing cassava when inorganic fertilizer was applied could be obtained from agronomists (Ayoola and Makinde 2007). or mixtures of single fertilizers such Even though cassava contributes as Calcium Nitrate, Muriate of Potash greatly to the Agricultural Gross and Triple Super Phosphate at 16 Domestic Project (AGDP) of Ghana weeks after planting, or applied at six (GTZ and Stumpf, 1998), the and 16 weeks after planting. Average application of fertilizer in its production quantities of fertilizer per plant at each is very minimal (FAO and IFAD, 2000). application work out to be one handful According to FAO (2013), some of the 85gm-113gm. Place fertilizers 15cm reasons were that farmers generally to 45cm from the base of the stem in believe that fertilizers reduce the quality drill holes to be 10cm to 15cm in depth of cassava tubers, cooking quality and to reduce fertilizer loss through runoff storage. This makes it difficult for them water. Applying fertilizer 16 weeks to adopt the use of fertilizers in cassava after planting enhances tuber bulking. productions. Again, because of the Research reports indicate cassava inherent capacity of cassava to produce has the ability to grow in poor soils and reasonable yields under adverse edaphic usually without any inputs while giving and climatic conditions, increasingly reasonable yields for food production. more marginal lands are being used for To be cultivated on a commercial its production without the application scale, cassava is very demanding in of any fertilizer (El-Sharkawy, 2000). nutrients and responds readily to the In cassava producing countries, better use of fertilizers. The application of soils are always devoted to more supplementary nutrients is therefore profitable crops, leaving those areas a sure means by which the fertility of with soil problems (i.e. high Al content, the soil could be sustained to ensure low exchangeable base content, high P continuous cropping of cassava to fixation, various degrees of erosion) increase yield of cassava production for cassava cultivation (Howeler, 2008, on the same piece of land. Fertilizer is Molina and El – Sharkawy, 1995). only applied during the first few months The low yields of cassava achieved of growth (O’Hair, 1995; Kuiper et al, in these poor soils are considered 2007) In situations where no fertilizer acceptable since most crops do not was applied, average yield of cassava perform well there. Moreover, cassava was very low (7.91 t ha-1) compared is a marginalized crop in food policy Mechanisation of Cassava (Root and Tuber Crops) 425

debates and burdened with the stigma too long in the soil, the central portion of being an inferior food, ill-suited becomes woody and inedible (USDA and uncompetitive with the glamour and NRCS, 2003). It also ties the crops such as imported rice and wheat land unnecessarily to one crop whilst because of several long-standing exposing the roots to pests. Cassava is myths and half-truths. Many food ready for harvest as soon as the storage policy analysts consider cassava as an roots are large enough to meet the inferior food because it is assumed that requirements of the consumer, starting its per capita consumption will decline from 6-7 months after planting (MAP), with increasing per capita incomes especially for most of the new cassava (Nweke et al., 2002). Cassava is usually cultivars (Ekanayake et al., 1997). intercropped or is the last crop in the Matured roots are clustered around the rotation before the fallow and is most base of the plant and extend about 60 likely to benefit from the residual cm on all sides. It is for these roots, fertilizers applied to the companion which contain from 15 to 40 percent or proceeding crops (FAO and IFAD, starch that the crop is cultivated. Under 2001). the most favourable conditions, yields of fresh roots can reach 90 t/ha while MANUAL AND MECHANICAL average world yields from mostly HARVESTING subsistence agricultural systems are 10 Cassava matures between 8 to 12 t/ha (USDA and NRCS, 2003). months after planting. According to Cassava is mostly harvested by research, Amponsah et al., (2014), hand or hand tools (Fig. 8), lifting the Bobobee et al., (2014), Agbetoye (2003) lower part of stem and pulling the roots and Nweke (2001), the most difficult out of the ground, then removing them operation in cassava production is from the base of the plant by hand. The cassava harvesting. Cassava is a highly upper parts of the stems with the leaves perishable crop. It starts to deteriorate as are removed before harvest. Levers and early as one to three days after harvest; ropes can be used to assist harvesting. thus harvesting cassava should be A mechanical harvester can also be done at the right time and in the proper used. Mechanical harvesters, like those way (Kuiper et al, 2007; IITA, 2004). developed in Brazil would grab onto Harvesting cassava too early results the stem and lift the roots from the in low yield and poor eating quality. ground (Kuiper et al, 2007). It is not In most cases when the roots are left advisable to harvest cassava right after 426 Mechanisation of Cassava (Root and Tuber Crops)

a heavy rain or when the soil is too wet (Ekanayake et al, 1997) because at this time, the roots have high water content, which makes them difficult to store. Also, wet soil particles would stick easily to the roots and harvesting implement especially if the soil is clayey, thus, making the roots hard to clean and implement difficult to use (International Starch Institute, 2002). Fig. 8. Manual harvesting techniques According to Philippine Root Crops and tools Information Service (2005), harvesting Mechanical Cassava harvesting cassava during relatively dry weather Manual cassava harvesting is a time- is the best since the soil does not stick consuming activity, stressful and full to the harvesting implement or roots of drudgery, especially during the dry easily. During the harvesting process, season and is a major constraint for the cuttings for the next crop are cassava commercialization in sub- selected. These are kept in a protected Saharan Africa. Until recently, there location to prevent desiccation (Kuiper are no commercial mechanical cassava et al, 2007). harvesters in use by cassava growers in Africa. This makes cassava production to be full of drudgery, unattractive to the youth and dependent on aging farmers, who produce limited output. The difficult way of harvesting cassava manually in the dry season it is a painful exercise and workers get blisters in the palms when harvesting. Mechanisation of Cassava (Root and Tuber Crops) 427

Fig. 9. At maturity, the eroded ridges serve as ‘compass’ to guide the operator to harvest efficiently. In response to the above challenge, patent No. 17219 from 2013 for 20 agricultural engineers at the Kwame years. This development is to boost the Nkrumah University of Science and mechanisation of cassava production, Technology (KNUST), Kumasi, especially harvesting in Africa. A major Ghana have invented an innovative agronomic requirement of the harvester tractor-drawn device that harvests is that the crop must be planted in rows cassava mechanically. The mechanical particularly on ridges wide apart to take cassava harvester is christened: “TEK the tractor track width so that the tyres Mechanical Cassava Harvester (TEK walk in the furrows while harvesting MCH)”, has been granted an OAPI (Fig. 9).

Fig. 10 Coppiced cassava stems ready for mechanical harvesting. 428 Mechanisation of Cassava (Root and Tuber Crops)

The implement in operation goes leaving about 30 cm above ground beneath the cassava root cluster, (Fig. 10). This is to be lower than the excavates and exposes them to the tractor under body clearance to enable surface for easy collection. It is very the tractor to pass over the cut plants suitable for harvesting all tuber crops. easily. The uncut stems serve as handle Prior to mechanical harvesting, the for lifting the uprooted root clusters cassava plants have to be coppiced from the ground (Fig. 11).

Fig. 11 Mechanical cassava harvesting.

The TEK Mechanical Cassava huge potential of cassava as food and Harvester (TEK MCH) industrial raw material. It has been The TEK MCH (Fig. 11) is one-metre- evaluated in Ghana and South Africa wide with slatted conical mouldboard for large-scale cassava production. and weighs 300 kg. It is lighter than The development of the harvester most disc ploughs. The device harvests has come about through several years cassava at a rate of 1sec/plant or less, of experimentation and modifications compared to 5-10 mins/plant to harvest to the present stage. This device is an manually, especially in the dry season appropriate mechanisation technology when the soil is hard. The harvester is solution to the problems cassava farmers one solution developed to unlock the face developing countries. The only Mechanisation of Cassava (Root and Tuber Crops) 429

spare part on the device is the digging especially during the peak of the dry blades, which have been developed season when the soil is very hard. with a special chemical composition Soils that are too moist adhere to the to enable it to be durable and wear digging blades causing a lot of non- resistant. The blade is produced either scouring effects. Very soft soils do not through steel casting or forging. The aid mechanical harvesting as the tractor TEK MCH harvester performs best wheels slip leading to reduced traction.

Fig. 12. The TEK Mechanical cassava harvester The device is fuel efficient and requires detachment. The machine is efficient; nearly the same amount of fuel like any prevents root damage and meets other three-bottom ploughs. When harvesting, demands for effective harvesting it cuts deeper than the mouldboard and operations (Figs. 13 & 14) including disc ploughs. The additional advantage leaving the harvested field ploughed for of the device is that after harvesting, subsequent crop establishment. the field is ploughed and ready for subsequent operation, thus saving fuel, time, money and tear and wear (Fig. 12). In operation, the harvester goes down to about 30cm under the root cluster, excavates the soil, raises the tubers and lays them on the soil surface for manual collection and tuber 430 Mechanisation of Cassava (Root and Tuber Crops)

Fig. 13. After mechanical cassava harvesting, the field is ploughed. The main entry point for the use of the and machinery owners to train them mechanical harvester is for farmers to adopt row/ridge planting to comply to change from their old practice of with mechanical harvesting. When this planting cassava in haphazard manner concept is imbibed by farmers, tractor to planting in rows/ridges to comply operators and machinery owners, with mechanical harvesting. There is the technology will be feasible and the need to work with farmers’ groups sustainable.

Fig.14 Mechanical yam harvesting demonstration at Wenchi MOFA Research Station in 2013. Mechanisation of Cassava (Root and Tuber Crops) 431

It is the hope of the engineers and damage to the tubers during the scientists that government will process of harvesting. In dry and encourage the widespread adoption in hard soils, mechanical harvesting Ghana by tasking the relevant agencies damage is reported to be minimal to liaise with KNUST to train farmers, when compared to manual the youth and tractor operators on the harvesting. Manual harvesting also proper use of the device, and to procure barely meets the demands of the the device for farmers throughout the market and the developing cassava country. In so doing, it is hoped within a industry couple of years, this technology would be popular and it will encourage the • Reduce drudgery. Agricultural youth to take to farming as a business. labour is aging and requires Agricultural labour is aging on the innovation and mechanization continent. The nationwide adoption to reduce drudgery. Drudgery in and use of the technology will promote cassava harvesting was evaluated the increased production of cassava by measuring the heartbeat of the and other tuber crops for export and labourer (manual workers and industry. Government would also reap tractor operators) before, during the benefits of its investment in tertiary and after harvesting. The ease of educational institutions. The device mechanical harvesting is explained could also be produced and exported by the low heart rate profile of the to generate foreign exchange for the tractor operator as compared to the country and motivate other scientists to working heart rates of the manual tackle national challenges with pride. harvesters.

Advantages of TUBER DAMAGE IN mechanical harvesting MANUAL VERSUS MECHANICAL HARVEST • Saves time and fuel. The TEK Root tuber damage assessment Mechanical Harvester can uproot Cassava deteriorates after 24 h after one plant per second and cover a harvesting due to its high moisture hectare within two hours. content. Any bruises and damage will accelerate tuber deterioration and • Quality of tubers. The mechanized spoilage (Kawano, 2011). Cassava root and manual harvesting methods damage caused during harvesting was differ with regard to degree of 432 Mechanisation of Cassava (Root and Tuber Crops)

due to either shallow harvesting depths tubers after harvesting should be sorted or relatively deeper root penetration or and weighed separately to determine the longer horizontal root spread beyond the tuber damage as a ratio of the damaged harvester operating width. Quantitative weight over the total weight of both methods were employed to determine damage and whole tubers (Fig.14). root damage. Damaged and whole

Fig. 15 Tuber damage after manual harvesting The percentage damage for each but have cuts and bruises that could harvesting method (manual or render it unsuitable for long storage. mechanical) was computed by dividing the damaged cassava weight by the total yield (Fig. 16). Farmers, market women and processors use the qualitative (eye-balling) approach to assess damage. From farmers and processors perspectives, cassava root damage was assessed when the tubers do not come out whole after harvesting Mechanisation of Cassava (Root and Tuber Crops) 433

Fig. 16 Tuber damage of Afisiafi cassava variety based on harvesting method

OPERATIONAL PARAMETERS operate to prepare seedbed and excavate (FUEL CONSUMPTION, the cassava root cluster were measured IMPLEMENT DRAUGHT using a 10 tonne commercial electronic FORCES AND WHEEL SLIP) dynamometer (RON 2125S®, Israel) DURING MECHANICAL with a digital data logger (Fig. 17). HARVESTING Draught, speed and slip In operation, the dynamometer is measurements attached between a pulling tractor and In Ghana the draughts developed by the the instrumented tractor that hitches the ploughs, harrows and harvester as they implement.

Fig. 17. Implement draft determination by RON 2125S electronic dynamometer Draught forces are measured in the harvesting (load). Load conditions transport position (no load) and when and draught force measurements engaged in the soil during work and were taken after the implement has 434 Mechanisation of Cassava (Root and Tuber Crops)

stabilized in the soil at the operating Figure 8 shows the implement draught depth. Average speed of operation measurement procedure with one tractor was derived from the time taken for pulling the instrumented one hitching a the tractor implement assembly to ridger. The RON 2125S dynamometer traverse a fixed distance marked on logs the force measurements, which the field. To measure implement slip, were later transferred to a computer the distance covered by 10 rear tyre and analysed with popular spreadsheet revolutions when travelling in no-load programmes (Fig. 18). positions and when working were used.

Fig. 18. Draught force profiles for mechanical cassava harvester in travelling (no load) and in working situations (load)

Fuel consumption, wheel mean fuel consumption of 22.26 l/ sip and travel speed ha at Akatsi compared with 20.44 l/ Table 2 depicts the mean fuel ha at Anwomaso. During the tests, it consumption, wheelslip and travel was observed harvesting on the flat speeds for mechanical cassava has higher fuel consumption than harvesting at Akatsi and Anwomaso. harvesting on the ridges. The harvester recorded the highest Mechanisation of Cassava (Root and Tuber Crops) 435

Table 2. Mean tractor fuel consumption, travel speed and wheel-slip (%) for mechanical cassava harvester at Akatsi and Anwomaso in Ghana

Parameter Akatsi Anwomaso

Fuel consumption 22.26 20.44

Wheel slip (%) 12.92-14.93 8.19-14.80

Travel speed (km/h) 4.98 5.49

The highest mean working speed of for mechanical harvest. The higher fuel 5.49 km/h was obtained at Anwomaso, whilst the lowest speed of 4. 98 occurred consumption values at Akatsi could be at Akatsi. However, no statistical due to the relatively dryer soil coupled difference (p<0.05) existed between with a higher soil bulk density and the two sites. The above speeds are higher penetration resistance. higher than the 2.4 – 4.1 km/h Bobobee In Table 3, the performance of et al, (1994) reported for the Leipzig the mouldboard plough, disc harrow mechanical harvester but lower than and the harvester using the three-point the values Ospino et al, (2007) reported hitch dynamometer and data logger in for the CLAYUCA Cassava harvester South Africa are shown. The speed, prototype, which had an operational specific fuel consumption, engine speed of 7.0 km/h. Several factors such power, wheel slip and work rate results as wheel slip, moisture content, depth agree with those obtained in Ghana of penetration, operator experience for the harvester. The specific fuel and skill etc. could have caused these consumption for the disc harrow is differences in mean fuel consumption nearly 50% lower than the mouldboard plough and harvester. 436 Mechanisation of Cassava (Root and Tuber Crops)

Table 3. Plough, disc harrow and mechanical cassava harvester performance in South Africa

Parameter Mouldboard plough Disc harrow Harvester

Speed (km/h) 5.35 9.05 5.01 Fuel rate (l/h) 21.94 20.85 18.49 Specific fuel 22.92 13 20.56 consumption (l/ha) Work rate (ha/day) 9.56 16.29 9.01 Engine power (kW) 57.96 53.39 43.42 Drawbar power (kW) 26.02 20.32 26.75 Wheelslip (%) 9.1 11.62 16.12 Implement efficiency 31.59 - 91.72 (kN/m2) Area (m2) 0.58 - 0.22 Working depth (mm) 250 140 200 Width of cut (m) 1.8 3.3 1 MC (%) 15 15 15 Clay (%) 12 12 12

HEART RATE AND rate data are collected simultaneously DRUDGERY ESTIMATION IN at a sampling rate of 5 s interval using CASSAVA HARVESTING the POLAR® RS800CX Accurex There are several ways of determining instrumentation (Polar Electro, Oy, drudgery of stress of workers when Finland) as shown in Fig. 19. Data undertaking physical activities that are from the receiver is downloaded painful and stressful. In this study, heart to a computer for visualisation and rate is used as proxy for the intensity processing by popular spreadsheets. of physical activity or manual work in agriculture. To estimate the energy expenditure and stress and drudgery induced in cassava production heart Mechanisation of Cassava (Root and Tuber Crops) 437

Fig. 19 The polar (RS800CX) heart rate monitor and chest strap sensor used to estimate drudgery. Drudgery was estimated for manual harvesting drudgery has been reported. planting, weeding and harvesting Corresponding energy consumption and mechanical land preparation and values were used to calculate the harvesting activities of operators mandatory rest periods required for by evaluating the heart beats of the each operation. workers during work. In this paper only

Fig. 20. Manual cassava harvester’s heart rate (HR) for drudgery evaluation 438 Mechanisation of Cassava (Root and Tuber Crops)

In Fig. 20, heart beats of manual workers heart rates are indicative of high energy and tractor operators were measured expenditure, which requires longer at rest before work, during work and periods to rest to recuperate and regain after work (recovery). Higher working lost energy.

Fig. 21. Drudgery evaluation in manual and cassava harvesting methods using heart rates of tractor operator and manual harvester. Figure 21 compares the heart rates of CONCLUSIONS manual harvesters with that of tractor Cassava has a number of attributes a tractor operator when harrowing the that make it attractive as a crop to cassava field during seedbed preparation promote under the climate change and when harvesting the same cassava adaptation strategy for sub-Saharan field at crop maturity. The heart rate Africa. The crop also provides an profiles show clearly the higher heart excellent insurance against famine for beats of the manual workers when farming communities. It is expected compared with those of the tractor that the development of appropriate operator. The lower heart rate profiles prototypes for cassava production of the same tractor operator confirm and processing coupled with capacity that mechanical cassava harvesting is building on cassava and tuber crops not as stressful as manual harvesting, production, processing and enterprise and it call for support and promotion of development will result in higher mechanical harvesting. revenues and better working conditions Mechanisation of Cassava (Root and Tuber Crops) 439

for the labour force, which is largely mechanical cassava and tuber crops composed of women (over 80 percent). harvesting technology that is at the level Tests to date show that several factors of users’ needs and resources should are critical for successful mechanised be generated and promoted. Over the harvesting of fully matured cassava medium and long term, the harvester crop. These include tractor speed, soil project will need the constant support physic-chemical properties, depth of of a local research and development penetration of digging share, stem size system. and inclination, depth and spread of There is the need to try the root cluster as it affects damage to roots. harvester all year round during periods when it is hoped the moisture content will RECOMMENDATIONS be higher, and compare soil penetration Mechanised tuber crop harvesting, resistance, draft, speed, tuber damage far from being perceived as grandiose results with those obtained during the technology push academic exercise, dry season. Since majority of farmers the results are new ideas that would in this country plant cassava on the flat lead to modern practices in cassava and in a haphazard manner, it will be and tuber crops production. Instead of necessary to train farmers and tractor waiting for end-users to reach the level operators to plant on ridges. of the requirements of a technology, 440 Mechanisation of Cassava (Root and Tuber Crops)

REFERENCES

Agbetoye, L.A.S. (2003). Engineering challenges in developing indigenous machinery for cassava production and processing. In: Proceedings of the Annual Conference of the Nigerian Society of Engineers, Ibadan, Nigeria, 8–12 December pp. 80-86. Amponsah, S.K., Bobobee, EYH., Okyere, J.B., Aveyire, J., King, S.R. and Sarkodie- Addo, J. (2014). Mechanical cassava harvesting as influenced by seedbed preparation and cassava variety. Transactions of the ASABE 30(3):391-403 · Ayoola OT, Makinde EA.(2007). Complementary organic and inorganic fertilizer application: influence on growth and yield of cassava/maize/melon intercrop with a relayed cowpea. Aust. J. Basic & Appld. Sci. 1(3):187-192. Bobobee, E.Y.H., Okyere, J.B., Agyare, W.A., Amponsah, S.K., King, S.R., Aveyire,J and Sarkodie-Addo,J.(2013). Performance evaluation of prototype mechanical cassava harvester in three agro-ecological zones in Ghana. Ghana Journal of Agricultural Science, 48:3-19. Ekanayake, I. J., Osiru, D. S. O., & Porto, M. C. M. (1997).Agronomy of cassava. IITA Research Guide 60. El-Sharkawy, M.A and L.F. Cadavid. (2000). Genetic variation within cassava germplasm in response to potassium. Experimental Agriculture 36:323-334. Ennin, S. A., Otoo, E., & Tetteh, F. M. (2009). Ridging, a mechanized alternative to mounding for yam and cassava production. West African J. Appl. Ecol., 15: 1-8. FAOSTAT (2013). Cassava a 21st century crop. FAOSTAT Statistical data base (http:// faostat.fao.org). (Accessed: 20-12-2016). FAO and IFAD. (2001). The Global Cassava Development Strategy and Implementation Plan. Proceedings of the Validation Forum on the Global Cassava Development Strategy, Rome, 26-28 April 2000. 1:14-59. GTZ and Stumpf, E. (1998). Post-harvest loss due to pests in dried cassava chips and comparative methods for its assessment – A case study on small-scale farm households in Ghana. Humboldt University, Berlin, Germany. Available online: http://www.fao.org/wairdocs/x5426E/x5426e02.htm#1. (Accessed: 14-12-2016). Gutteridge, R.C. and Shelton, H. M. (1994). The role of forage tree legumes in cropping and grazing systems. In: Gutteridge R.C. and Shelton HM (eds.) Forage Tree Legumes in Tropical Agriculture. CAB International, United Kingdom. Herren, H.R., P. Neuenschwander, R.D. Henessey, and W.N.O. Hammond. (1987). Introduction and dispersal of Epidinocarsis lopezi (Hym., Encyrtidae), an Mechanisation of Cassava (Root and Tuber Crops) 441

exotic parasitoid of the cassava mealybug Phenacoccus manihoti (Hom., Pseudococcidae), in Africa. Agriculture, Ecosystems and Environment 19:131– 144. Howeler, R.H. (2008). Long-term effect of cassava cultivation on soil productivity. Field Crops Research, IFAD and FAO (2005). A Review of Cassava in Africa with Country Case Studies on Nigeria, Ghana, the United Republic of Tanzania, Uganda and Benin. Proceedings of the validation forum on the global cassava development strategy, Volume 2, Rome. IITA. (2004). Nigerian’s Cassava Industry: Statistical Handbook. International Starch Institute. (2002). Cassava Plantation, Science Park Aarhus, Denmark. Available online:http://www.starch.dk/isi/papers/TM29%20 Cassava%20Plantation%20EB.pdf. (Accessed: 13-12-2016). Kawano, K. (2011).The triumphant Cassava Chronicled by foresight, political will and accountability. Journal of Root Crops, 37(2):101-110. Kuiper, L., Ekmekci, B., Hamelinck, C., Hettinga, W., Meyer, S. and Koop, K. (2007). Bio-ethanol from Cassava. Ecofys Netherlands BV, pp 1 – 38. Netherlands. 104 Available online: http://www.probos.net/biomassaupstream/pdf/ FinalmeetingEcofys.pdf. (Accessed: 14-12-2016). Melifonwu, A., James, B., Aihou, K., Weise, S., Awah, E., Gbaguidi, B. (2000). Weed Control in Cassava Farms: IPM Field Guide for Extension Agents. IITA. Molina, J.L and El-Sharkawy, M.A (1995). Increasing crop productivity in cassava by fertilizing production of planting material, Field Crop Research, 44:151-157. Muma A.K. (2000). Animal Power for Weed Control in Kaoma District, Zambia. In: Animal Power for Weed Control. A resource book of the Animal Traction Network for Eastern and Southern Africa, edited by P. Starkey and T. Simalenga. Technical Center for Agricultural and Rural Cooperation (CTA), The Netherlands. Nweke, F. I. (2004). New challenges in the cassava transformation in Nigeria and Ghana. EPTD Discussion Paper No. 118 (pp. 10-67). Washington, D.C.: Intl. Food Policy Research Institute. Nweke, F.I., Dunstan, S.C.S and Lynam, J.K. (2002). The cassava transformation: Africa’s best kept secret. Lansing, Mich, USA: Michigan State University Press. O’Hair, S. K. (1995). New Crop Factsheet: Cassava. Tropical Research and Education Center, University of Florida. Available online: http://www.hort.purdue.edu/ newcrop/cropfactsheets/cassava.html. (Accessed: 14-12-2016). Philippine Root Crops Information Service. (2005). Cassava, VISCA, Baybay, Leyte. Available online: http://www.da.gov.ph/tips/Cassava.pdf. (Accessed: 13 – 12- 442 Mechanisation of Cassava (Root and Tuber Crops)

2016). USDA and NRCS (2003). Plant Guide – Cassava: Manihot esculenta Crantz. National Plant Data Centre, Baton Rouge, Louisiana and Pacific Islands, Mongmong, Guam. Available online: http://plants.usda.gov/plantguide/pdf/cs_maes.pdf. (Accessed: 14-12-2016). 443

Eco-design options for processing gari in Ghana

Birkved, M.1, Aidoo, R2. and Wangel, A3. 1Morten Birkved DTU Management Engineering, Technical University of Denmark [email protected] 2Robert Aidoo Department of Agricultural Economics, Agribusiness and Extension, Kwame Nkrumah University of Science & Technology, Kumasi [email protected] 3Arne Wangel National Food Institute, Technical University of Denmark [email protected]

Abstract is suggested. Initially the selection of Gari is higher value added food product gari processing sites, the observation obtained from processing raw cassava of value chain steps at the sites, and roots. Thus, it represents a potential for the construction of interview guides increased income for smallholders and are presented. The selected sites are more jobs for workers in processing. profiled and the question about how The paper focuses on the processing well they represent the total population of cassava roots into gari. This of gari processing facilities in Ghana segment of the cassava value chain is is discussed. Observations, interviews detailed in terms of socio-economic and production figures are presented and environmental impacts for three for detailed characterization of each scenarios currently practiced in Ghana processing step at the three sites. A Life at different levels of mechanization. In Cycle Assessment (LCA) for the factory the third scenario at a medium sized scenario is conducted, including the factory, challenges and achievements farming of raw cassava. It is expected in efforts to upgrade parts of the gari that relying on a conventional LCA processing business are discussed, and approach, the major impacting activities an eco-design for further upgrading will be clearing of arable land for 444 Eco-design options for processing gari in Ghana

cassava production and felling of trees remains an important contributor to to produce firewood for gari processing. food security in many African countries. Where possible, introduction of work At the same time, gari processing holds environmental impact indicators potential for increasing the income of revealed that the human health issues smallholders and has provided effective from gari processing are most likely market for value-added products as related to the roasting of the flour over well as employment opportunities for open fire to produce gari. It is suggested women in the cassava value chain. that a study is conducted to evaluate the This chapter looks at the individual use/recycling of cassava peels for the steps in the processing segment of production of biogas to fuel the roasting the cassava value chain to understand process in gari processing based on socio-economic and environmental simple, readily available and affordable impacts as currently practiced in Ghana technology in Ghana. This recycling at different levels of mechanization. will have several benefits by avoiding Three different gari processing

CH4 (a much stronger greenhouse facilities are covered: 1) a group of

gas than CO2) while considerably independent business women operating lowering smoke production and on a roadside plot at Anloga in the city worker inhalation during roasting. of Kumasi; 2) a larger cooperative Limited and/or unstable connection to operating in open air as well near a main the energy grid in rural areas makes road in a rural area north of Kumasi; local production of energy in the form and 3) a privately owned medium of biogas from peels, which otherwise sized factory two hours’ drive north of are almost not used, relevant and could Kumasi. potentially yield thermal energy with a The factory has tried out lower adverse climate change impact and completed several measures than if obtained via the grid. for upgrading the processes. The Key words: Eco-design, Gari, LCA, challenges encountered and the environmental impact experience gained are discussed. A life cycle assessment has been conducted to Introduction estimate environmental impacts and to High quality gari is the key ingredient identify eco-design options for further in the production of higher value upgrading. added food products from cassava. The farming of cassava by smallholders Eco-design options for processing gari in Ghana 445

Methods toxicity, and freshwater eco-toxicity The three gari processing sites were (see Figure 2). visited earlier by members of the Findings research team and were selected to At all three sites, the sequence of represent main forms of gari processing processes in the gari processing were in the region. However, the common the same. All workers directly involved practice of gari processing at household in the processing itself were female. level is not covered. This was a case The two immediate visual observations study and an attempt was made to cover at all three sites concerned the smoke all three forms of commercial gari emission from the roasting and the processing businesses in Ghana. piling up of peels from the initial The data collection on site was peeling of the raw cassava roots, which conducted by observations (documented is either simply discarded in huge heaps by photos); personal interviews close to the processing sites, or given with selected managers and workers or sold at a low price as animal feed, (documented by audio recording); or in the case of the factory as pesticide and in some cases by records kept on (the peels contain cyanide which can be site. Data were compiled on volumes/ used as a pesticide). mass of materials, energy, chemicals At the roadside facility in urban and other inputs for each step in the Kumasi, not only the women doing the production and processing process. The roasting were inhaling particles from interview guides covered quantitative the smoke, also their small children information about cost of inputs and were affected. As these women were pricing of outputs, working hours and roasting the cassava with one hand, pay, and qualitative statements on while sieving with the other, the work working environment, occupational also appeared physically challenging/ hazards, and personal health, among unhealthy in terms of its intensity. others. When visiting the cooperative For the factory site, a product processing facility, several women system representing gari processing doing the roasting were interviewed was established and modelled based on their health status. They all suffered on the data collected (see Figure 1). coughing symptoms and told us about Environmental impacts potentials were feeling sick and trying to overcome the calculated according to the methods sickness by resting. One woman who indicated for climate change, human 446 Eco-design options for processing gari in Ghana

had been roasting for six years told the bricked channel and escape through about incidences of feeling weak and a closed chimney to the outside at dizzy and not being able to see properly. the top of the roof. By that, direct When she started complaining, she was inhalation of the smoke by the women sent to the hospital; here they just gave workers would to a great extent be her medication. The symptoms started avoided. However, initially the system one year ago, and now the woman is malfunctioned. The chimneys were only capable of doing the sieving, broken down and rebuilt and the stoves indicating a deterioration in her general were repaired at a substantial cost, only health and work capability. to realize that the real problem was the At the factory site, the owner thinness of the new frying/roasting pan has made efforts to follow the general types applied for this processing setup. The pans changed shape upon heating recommendation to mitigate the as they could not withstand the heat. hazardous working conditions observed The old, heavier and thicker pans were in the roasting processing step; and then re-introduced. that processors should be guided on Another upgrading initiative at how their processing centres should be the factory was the installation of a built to minimize the risk associated sun drying house to supplement the with the inhalation of the smoke during drying of cassava chips in open air. The processing. Setting up a more modern initiative would increase capacity and processing line in a different building reduce human labour in relation to the in the factory compound, the owner processing. However, after having tried installed the roaster in such a way several types of transparent materials that firewood incineration for heat to enclose the drying house, still the generation for the frying/roasting pans climate shell continues to break early were separated and the emissions of the at the top of the roofing due to the smoke mainly occurred via a chimney. exposure to direct sun and degradation This system, which is built with bricks, of the various types of the plastic films allowed the wood to be inserted and tested out as climate shell. fired up in a fireplace accessed through The LCA of the gari processing a hole in the outer wall of the building. was based on the dataset in Table 1, The smoke would be contained within which contains data collected on site. Eco-design options for processing gari in Ghana 447

Table 1: Product system inventory of cassava farming, gari processing, and transport to customer Units (all Input Value per kg Comment root)

Stick (stem part 5.00X10- from parent 1 pcs./kg Number of sticks needed to grow one kg of root plant)

Kg of fertilizer needed to grow one kg of root – pls. Fertilizer 0.00 kg/kg provide fertilizer type

Herbicides atrazine (2 pest control applications and 3.75X10- Pesticide 1 4 ltr./kg 1 manual weeding per vcrop cycle)

3.75X10- Herbicides glyphosate (2 pest control applications Pesticide 2 ltr./kg 4 and 1 manual weeding per vcrop cycle)

Litres of irrigation water needed to grow one kg of Water 0.00 ltr./kg root

4.00X10- Human labour 2 hrs./kg Human labour hrs. needed to grow one kg of root

Land 1.97 m2/kg Area of land needed to grow one kg of root

Output

5.00X10- Cassava leaves 3 kg/kg Assumption 0,5 % leave to root weight ratio

Cassava root 1.00E kg/kg

Each plant produces one stem that is cut into 10 pcs. Cassava sticks 1.00X101 pcs./kg (price ratio stick/root = 0,5 % sometimes even free)

Units (all Input Value per kg Comment root)

5.00X10- Transport work 3 tonnes*km Typically short distances around 5 km.

Units (all Input Value per kg Comment gari) 448 Eco-design options for processing gari in Ghana

The mass of harvested root needed to produce 1 kg Roots 3.15 kg/kg of gari

Water 1.19 ltr./kg Litres of water needed for production of 1 kg of gari

Diesel for 2.63X10- Litres of diesel needed to grate roots for production ltr./kg grinder 3 of 1 kg of gari

Fire wood 1.56 kg/kg Fire wood needed for production of 1 kg of gari

Sacks (for 5.00X10- Pls. provide numbers and additionally type and size pcs./kg pressing) 2 as well as recycling frequency (number of cycles)

Aluminium 9.16X10- Pls. provide numbers and additionally type and size pcs./kg basin 5 as well as recycling frequency (number of cycles)

Sacks (for pack- 6.67X10- Pls. provide numbers and additionally type and size pcs./kg aging) 3 as well as recycling frequency (number of cycles)

1.74X10- Stainless steel pans, pls. addtionally provide dura- Pans kg/kg 6 bility

Plastic liner for 6.67X10- Mass of sack liner used for 1 kg of gari, pls. provide pcs/kg packaging sacks 3 addtionally type and recycling frequency

9.52X10- Litres of diesel needed to mill peeled root for pro- Power ltr./kg 3 duction of 1 kg of gari

Diesel for 4.76X10- ltr./kg Litres of diesel needed to mill 1 kg of gari milling 4

9.90X10- Human labour 2 hrs./kg Human labour hrs. needed to produce one kg of gari

Outputs

Gari 1.00 kg/kg

5.71X10- Peels 2 kg/kg kg.

4.76X10- Volume of effluent generated per kg of gari, pls. Effluent ltr./kg 2 additionally provide starch content

Units (all Input Value per kg Comment root)

Transport work 6.30 tonnes*km Simply mass of root times distance transported Eco-design options for processing gari in Ghana 449

From the data in Table 1, the product cassava root substitutes maize. The system in Figure 1 was modelled using processing is subsequently modelled GaBi 6.3 and Ecoinvent 3.1. Basically taking into account transport from farm the cassava farming is modelled to processing center, consumption of accounting for both pesticides and land pans, fuel, plastic for packaging and consumption assuming that the firewood. Figure 1: Product system on cassava farming, gari processing and transport to customer modelled in GaBi 6.3 using Ecoinvent3.1. data for the background system.

The calculation of climate impacts per included in the global warming impact kg of gari showed that the farming and potential. When biogenic carbon is processing of cassava into gari cause included, the firewood incineration total impacts within a range which is appears as the most impacting process quite similar to that of the production in the system. However, the burning of of wheat flour. According to Figure 2, diesel fuel and hardwood is calculated transport stands out as the most serious as based on technology representative factor, when biogenic carbon is not for EU, since the largest inventory 450 Eco-design options for processing gari in Ghana

data sources have been developed substances in smoke emissions and for a European or north American hence the inventories of these processes, context. Obviously, this approach is not are representative for gari processing representative for a Ghanaian context. in Ghana. Thus lack of representative It cannot be assumed that technologies inventory for Ghana, inevitably adopted in EU countries to reduce introduces a serious weakness in the content of particles and other toxic LCA conducted.

Figure 2: Illustration of climate change impact profile resulting from production of 1 kg gari 2,5 Climate change midpoint, incl biogenic carbon (v1.06) [kg CO2-Equiv.] 2

1,5

1

0,5

0

-0,5

-1 Eco-design options for processing gari in Ghana 451

0,16 Climate change midpoint, excl biogenic carbon (v1.06) [kg CO2-Equiv.] 0,14

0,12

0,1

0,08

0,06

0,04

0,02

0

-0,02

-0,04

Analysing the contributions to impacts Furthermore, the literature documents on the human respiratory system pollution from particle emission as the (Figure 3), the same error is even more single most frequent cause of death pronounced. Transport is identified as (http://www.ipsnews.net/2016/11/ having the heaviest impact. However, air-pollution-emerges-as-a-top- from the observations and interviews killer-globally-part-1/) in emerging conducted, it appears that the burning economies, and thus complementing in the roasting segment causes serious the observations made and interviews health problems for the women workers. conducted. 452 Eco-design options for processing gari in Ghana

Figure 3: Illustration of human toxicity impact profile resulting from production of 1 kg gari based on product system presented in Figure 1 applying the ReCiPe (midpoint) impact assessment method.

0,00014 Particulate matter/Respiratory inorganics midpoint (v1.06) [kg PM2,5-Equiv.]

0,00012

0,0001

0,00008

0,00006

0,00004

0,00002

0

-0,00002

-0,00004

Figure 4: Illustration of human toxicity impact profile, cancer effects, resulting from production of 1 kg gari

Human toxicity midpoint, cancer effects (v1.06) [CTUh] 1,20E-08

1,00E-08

8,00E-09

6,00E-09

4,00E-09

2,00E-09

0,00E+00

-2,00E-09 Eco-design options for processing gari in Ghana 453

Figure 5: Illustration of human toxicity impact profile, non-cancer effects, resulting from production of 1 kg gari

4,00E-08

3,00E-08 Human toxicity midpoint, non-cancer effects (v1.06) [CTUh]

2,00E-08

1,00E-08

0,00E+00

-1,00E-08

-2,00E-08

-3,00E-08

-4,00E-08

-5,00E-08

Eco-design options and reduce the use of firewood, it would potential solutions minimize the exposure to particle The observations at all three gari pollution, and costs would decline, and processing facilities of the left over peels the residual sludge from the process can from the raw cassava roots instigated a be used as fertilizer. review of options for recycling these Earlier, the factory had received a peels. Currently, they are discarded as quotation for a biogas system at 100,000 waste, used or sold as animal feed, or Cedis (app.=USD 23,310); however – as in the case of the factory – sold the offer was rejected as too expensive. in dried form to Chinese expatriates An alternative, as illustrated below by in Ghana as a weed killer feedstock, the simple system developed in India, thus generating none or just a marginal could be manufactured in Ghana, e.g. earning. A viable alternative could be to by producers of water tanks, at a cost use the peels to produce bio-ethanol to estimated at USD 1,000-2,000. fuel the roasting of cassava. This would 454 Eco-design options for processing gari in Ghana

Figure 6: Simple Biogas system used in India.

Re-engineering the roasting process large volumes are needed for business will be captured in life cycle assessment customers in the food industry. Cassava as an improvement of climate impact. being a highly perishable crop, manual However, the reduced exposure to processing requires an extensive occupational health hazards will not be workforce to produce large volumes properly reflected, as the calculation of within a reasonably short period of impact from fire wood burning is time. flawed in the first place due to lack of data The workers at the factory are from developing countries. A common farmers, who are paid on a daily basis. measure in upgrading agricultural Attending to their own farm first, value chains is mechanization. For the they come and go according to their factory, labour and marketing are key own time. Mechanical dryers and problems. To market high quality gari, roasters would be able to replace a Eco-design options for processing gari in Ghana 455

large number of workers and produce very upsetting’. high volumes faster. Two barriers have Conclusion prohibited mechanization so far: the In the face of the adverse environmental high investment cost and the unreliable and health impacts associated with the power grid, to which the factory finally current gari processing methods in has been connected after several years Ghana, a re-design of the production of lobbying with the authorities. model to take account of the health Credit terms are prohibitive for any status of the women who are currently productive investment. One must have exposed to heat and smoke as well as a very good collateral security; the bank the likely deforestation as a result of will take several months (sometimes six continuous harvesting of trees to serve months) to process your business loan as fuel wood in the process has become application, and it will charge 20-40 % very apparent. Stakeholders should p.a. in interest rate. “When lobbying for take steps to discuss and promote the help to SMEs, you are left on your own, use of simple biogas technology to that’s the hard part”, says the factory generate heat energy from the peels owner, and continues; ‘If you get to of cassava to ensure environmental know somebody, you can link up. If I sustainability in gari processing. The produce High Quality Flour, the bigger construction of the processing chamber industry will buy and that will be good should be modelled along the new type for Ghana. The Government should at the factory site that prevents direct assist us, e.g. acquiring one good drying exposure to heat and smoke. This will or one good processing machine. also make gari processing in the country Fund facilities are politicised. …Our socially sustainable and acceptable. government only pays lip-service. It is 456 Eco-design options for processing gari in Ghana

REFERENCES

Bayitse, R, GN Laryea, G Selormey, WO Oduro, M Aggey, B Mensah, M Gustavsson, and AB Bjerre. 2014. “Anaerobic Co-Digestion of Cassava Peels and Manure: A Technological Approach for Biogas Generation and Bio-Fertilizer Production.” Journal of Applied Science and Technology 19 (1–2). Industry, Natural & Social Sciences Sector (INSS) of the CSIR: 10–17. Kemausuor, Francis, Simon Bolwig, and Shelie Miller. 2016. “Modelling the So- cio-Economic Impacts of Modern Bioenergy in Rural Communities in Ghana.” Sustainable Energy Technologies and Assessments 14: 9–20. doi:10.1016/j. seta.2016.01.007. Nguyen, Thu Lan T., and Shabbir H. Gheewala. 2008. “Life Cycle Assessment of Fuel Ethanol from Cassava in Thailand.” The International Journal of Life Cycle As- sessment 13 (2): 147–54. doi:10.1065/lca2007.06.343. Nussbaumer, T, Claudia Czasch, Norbert Klippel, Linda Johansson, and Claes Tullin. 2008. “Particulate Emissions from Biomass Combustion in IEA Countries.” In 16th European Biomass Conference and Exhibition, 40. doi:http://www.ieabcc.nl/ publications/Nussbaumer_et_al_IEA_Report_PM10_Jan_2008.pdf. Preetha, M. Soundariya 2012. Cost-effective green fuel for the kitchen. The Hindu 5 Nov 2012. http://www.thehindu.com/news/cities/Coimbatore/costeffective-green-fuel- for-the-kitchen/article4066573.ece Zhang, Siduo, Xiaotao Tony Bi, and Roland Clift. 2015. “Life Cycle Analysis of a Biogas-Centred Integrated Dairy Farm-Greenhouse System in British Colum- bia.” Process Safety and Environmental Protection 93: 18–30. doi:10.1016/j. psep.2014.02.017.