KWAME NKRUMAH UNIVERSITY OF SCIENCE AND TECHNOLOGY
COLLEGE OF AGRICULTURE AND NATURAL RESOURCES
FACULTY OF RENEWABLE NATURAL RESOURCES
DEPARTMENT OF AGROFORESTRY
EVALUATION OF THE AGROFORESTRY POTENTIAL OF Chrysophyllum albidum IN
THE AKUAPEM NORTH DISTRICT
BY
MARGARET ADU-BOADU
BSc. (HONS)
JUNE 2009 KWAME NKRUMAH UNIVERSITY OF SCIENCE AND TECHNOLOGY
COLLEGE OF AGRICULTURE AND NATURAL RESOURCES
FACULTY OF RENEWABLE NATURAL RESOURCES
DEPARTMENT OF AGROFORESTRY
EVALUATION OF THE AGROFORESTRY POTENTIAL OF Chrysophyllum albidum IN
THE AKUAPEM NORTH DISTRICT
BY
MARGARET ADU-BOADU
BSc. (HONS)
JUNE 2009
KWAME NKRUMAH UNIVERSITY OF SCIENCE AND TECHNOLOGY
COLLEGE OF AGRICULTURE AND NATURAL RESOURCES
FACULTY OF RENEWABLE NATURAL RESOURCES
DEPARTMENT OF AGROFORESTRY
EVALUATION OF THE AGROFORESTRY POTENTIAL OF Chrysophyllum albidum IN
THE AKUAPEM NORTH DISTRICT
A THESIS SUBMITTED TO KWAME NKRUMAH UNIVERSITY OF SCIENCE AND
TECHNOLOGY IN PARTIAL FULFILMENT OF THE REQUIREMENTS FOR THE
MASTER OF SCIENCE (MSc.) DEGREE IN AGROFORESTRY
BY
MARGARET ADU-BOADU
BSc. (HONS)
JUNE 2009
DECLARATION
I hereby declare that this submission is my own work towards the Master of Science degree in Agroforestry and thus all references and quotations cited in support of the results and the concomitant arguments have been duly acknowledged.
……………………….
Margaret Adu-Boadu
Student
……………………….. ……………………
Prof S. J. Quashie-Sam Dr Olivia Agbenyega
Supervisor Head of Department
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DEDICATION
This work is dedicated to my husband, Mr Samuel Adu-Boadu and all my children.
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ABSTRACT
In the selection of trees for any agroforestry system there is the need for its evaluation, in order to get the tree species that will be suitable for a particular locality. One of such trees that can be found growing successfully in the Akuapem North District where the research was conducted is the Chrysophyllum albidum. This is one of those neglected and under- utilized wild fruit tree species of our forests. Investigations were conducted into the potentials of Chrysophyllum albidum in towns and villages such as Adawso, Asempaneye, Bewase, Kabu, Konko, Nyamebekyere, Saforo and Tinkong. Secondly, various pre- germinating treatments were applied to the seeds to establish the best treatment options. In all, there were seven treatments: T1 (seeds sown fresh), T2 ( seeds soaked in water for 8 days), T3 (seeds soaked in hot water), 100 C, T4 (seeds cracked and soaked overnight), T5 ( seeds soaked in water for 10 days), T6 (seeds soaked in water for 12 days) and T7 (seeds cracked and sown) with three replicates. A third experiment was conducted to determine the initial growth rate of the seedlings. Proximate analysis of the fruit, seeds and leaves of Chrysophyllum albidum was done to identify the nutrient status of these parts. Food product development was undertaken and sensory evaluation was carried out using questionnaires. The result obtained from the socio-economic survey revealed that in all the 8 study sites only about 49 farmers own the trees. The fruits from one tree could be sold between GH cedis 50 and 100 at the farm-gate. The results of pre-germination treatment revealed that soaking seeds in hot water at 100 0 C (T3) destroyed the embryo as none of the seeds germinated. Highest percentage germination of 87% was recorded for seeds soaked in water for 8 days (T2), followed by seeds soaked in water for 10 days (T5) and (T1 - control) with a value of 77%. The least value of 47% was recorded for seeds cracked and soaked overnight. The experiment carried out to determine the initial growth rate of the seedlings from the pre- treated seeds indicated that the height of seedlings was highest in T2 – with a mean seedling height of 33.5 cm. T6 produced the lowest mean seedling height of 27.0 cm. The result obtained from the proximate analysis of the fruit, seeds, and leaves showed that the fruit is strongly acidic with pH value being 2.9 at 22.8 degree Celsius. One gram sample each of the leaves, seeds and the fruit (fibre) analysed at the laboratory gave the following results: the leaves had 14.9% protein, 1.2% calcium, 0.5% magnesium and 0.06% phosphorus. The seeds showed a protein content of 82%, calcium 0.3%, magnesium 0.03%and phosphorus 0.03%. The fruit (fibre) had protein nil, calcium 0.6s%, magnesium 0.2% and phosphorus 0.05% The sensory evaluation test also revealed that the drink from Chrysophyllum albidum fruit had the highest overall acceptability value of 43.4 followed by Chrysophyllum albidum fruit and ginger mixed drink with a value of 41.4. The least of the overall acceptability of the drinks was recorded with the orange drink having a value of 29.1. In conclusion, Chrysophyllum albidum has great potentials in enhancing the livelihood of the people in the Akuapem North District. It can play a potential role in agroforestry systems for sustainable food production and diversification of income of the people.
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ACKNOWLEDGEMENT
I am very grateful to my supervisors, Professor S. J. Quashie-Sam, Dr Olivia Agbenyega and Dr. Barnes for their contributions and supervisory role they played in this work.
Next, I would like to express my profound gratitude to Dr Barnes and all my lecturers, the senior members in the Agroforestry Department of the Institute of Renewable Natural
Resources, under the College of Agriculture and Natural Resources, KNUST, for making me what I am today.
I am also indebted to my husband, Mr. S. Adu-Boadu, who permitted and assisted me to pursue this programme.
Furthermore, I would like to express my sincere gratitude to the following for their various contributions and assistance; Mr. Siaw Darfour of ADB Accra, Jemimah, Daniel, Amos,
Evangel, Mr.Boateng of the Institute of Plant Genetic Resource Centre,Bunso, Mr.Garbrah,
District Director of Agriculture, Ministry of Food and Agriculture, Akuapem Akropong, Mr.
Dziwornu formerly of UCC, Enock Opoku (research and teaching assistant at the
Department of Agroforestry), Sussie, and all my course mates.
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TABLE OF CONTENTS
DECLARATION … … … … … … … i
DEDICATION … … … … … … …… … ii
ABSTRACT… … … … … … …… … iii
ACKNOWLEDGEMENT … … … … … … iv
TABLE OF CONTENTS… … … … … … …… v
LIST OF TABLES… … … … … … …… … x
LIST OF FIGURES… … … … … … …… xi
LIST OF PLATES … … … … … … …… … xii
Chapter One … … … … … … …… … 1
1.1 Background of the Study … … … … … … 1
1.2 The Problem Statement … … … … … … 5
1.3 Justification of the Study … … … … … … 7
1.4 Aim and Objectives … … … … … … 8
1.6 Research Questions … … … … … … 8
1.5 Organization of the Study … … … … … 9
Chapter Two … … … … … … …… … 10
Literature Review … … … … … … … … 10
2.1 Chrysophyllum albidum in Agroforestry … … … … 10
2.2 Meaning of Agroforestry … … … … … … 11
2.2.1 Need for Agroforestry … … … … … 12
2.2.2 Characteristics of Agroforestry … … … … 12
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2.3 Agroforestry Potentials of Tree and Shrub Species … … 13
2.3.1 Nitrogen Fixation … … … … … … 14
2.3.2 Soil Improvement … … … … … … 15
2.3.3 Soil Conservation … … … … … … 16
2.3.4 Windbreaks and Shelterbelts … … … … 17
2.3.5 Supply of Fuelwood, Timber, Food and other Products … 18
2.2.6 Potential Negative Effects of Trees on Soils … … 20
2.4 Chrysophyllum albidum … … … … … … 21
2.4.1 Taxonomy of Chrysophyllum albidum G. Don … … 21
2.4.2 The Tree of Chrysophyllum albidum … … … 23
2.4.3 Nutritive Value of Chrysophyllum albidum Fruit … … 25
2.4.4 Ecology and Distribution of Chrysophyllum albidum … 26
2.4.5 Relationship with Environment … … … … 27
2.4.6 Chrysophyllum albidum Cultivation … … … 29
2.4.7 Dormancy of Seeds … … … … … … 30
2.4.7.1 Types of Seed Dormancy … … … … … 31
2.4.7.2 Causes and Methods of Breaking of Dormancy … … 31
2.4.8 Pests and Diseases of Chrysophyllum albidum … … 34
2.4.9 Post–Harvest Pests and Diseases of Chrysophyllum … 35
2.4.10 Post-Harvest Handling and Treatment … … 36
2.4.11 Uses of Chrysophyllum albidum … … … … 38
Chapter Three … … … … … … …… … 40
3.1 Selection Of Study Area … … … … … … 40
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3.2 Description Of The Study Area … … … … … 40
3.2.1 Relief and Drainage … … … … … … 42
3.2.2 Vegetation… … … … … … …… 42
3.2.3 Soils and Climate … … … … … … 44
3.2.4 Population, Ethnicity and Economic Activities … … 44
3.3 Study Methodology And Data Collection … … … … 46
3.3.1 Socio-Economic Survey … … … … … 46
3.3.2 Experiments To Determine Germination Percentages … 48
3.3.3 Initial Growth Rate Experiments (Growth Parameters) … 49
3.3.4 Proximate Analysis of Fruit, Leaves and Seeds … … 50
3.3.5 Food Product Development … … … … 50
3.4 Data Analysis and Analytical Tools … … … … … 51
3.5 Limitations of the Study … … … … … … 52
Chapter Four… … … … … … …… … 54
Results … … … … … … … … … 54
4.1 Characteristics of Respondents … … … … … 54
4.1.1 Age Distribution of Respondents … … … … 55
4.1.2 Educational Level of Respondents … … … … 56
4.1.3 Ethnicity … … … … … … …… 56
4.1.4 Land Ownership and Size of Farm Holdings … … 57
4.1.5 Number of C. albidum trees owned by Respondents … 58
4.1.6 Marketing Strategies of Fruits … … … … 58
4.2 Cumulative Mean Daily Germination … … … … … 60
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4.3. Initial Growth Rates of C. albidum Seedlings … … … 61
4.4 Proximate Analysis of fruit, leaves and seeds … … … 65
4.4.1 Nutritive value of various parts of Chrysophyllum albidum … 65
4.5 Food Product Development … … … … … …… 65
4.5.1 Drinks… … … … … …… … … 66
4.5.2 Pastries … … … … … … …… 72
Chapter Five … … … … … …… … … 78
Discussion … … … … … … … … … 78
5.1 Chrysophyllum albidum as a Source of Livelihood for the People … 78
5.2 Germination of Chrysophyllum albidum Seeds … … … 80
5.3 Initial Growth Rate of Chrysophyllum albidum Seedlings … … 82
5.4 Proximate Analysis of Chrysophyllum albidum Fruit,
Leaves, and Seeds … … … … … … …… 83
5.5 Food Product Development … … … … … … 84
5.6 Agroforestry Potential of C. albidum… … … … … 85
5.6.1 Nitrogen Inputs and Soil Improvement … … … 85
Chapter Six …… … … … …… … … … 88
Conclusion And Recommendations … … … … … 88
6.1 Conclusions … … … … … … …… … 88
6.1.1 The implication of the results … … … … 89
6.2 Recommendations … … … … … … …… 91
References … … … … … … … … … 93
Appendices … … … … … … … …… 102
viii
Appendix 1: Questionnaire For Socio-Economic Survey … … … 102
Appendix 2: Tables … … … … … … … 116
Appendix 3: … … … … … … …… … 120
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LIST OF TABLES
Table 3.1: Treatments for the germination test experiment… … … 49
Table 3.2: Hedonic Scale of Sensory Evaluation… … … … … 51
Table 4.1: Level of education of tree owners interviewed… … … … 56
Table 4.2: Number of C. albidum trees owned by respondents… … … 58
Table 4.3: Marketing strategies of fruits by tree owners… … … … 60
Table 4.4 Mean Percentage Germination of C. albidum Seeds … … … 61
Table 4.5: Effects of pre-germination treatments of seeds on
the initial growth rate of C. albidum seedlings … … … 61
Table 4.6: ANOVA of Height of Seedlings … … … … … 62
Table 4.7: ANOVA of Breadth of Leaves … … … … … … 63
Table4.8: ANOVA of Length of Leaves … … … … … … 63
Table 4.9: ANOVA of Number of Leaves … … … … … … 64
Table 4.10: Nutritive value of various parts of Chrysophyllum albidum … … 65
Table 2: No. of Seeds germinating on a particular day after sowing
C. albidum seeds … … … … … … …… … 116
Table 3: Anova Of Height Of Seedlings … … … … … … 117
Table 4: Anova Of Diameter Of Leaves … … … … … … 117
Table 5: Anova Of Length Of Leaves … … … … … … 118
Table 6: Anova Of Number Of Leaves … … … … …… … 118
Table 7: ANOVA of Number of Root Hairs … … … … … 119
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LIST OF FIGURES
Figure 3.1: A Map showing the study area … … … … … 31
Figure 4.1: Towns surveyed and the number of tree owners interviewed … … 54
Figure 4.2: Age distribution of tree owners … … … … … 55
Figure 4.3: Appearance/colour of products (Drinks) … … … … 67
Figure 4.4: Aroma of Products (Drinks) … … … … … … 68
Figure 4.5: Texture of products (Drinks) … … … … … … 68
Figure 4.6: Mouth feel of products (Drinks) … … … … … 69
Figure 4.7: Sweetness of products (Drinks) … … … … … 70
Figure 4.8: Aftertaste of products (Drinks) … … … … … 71
Figure 4.9: Overall acceptability of products (Drinks) … … … … 71
Figure 4.10: Appearance of products (Food) … … … … … 72
Figure 4.11: Aroma of products (Food) … … … … … … 73
Figure 4.12: Texture of products (Food) … … … … … … 74
Figure 4.13: Mouth feel of products (Food) … … … … … 74
Figure 4.14: Sweetness of products (Food) … … … … … 75
Figure 4.15: Aftertaste of products (Food) … … … … … 76
Figure 4.16: Overall acceptability of products (Food) … … … … 77
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LIST OF PLATES
Plate 4.1: Some of the pastries prepared with C. albidum fruits … … … 66
Plate 1: The seeds of C. albidum… … … … … … …… 120
Plate 2: The fruits of C. albidum… … … … … … …… 120
Plate 3: Seedlings of C. albidum during the pre-germination
treatment experiment… … … … … … …… 121
Plate 4: A typical C. albidum tree… … … … … … …… 121
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CHAPTER ONE
INTRODUCTION
1.1 Background of the Study
Ghana is an agricultural country. About 60% of the population are engaged in agriculture
(Tweneboah, 2000). Agriculture serves as a source of employment, food, income, foreign
exchange and raw materials for most of the nation’s industries; among other benefits.
Notwithstanding, the manner in which the farming systems are carried out in the country
has had some detrimental effects on the land, specifically on the soil. This has therefore
led to poor soil fertility and a reduction in crop yields. The desire of farmers to increase
production or output and incomes has led to the indiscriminate use of agro-chemicals like
fertilizers, and pesticides. These rather tend to worsen the situation. The use of these
chemicals can cause health hazard to lives and also our environment (Tweneboah, 2000).
Before the introduction of modern agriculture (where agro-chemicals, improved planting
materials and mechanization are used), farmers in Ghana were practising the traditional system known as the shifting cultivation. Shifting cultivation is a rotational system in which after a period of cropping, soil fertility is restored by a fallow of natural vegetation
(forest or savannah). It is fully sustainable with adequate lengths of fallow and under low population densities, but these circumstances are rarely found today (Young, 1997).
Rising human population is a threat to the continued use of traditional shifting cultivation
practices. These are gradually failing to meet the people’s food and energy needs. Efforts
to increase agricultural production to overcome food shortages have brought about
1
environmental degradation: deforestation, soil erosion and soil fertility losses (Oppong,
2002). Furthermore, rising populations mean the situation would worsen unless measures
are taken to improve the use of available land. Farmers must be able to produce food,
fodder, fuel wood and building materials on the farm without opening new land for
cultivation (Agbleze et al., 2002). Approximately 112,000 hectares of tree cover are lost every year through improper farming practices and over exploitation of wood resources
(Agbleze et al., 2002). As a result, there is the need for a sustainable land-use system.
In recent years agroforestry has been proposed as an alternative to unsustainable farming systems. A sustainable land-use system is that which meets the needs for production of present land users, while conserving for future generations the basic resources on which production depends (Young, 1997). Agroforestry is an approach to sustainable land use that does not require huge investment (Agbleze et al., 2002). “Agroforestry is a collective name for land-use systems in which woody perennials (trees, shrubs) are grown in association with herbaceous plants (crops, pastures) or livestock, in a spatial arrangement, a rotation or both; there are usually both ecological and economic interactions between the trees and other components of the system” (Lundgren, 1982). For the purposes of this study one of the early definitions is relevant, this is stated as “Agroforestry is a sustainable land-use and management system that increases total production, combines agricultural crops, tree crops and forest plants and/or animals simultaneously or sequentially, and applies management practices compatible with the cultural patterns of the local population” (Bene et al., 1977).
2
Underlining all aspects of the role of agroforestry in maintenance of soil fertility is the fundamental proposition that trees improve soils. The following facts provide enough evidence that trees apart from the direct products obtained from them improve soils.
The soil that develops under natural forest and woodland is fertile (Rhoades, 1997;
Young, 1989a). It is well structured, has a good water-holding capacity and has a store of nutrients in the organic matter. Farmers know they will get a good crop by planting on cleared natural forest.
The cycles of carbon and nutrients under natural forest ecosystems are relatively closed, with much recycling and low inputs and outputs.
The practice of shifting cultivation demonstrated the power of trees to restore fertility lost during cropping.
Experience of reclamation forestry has demonstrated the power of trees to build up fertility on degraded soil; (Young, 1997).
Most indigenous tree species are being under-utilized in agroforestry as there is over- emphasis on the use of exotic species just because there were thought to be easier to manage than indigenous species and their products more saleable (Wood and
Burley,1991). However, indigenous species, including Chrysophyllum albidum, are well adapted to the environment where they are found to grow. Once farmers know and use them, farmers can easily adopt them into their agroforestry systems. Some of these indigenous species being fruit trees can play major roles in both socio-economic and environmental development in Ghana.
3
The major socio-economic benefits of using fruit trees as components of agroforestry
systems can be summarized as: production of various products and by-products, regular
contribution to the cash economy of the farmer, possibility of staggered production of
minor foodstuffs during lean periods of staple food availability, generation of
employment potential for the farmer, risk minimization and economic complimentarity in
the sharing of scarce resources of production (Nair, 1985).
The environmental merits of fruit trees in agroforestry systems also stem from their
micro-site enrichment and macro-site amelioration capabilities. There are strong
indications of better organic matter relations (and all consequential benefits) and
improved nutrient cycling (and therefore a better nutrient economy) in the soil-plant system of fruit tree- based agroforestry practices. Moreover, appropriate planting and management schedules can be devised for using fruit trees for soil conservation and as windbreaks and shelterbelts (Nair, 1985).
Chrysophyllum albidum (White Star Apple) is an indigenous fruit tree species growing successfully in the Eastern Region, especially, Akuapem North District, parts of the
Brong-Ahafo and the Central Regions of Ghana. This tree is a cash crop and can be compared favourably with cocoa. Yet, it has received very little research attention, neither is it grown on a large scale by farmers. It is mostly found in backyard farms with other agricultural crops.
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1.2 The Problem Statement
In many countries, agroforestry is often considered a branch of forestry or environmental conservation. This has grave consequences when it comes to the allocation of resources to departments or divisions of already marginalized institutions. Tree tenure is also another constraint. Some countries have laws that make all trees, including planted ones government property (Beniest, 2001). Such laws effectively undermine attempts to persuade farmers to plant trees. Another impediment to the progress of agroforestry is the difficulty inherent in technology transfer. The unavailability of experienced agroforestry extension officers and the poor infrastructure in countries where agroforestry is acutely needed are a few examples that can be cited. Even though having trees or leaving trees on the farmlands is age-old practice to the farmers, farmers are not familiar with tree planting and management. They are also not willing to take risks considering the relatively long-term character of agroforestry interventions. Besides, there are many down- to- earth management constraints to be overcome before agroforestry systems can be implemented.
The raising, establishing, protecting and managing of trees require skills and sustained efforts new to many farmers. Water availability for nurseries, protection of young plants against domestic animals, extra time needed to manage more than one component, minimizing negative interactions between trees and crops, all these factors are likely to require additional resources, both labour and capital, which may be beyond the means of poor farmers. Credit and aid schemes have to be provided to ensure the possibility of wide participation in the establishment phase of agroforestry systems and
5
technologies (Beniest, 2001). In addition to the above problems, many indigenous species
have potentials to be used as agroforestry species, however, they have not been explored
enough to promote them in agroforestry.
In many tropical countries, an important point of discussion is whether multipurpose tree
species used in agroforestry should be indigenous or exotic. The most important factor in
all cases is to make the best choice for the farmer and for the site. In modern farming,
there may have been an over-emphasis on exotic tree species for agroforestry mainly because they were thought to be easier to manage than indigenous species and their products more saleable (Wood and Burley, 1991). This has, however, not always been true since there are situations where farmers have been unable to manage the exotic tree species.
Traditionally, there are many important lesser-known indigenous tree species that are neither planted nor adequately explored to discover their potentials to be included in agroforestry systems, but that, nevertheless, provide farmers with valuable products and services. One of such species is Chrysophyllum albidum (White Star Apple). However,
the genetic base of many of these species is being reduced as a result of deforestation and
there is also a lack of information on their ethno-botanical and socio-economic potentials.
This study therefore seeks to identify and evaluate potentials of Chrysophyllum albidum
as potential agroforestry tree and the gains from its tree products in the Akuapem North
District.
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1.3 Justification of the Study
The resource potentials of indigenous trees can be tapped through the process of domestication. Researchers have to identify these trees with the help of farmers, who know, appreciate and depend on these species for a number of tree products, before embarking on domestication (Leakey, 1994). Before proper domestication can occur, in agroforestry systems, there is the need for the tree species identified to be evaluated so as to discover their potentials in any specific locality. This should include, indigenous multipurpose species that are common locally, as well as those that are less well known or that have specialized uses. Many of these species can be identified during diagnosis and design exercises, ethno-botanical surveys or specialized marketing studies. Although the fact that local farmers currently utilize a particular species does not necessarily imply that it will be suitable for a specific agroforestry technology, such information at least suggests that the species should be examined since it is known to survive and to be acceptable under local conditions (Wood and Burley, 1991). This study shall indicate how Chrysophllum albidum can be integrated in the farming system to achieve an optimal benefit for the farmer. Farmers would also benefit from the scientific procedures and treatments given to the seeds to enhance their germination. These treatments and procedures would afford farmers in the study area an opportunity to increase the number of seedlings available to them for planting and hence increase the number of trees of
Chrysophyllum albidum they own. The management practices of seedlings that would be recommended in this study would be modern scientific agronomic practices that farmers can adopt for fast propagation and growth of the plant.
7
The detailed botanical description of the plant given in this study would help agronomists
and other scientists to identify the plant growing elsewhere with ease. The medicinal
properties of the plant provided in this study can be explored for herbal medicine which
has currently been introduced into the study of medicine at the Kwame Nkrumah
University of Science and Technology. The findings of this study will increase the
scientific knowledge in the field, the appropriate method for breaking the seed dormancy
to enhance germination as well as the development of food products using C. albidum.
1.4 Aims and Objectives
The general aim of the research was to carry out an evaluation of Chrysophyllum albidum
(White Star Apple) and its domestication in the development of agroforestry in the
Akuapem North District. The objectives were
1. To investigate and evaluate Chrysophyllum albidum as a source of livelihood
for the people in the Akuapem North District.
2. To investigate and recommend the appropriate pre-treatment for germinating
the seeds.
3. To analyze the nutritive value of the fruits, leaves and seeds; and investigate the
uses of Chrysophyllum albidum.
1.5 Research Questions
The objectives of the study were used to formulate research questions as a guide. The research questions formulated were:
8
1. What contributions do Chrysophyllum albidum tree make towards the
livelihood of the people in the Akuapem North District?
2. How can the seeds of Chrysophyllum albidum be treated to enhance their
germination?
3. What are the nutritive values of Chrysophyllum albidum and other uses of its
fruits?
1.6 Organization of the Study
This study is divided into six chapters. Chapter one is an introduction of the study.
Chapter two is a review of relevant literature on Chrysophyllum albidum, the role and characteristics of trees used in agroforestry. Chapter three describes the study area, the research methodology, which includes the experiments conducted, sources of data and a description of the data analysis. The results of the study are presented in chapter four.
Chapter five is a discussion of the results and its implications. Chapter six provides a summary of the study, the conclusions and recommendations.
9
CHAPTER TWO
LITERATURE REVIEW
2.1 Chrysophyllum albidum in Agroforestry
With the inception of agroforestry in Ghana as in other African countries, there has been the promotion of the use of exotic tree species as a woody perennial component in agroforestry systems. The indigenous tree species which are best known to farmers in most cases are neglected or being under utilized. Some of these indigenous tree species can be said to be valuable to farmers in terms of productivity and sustainability.
Productivity involves a multiplicity of outputs and sustainability implies the conservation or even improvement of the environmental aspect of the systems (Huxley, 1983).
It is towards the evaluation of Chrysophyllum albidum (White Star Apple/Akasaa) as a potential agroforestry species that literature in this study seeks to contribute. This tree species is an indigenous tree species which is also under utilized. It is also important to let the analysis in the study reflect the peculiar characteristics of the study area.
Background information on the study area is therefore provided as an integral part of the literature review.
10
In the second part, selected topics on agroforestry, agroforestry potentials of trees and shrubs species; Chrysophyllum albidum are reviewed under the following eight major sub-headings.
1. Agroforestry - its definition, need for agroforestry, its features, and
potentials of tree and shrub species in agroforestry.
2. Nomenclature and taxonomy of Chrysophyllum albidum.
3. Ecology, distribution and cultivation of Chrysophyllum albidum
4. Uses of Chrysophyllum albidum tree and its products,
5. Nutritive value of its fruits; and
6. Structural characteristics of Chrysophyllum albidum.
7. Post- harvest handling and treatment
8. Pests and diseases of Chrysophyllum albidum
2.2 Meaning of Agroforestry
Agroforestry refers to land-use systems in which trees are grown in association with crops, pasture or livestock. The association may be in time, such as a rotation between trees and other components, or in space, with the components grown together on the same piece of land. There are usually both ecological and economic interactions between the trees and other components of the system. It is the ecological interactions that are the most distinctive feature, taking place above ground (e.g. shading, evapotranspiration) below ground (e.g. root interaction with respect to water and nutrients) and through transfers of biomass, as when the litter or pruning are added to the soil (Young, 1997;
Lundgren, 1982). Agroforestry is an integrated land-use management system. Farmers
11
deliberately cultivate trees or shrubs on the same piece of land with crops and or
livestock.
2.2.1 Need for Agroforestry
Rising human population is a serious threat to the continued use of traditional shifting
cultivation practices. These are gradually failing to meet the people’s food and energy
needs (Oppong, 2002). Efforts to increase agricultural production to overcome food
shortages have resulted in environmental degradation: deforestation, soil erosion and soil
fertility losses. Agroforestry technologies offer possible solutions to both types of problems: they improve farm production at the same time combat environmental degradation (Wood and Burley, 1983). They are especially suited to small-scale farmers
in the tropics.
2.2.2 Characteristics of Agroforestry
Agroforestry has a range of characteristics or features which make it suitable for
sustainable land-use systems. Primarily, agroforestry involves two or more plant species,
with at least one woody perennial. Woody perennials include: trees, shrubs, palms,
bamboos, (Young, 1997). Species regarded as belonging to agriculture have included
mostly ( but not exclusively) herbaceous ones that were cultivated with much managerial
attention and harvested at frequent intervals for their most important economic produce,
either through repeated generations of the same short-duration species, or by repeated
harvesting from the same plant (Nair, 1985). Since two or more plant species and /or
livestock are involved, at least two or more products are obtained. The components of
12 agroforestry systems are trees, agricultural crops, pasture, livestock and soil. Other components namely insects and fish, occur in specialized systems (Young, 1997). As a result there is multiplicity of products from any agroforestry system (Young, 1997).
All agroforestry systems usually have a cycle of more than one year, because woody species included in any agroforestry system are mostly perennials and would take more than one year to start producing outputs. Even if the herbaceous /agricultural crops which may be annuals are harvested, the woody perennials continue to grow on the land.
Woody perennials have relatively long spans of the juvenile phase as well as total life
(Nair, 1985). Furthermore, agroforestry has biological and or economic interactions between the woody species and the other species. In any agroforestry system the trees grown in association with agricultural crops, pasture or livestock should have both ecological and economic interactions between the other components of the system. It is the ecological interactions that are the most distinctive feature, taking place above ground, below ground and through transfer of biomass, as when tree litter or punning are added to the soil (Nair, 1979).
2.3 Agroforestry potentials of tree and shrub species
Compared with other production systems, agroforestry presents a number of advantages which can also be regarded as its potentials for improving land use systems. These include nitrogen fixation, soil improvement and conservation, supply of mulch, providing wind protection and live fences (Huxley, 1983). Additionally, it can supply products such as fuelwood, timber, food and products for herbal medicines amongst others.
13
2.3.1 Nitrogen Fixation
Nitrogen–fixing trees can make substantial contributions to nitrogen inputs (Young,
1997). The major group consists of many leguminous species nodulating with Rhizobium
or Bradyrhizobium, these include many of the most widely used multipurpose trees, such
as Acacia, Erythrina, Gliricidia, Leucaena and Sesbania species. In addition to the above,
a limited number of non-leguminous genera, Alnus and Casuarina species, nodulate with
Frankia (Young, 1997). Nitrogen fixation is comparatively a well-studied branch of agroforestry, building upon research in agriculture and forestry. Reviews specific to agroforestry include Dommergues (1987), and Bowen et al., (1990). Particular attention has been given to the contribution of fixation to the nitrogen cycle in hedgerow intercropping (Sanginga and Mulongoy, 1995). A key feature of biological nitrogen fixation is that additional nitrogen is brought into the soil-plant system at no cost, in two respects: there is no fertilizer cost, and the loss into the atmosphere is negligible. It is well established that L. leucocephala can fix 100-500 kg nitrogen (N) ha-1per year or
more in pure stands, and 75-100 kg when in a hedgerow intercropping system. Sesbania
rostrata, grown in association with swamp-rice systems can also attain 500 kg N per
hectare per year. Other fast growing species, including Sesbania sesban, Gliricidia
sepium, Albizia lebbeck, Acacia mangium and the non-legume Casuarina equisetifolia,
fix amounts of the order of 50-100 kg per hectare per year (Young, 1997).
14
2.3.2 Soil Improvement
The properties which are likely to make a woody perennial suitable for soil fertility improvement or maintenance are:
• A high rate of production of leafy biomass,
• A dense network of fine roots, with a capacity for abundant mycorrhizal
association,
• The existence of deep roots,
• A high rate of nitrogen fixation,
• A high and balanced nutrient content in the foliage; litter of high quality (high in
nitrogen, low in lignin and polyphenols),
• An appreciable nutrient content in the root system,
• Either rapid litter decay, where nutrient release is desired, or a moderate rate of
litter decay, where maintenance of a soil cover is required,
• Absence of toxic substances in the litter or root residues,
• Absence of severe competitive effects with crops particularly for water,
• Low invasiveness,
• Production function, or service function other than soil improvement (Young,
1997).
Not all of these properties are compatible, for example, litter of high quality is not likely to have a moderate rate of decay. The last property, the existence of productive functions is not directly related to soils but is of the highest importance if the tree is to be effective in fertility maintenance. A species needs to be acceptable in agroforestry systems from other points of view, especially production. A tree might have all the desirable properties
15 as stated in Young, (1997), but, if it is not planted and maintained, it will not be effective in improving soil fertility (Young, 1997).
2.3.3 Soil Conservation
Conventional methods of soil conservation, based on earth structures, have frequently encountered problems. The current approach emphasizes the use of biological methods.
Conservation systems can be designed based on supplementary or direct use of trees and shrubs. In supplementary use, trees are added to conventional conservation works, serving to stabilize earth structures and make productive use of the land which they occupy. In direct use, the trees themselves are the agent of conservation (Young, 1997).
Trees and their litter or pruning exert both barrier and cover effects. The barrier effect checks runoff and increases infiltration. The cover effect checks raindrop impact and also runoff. A tree canopy, unless low, has little effects; what matters is a ground cover of litter or pruning. On the basis of soil-erosion theory, the most effective method of design is based on maintenance of a soil cover of at least 60% during the period of erosive rains.
The root systems of trees greatly increase infiltration and so reduce run off (Young,
1997). Moreover, the main agroforestry technologies with potential for control of soil erosion are: multi-storey tree gardens, perennial-crop combinations, contour hedgerows, trees-on-erosion control structures, windbreaks and shelterbelts.
The supply of mulch can also provide a means for soil conservation. In rain forests, evaporation can be as much as five times higher in clearings than under a forest canopy
(Lundgren and Lundgren, 1979). A layer of tree leaf litter or a mulch of pruning
16
substantially reduces evaporation, possibly having as much effect as the canopy. At
Dehra Dun, India, mulches of five tree and shrub species were applied at 4t per hectare to
a crop of wheat. As compared with an unmulched control, soil water levels were higher
than mulched treatments at all stages of crop growth, and progressively increased over
three years (Young, 1997). As expected, the effectiveness in conserving water was
inversely proportional to the speed of decomposition of the mulches, Shorea robusta
being the slowest to decompose and having the greatest effect on soil water (Tomar et al.,
1992). The same relationship was found at Abidjan, Cote d’Ivoire, where the residence
time of mulch was related to reductions in soil temperature and conservation of water in
the order Flemingia congesta > Gliricidia sepium > Leucaena leucocephala (Budelman,
1989b).
The woody perennial species involved in agroforestry species can be utilized in their
plantings to serve as live fences. Trees can be grown on a farm, usually combined with
other plants, as a live fence to keep animals in or out. Live fences are less costly to install
and are easier to maintain. Many tree species can be grown as live fences, including
Acacia nilotica, Senna siamea and Gliricidia sepium (Quashie-Sam et al., 1990).
2.3.4 Windbreaks and shelterbelts
Since there are interactions between trees and adjacent crops, all windbreaks fall within the definition of agroforestry; in the tropics, emphasis is now being given to multipurpose windbreaks, from which there is production in addition to the service function of shelter
(Young, 1997). Windbreak is the term used where the width of the belt of trees and shrubs is the minimum necessary to check wind velocity, and shelterbelts describe
17 broader belts of woodland. The terms are used interchangeably (Young, 1997). Examples are found worldwide, mainly but not exclusively in dry zones. The belts between vineyards in the Rhone valley of France, to protect vines from frost damage by the cold mistral winds, have existed for centuries (Young, 1997). Middle Eastern countries employ windbreaks along with other methods of sand–dune stabilization. They have been planted on projects to check desertification in Sahel zone of Africa (Vandenbeldt, 1990).
In China, shelterbelt systems in some cases are broad woodland belts, these have been planted for integrated purposes of protection from wind, soil conservation and production
(Moore and Ruselle, 1990). Farmers the world over plant trees for shade and shelter around their homesteads. Soil improvement certainly occurs beneath the windbreaks, and blowing of litter may lead to limited increases in soil organic matter in adjacent cropland.
Protection from wind damage is especially important for fruit crops and vines, windbreaks can be an important element in orchard management, (Norton, 1988).
2.3.5 Supply of Fuelwood, Timber, Food and other products
Agroforestry increases the supply of fuelwood and timber for construction and other uses
(Oppong, 2002). The woody perennial species can be used in any of the following agroforestry systems (to supply some of these products) the taungya system, trees-on- cropland, perennial-crop combinations, home gardens or farm and village forestry. In all these trees are managed to meet multiple purposes (Young, 1997).
The various components of an agroforestry system produce food. The trees and shrubs can yield fruits and leaves to be used as vegetables. Annual food crops can be grown
18
between or among the woody species. Leaves from the trees can be fed to livestock
(Oppong, 2002). King, (1979) pointed out that, for the resource-poor farmers who yield
no recognizable social or political power, agroforestry is the only appropriate approach to
land management whereby both food and wood products can be produced from the same
piece of land at the same time without causing deterioration of the ecosystem. Woody
perennials, because of their deep roots, are less affected by short-term water shortages than are the shallow-rooted herbaceous plants. This stabilizes the supply of food. That is to say, they produce yield during seasons when staple foods are less available. The resulting product diversity also improves the quality and quantity of food produced
(Oppong, 2002). Perhaps the most significant attribute of fruit trees that make them eminently suitable for rural agroforestry is the nutritive value of their products (Nair,
1985). Sommers, (1978) evaluated the nutritive value of various indigenous species in the home gardens of Philippines and found that such species contributed substantially to the diet of the people. Sustainable agroforestry practices involving such fruit trees are an excellent way of supplementing and enriching the diet of rural people in many developing countries (Nair, 1985).
In agroforestry, woody perennials can also provide other products, such as medicines, tannin and dyes (Oppong, 2002). The importance of the plants as natural sources of medicines has been emphasized by several people: Treben (1986), Sofowora (1993),
Kafuru (1994), Olapade (1995) and Ibironke et al., (1997). These plants are usually
available and are widely recognized by many people as edible fruits only but the
19
knowledge of their medicinal values is confined to a few individuals and families
(Olapade, 1995).
2.2.6 Potential Negative Effects of Trees on Soils
Potentially, trees can have adverse effects on soil properties, either directly or through
competing with herbaceous plants for soil resources. The effects upon soils are:
allelopathy, acidification, loss of organic matter and nutrients during harvesting (Young,
1997). Allelopathy is the release of substances by one plant which are toxic to another, in
the case under discussion the release by trees of substances that inhibit the germination or
root growth of associated crops. A tree widely known to display allelopathic interference
with crops is the black walnut (Juglans nigra), (Young, 1997). Acidification refers to conditions of low pH. In the cool temperate zone, trees which produce acids mor-type,
humus can lead to appreciable soil acidification. This is a well-known feature of conifer
plantations.
Trees accumulate considerable amounts of carbon and nutrients in their biomass, part of
which is necessarily removed during harvesting. This results in the removal of organic
matter and nutrients in tree harvests. The problem is greatest where there is whole-tree
harvesting, with gathering of branches and litter by the local population after timber
removal (Young, 1997). This factor needs to be borne in mind in the evaluation of
agroforestry systems. With fast growing trees, much of the carbon in the soil-plant
system first accumulates in the trees and, if these are harvested, benefits to the soil are
substantially reduced. From a soil management point of view, it is desirable to allow
20 branches and the litter to decay in situ, but this may conflict with social needs. In tree plantations; bark and other waste from sawmills should ideally be returned to the site; where there is intercropping, however, the high carbon: nitrogen ratio of decomposed woody material will results in nitrogen immobilization and reduction of crop yields in the short term (Young, 1997).
2.4 Chrysophyllum albidum
Chrysophyllum albidum belongs to the family Sapotaceae which contains a number of fruit trees like C. cainito, C. welwitschii, C. delvoyi, C. pruniforme and others; all indigenous to tropical Africa (Hutchinson and Dalziel, 1963; Steentoft 1988). The
Chrysophyllum albidum tree can offer more than only fruits and timber. It produces copious litter and could therefore be used to reduce soil erosion. The tree provides shade and shelter for many species including humans. Wastelands with deep soils can be reclaimed with Chrysophyllum albidum, whose deep roots bring nutrients to the surface like all other trees with deep roots. It can also be used in enrichment planting (ex situ conservation) (Osafo, 1970). Experience has shown that once farmers are aware of the economic value of Chrysophyllum albidum, they would plant more trees and participate in the efforts of reforestation. This objective however, is not always profit maximization, but is frequently for risk reduction as the Chrysophyllum albidum produces fruits even in dry season when other crops are damaged by the harmattan.
2.4.1 Taxonomy of Chrysophyllum albidum G. Don
The genus Chrysophyllum is a family of trees and shrubs well marked by latex, and alternate, simple, usually exstipulate leaves; stipules when present fall easily. The genus
21
Chrysophyllum is derived from Greek, meaning “golden-leaf” because of the colour of the hairs of some species. In a few others, however, the colour of the hairs is silvery- white. The genus Chrysophyllum, Linn. is represented in most parts of Africa by thirteen species, eight of which (including C. albidum) occur in Nigeria. However, while Keay et al., (1964) and Keay (1989) reported only seven species for Nigeria, Hutchinson and
Dalziel (1963) reported eight species including C. Prunifolium. All the Nigerian species of Chrysophyllum are tall or medium-sized trees except C. welwitschii which is a woody climbing shrub. On the other hand, Hawthorne (1995) reported only six species for
Ghana (Bada, 1997). The mature tree of Chrysophyllum albidum G. Don has been variously described by several authors ( Aubreville, 1963; Hutchinson and Dalziel, 1963;
Keay et al., 1964, Keay, 1989; Okafor, 1981).
Keay (1989) gave a very good account of the species of the genus that occur in Nigeria:
Chrysophyllum pentagonocarpum (A forest tree which grows up to 45 m high),
Chrysophyllum pruniforme (A forest species closely related to C. pentagonocarpum),
Chrysophyllum giganteum (A forest tree, to 30 m high), Chrysophyllum subnudum (An under storey tree in forest), Chrysophyllum perpulchrum (A forest tree, to 30 m high),
Chrysophyllum delevoyi (A species very closely related to C. albidum and may be no more than a variety of it. It was later cited in Ghana as a synonym of C. albidum (Abbiw,
1990)), Chrysophyllum albidum G. Don, Chrysophyllum albidum is a closed forest tree species often planted in villages.
22
2.4.2 The tree of Chrysophyllum albidum
The genus Chrysophyllum is an evergreen tropical tree. Chrysophyllum albidum is a tall
straight tree from 30 m to 60 m under favourable site conditions. The bole is sometimes
long and straight but often branched, deeply fluted occasionally with small buttresses
(about 30 cm high) at the base. The crown is usually dense (Katende et al., 1995; Irvine,
1961; Bada, 1997). The bark is thin, pale grey-brown or pale brownish-green, while the
pale brown slash exudes copious white gummy latex, a characteristic of the Sapotaceae
family. It has a network of zigzag fissures; twigs grooved (Irvine 1961; Katende et al.,
1995; Bada, 1997). It is a timber species. The wood is brownish-white, soft, coarse and open grain; very perishable in contact with the ground. It is easy to saw and plane, nails well, and takes a fine polish. (Katende et al.,1995; Opeke, 1982). The branches and the leaves (crown) form a dense canopy, so it can serve as a shade tree or used as a material for windbreaks or shelterbelts (Katende et al., 1995).
The name ‘albidum’ (white) refers to the white or silvery-grey undersurface of mature leaves, easily seen when looking up into the tree’s canopy. The lower surface of young leaves has soft golden-brown hairs and these hairs disappear with age (Keay, 1989). The mature leaves are dark green above when the leaves are usually 30 cm long and 8.9 cm broad, blanceolate, and tapering rather rapidly to the acuminate apex and wedge-shaped base (Bada, 1997). The venation of the upper surface is finely raised, that is, may be invisible or indistinct. The lateral nerves are 10-15 pairs. The midrib channel is not normally very sharp, sunken above, prominent below with clear side veins (Keay, 1989;
23
Hawthorne,1990; Katende et al., 1995; Bada 1997). The leaf stalk is up to 3 cm or 1
inch long.
The tree commonly flowers from April to June annually (Irvine, 1961; Keay et al., 1964).
Okafor (1981), however, noted that in parts of Anambra, Ebonyi and Enugu states (all in
Nigeria) flowering occurs at various times such as January-February; April-June and
September. This could be an attribute to be exploited in pollen collection (Bada, 1997).
The flowers are cream-yellow hermaphrodite very small in dense short-stalked clusters, usually in leaf axils or from above the scars of fallen leaves, (Opeke, 1982; Beentje,
1994; Katende et al., 1995; Bada, 1997).
The fruit normally appears from January to early March. The fruit of Chrysophyllum albidum is a large dehiscent berry containing 5-large flattened seeds or sometimes fewer by abortion (Gbile, 1997). The fruit is greenish-grey when immature, turning orange-red, yellowish-brown or yellow when mature. It is about 5-6 cm long and about 3.2-7 cm in diameter. It is almost spherical or rounded; glabrous or sometimes with speckles when mature, and pointed at the apex. It has a sweet, pleasantly acid, edible yellowish-brown pulp, in which are embedded about five or less seeds in 5 cells. A cross section of fruit shows seeds arranged as a star (Irvine, 1961; Opeke, 1982; Katende et al., 1995; Bada,
1997). Inside the fruits, shiny brown seeds to 2.5 cm long lie in sweet-acid edible pulp, each bean-like with one sharp edge. Or seeds 1-1.5x 2 cm, bean-like, shiny when ripe, compressed, with one sharp edge and a star arrangement in the fruit as in an apple. The
24
seed of the fruit comprises an embryo and endosperm in a brown shiny protective hard coat (Irvine, 1961; Opeke, 1992; Katende et al., 1995).
2.4.3 Nutritive Value of Chrysophyllum albidum Fruit.
The fruit is very rich in ascorbic acid (vitamin C). It has the highest content of ascorbic acid with 1000 --- 3330 mg of ascorbic acid per 100 g of edible fruit or about 100 times that of oranges and 10 times in guava or cashew. It is also an excellent source of vitamins
B and D as well as iron (Okafor and Fernandes, 1987; Bada,1997; Umelo, 1997).
Besides, the fruit contains 90% anacardic acid. The seeds inside the fruit contain oil in the endosperm (Bada, 1997). It has been reported that fruit pulp contains 21.8mg/100g ascorbic acid, while the skin contains 75mg/100g. Again, proximate analysis of the fruit pulp revealed protein content of (8.8%), lipid (15.1%), ash (3.4%), carbohydrate (68.7%) and crude fibre (4.0%), with only minor differences between pulp and skin. With the exception of calcium (100 v 250 mg/100g) and iron (10 v 200 mg/100g) in pulp and skin respectively, the mineral content of these components of the fruit were also very similar.
The levels of toxic substances in both the mesocarp and the pericarp were low, although the juice was highly acidic. Identified are high levels of tannins in pulp (627 mg/100g) and lower levels in peel (264 mg/100g). Fruit storage was best at 10oC, while for the
kernel the traditional method of storing in layers of red clay was best. The juice of fruits
has potential as an ingredient of soft drinks and can be fermented for wine or other
alcohol production. The seeds of this species are not particuarly rich in lipids (3.2%), but
linoleic (38.4%) and oleic (29.6%) acids are the main fatty acids present. Higher lipid
content (16.6%) and unsaturated fatty acids as the main component of the oil (74%) have 25 also been confirmed and hence desirable in the context of heart disease risk reduction.
The residual cake also has potential for animal feed (wanatca).
2.4.4 Ecology and Distribution of Chrysophyllum albidum
Chrysophyllum albidum is a dominant canopy tree of lowland mixed rain forest, sometimes riverine. It is widely distributed from West Africa to the Sudan with an eastern limit in Kakamega Forest, Kenya (Katende et al., 1995). Geographically it is native to Ghana, Sierra Leone, Sudan, Nigeria, Uganda ( Steentoft, 1988; Katende et al.,
1995). Its occurrence in Cameroon, Cote d’Ivoire and Gabon had been reported by
Aubreville (1963, 1964). It is found in the southeast forests of Republic of Benin though not in high concentrations. Hawthorne, (1990) claimed that the species does not occur naturally in Ghana though it is now planted for its fruits. Collections in the Herbarium of Forestry Institute of Nigeria confirm the following localities which are mostly high forest: Olokemeji Forest Reserve (F.R), Sakpoba (F.R) Obudu Cattle Ranch; Nawfia village, Awka district, Okware, Obubra district, Ogoja; Igbemo, Ekiti; around Ganguma villagse all in Nigeria. In Ghana the C. albidum are widely found growing in the forest and riverine areas. These include some parts of the Eastern Region- the Akuapim North and South Districts, Suhum-Kraboa Coaltar District, some parts of the Central Region-
Mankessim; Western, Brong-Ahafo and Ashanti regions.
26
2.4.5 Relationship with Environment
Chrysophyllum albidum is primarily a forest tree species. Its natural occurrence has,
however, been reported in diverse ecozones from the high rainfall (>2000 mm) area of
Urhonighe Forest Reserve, through Ilaro Forest Reserve (<1500 mm) in Nigeria to parts
of Niger Republic with less than 1000 mm annual rainfall (Bada, 1997). Macoboy, (1989)
has claimed that the species requires a hot climate, and all year-round water supplies.
Field observations, however, show that factors other than those of the climate may be
crucial to the occurrence and distribution of the species (Bada, 1997). For instance, the
species is yet to be encountered in the forest of Cross River and Akwa-Ibom States,
which enjoy very high rainfall (often >2500 mm) and abundant sunshine being nearer the
Equator than the dry lowland rainforests. The fact that the species is reported in Niger
Republic shows that edaphic and some other factors may play a significant role in its natural distribution (Bada, 1997).
Detailed information is not available on the occurrence of C. albidum with respect to elevation. The lowland rainforest in Nigeria and the bulk of West and Central Africa are at low altitudes. This may lead one to assume that C. albidum is a species of low elevation. However, the species has been reported to occur in parts of Idanre hills, the
Jos Plateau and Adamawa highlands, which are areas of moderate elevation (700-1200 m). The fact that the species occurs in parts of Uganda (generally of moderate elevation) and Sierre Leone (probably in the forests of the Loma Mountain region) would support the assumption that C. albidum is a species of low to moderate elevation. This would have great implications for genetic improvement (Bada, 1997).
27
Observations show that the species occurs or has naturalized in areas of varying soil types
and parent materials. It is found in much of the semi-deciduous lowland rainforests underlain by Ferruginous Tropical Soils of Basement Complex and also Ferrallitic
Tropical Soils of Coastal Plains Sands (Bada, 1997). Its absence in the forests of Cross
River and Akwa-Ibom states may suggest that the species is intolerant to excessive rainfall which may lead to waterlogging and consequently, poor soil aeration. Seedling development shows that a long and strong taproot is developed early. This may not function efficiently under waterlogged condition (Bada, 1997).
There is presently no information on site preferences for C. albidum. Existing stands, however, show that the species grows well in areas of gentle undulations with deep soils and good drainage. Under normal conditions, the species tend to avoid watercourses as well as areas of poor drainage. This would underscore the assumption that the tree is intolerant to waterlogging (Bada, 1997).
With regards to regeneration, quantitative information is not available on natural regeneration and stand replacement in C. albidum. The tree, however, fruits annually, usually from January to March. The age at which the species starts fruiting is not yet known though there is the general impression that it takes seven or more years before bearing fruit. A plausible reason is that all plantings have relied on the use of unimproved land-races, which often exhibit poor performance (Bada, 1997). This notwithstanding, copious regeneration is noticed under mature trees in the wild where the fruits are not harvested /collected by human beings. So far, the species is known to regenerate only through seeds. Under most planted trees, especially in homesteads / home gardens,
28
natural regeneration is often very rare because of intensive fruit harvest / collection
(Bada, 1997).
C. albidum is an evergreen tree rarely shedding all its leaves in any one season except
when the tree is dead or under serious stress (e.g. pest/disease attacks). It follows
therefore that a thick litter layer may not accumulate under the trees when the leaves are
of a texture that would enhance ready mineralization. There is a belief that the rapid
mineralization of the limited litter would improve the fertility and structure of the topsoil
under C. albidum trees with a consequent improvement in the development of the
undergrowth. There is, however, the need to assess, quantitatively, nutrient cycling under
C. albidum in determining its sustainability for incorporation into appropriate
agroforestry technologies (Bada, 1997).
2.4.6 Chrysophyllum albidum Cultivation
C. albidum has a hard protective seed coat which is lined with a wax-like layer which makes it difficult for water to get to the embryo. This tends to make the seed dormant.
Germination is epigeal with foliaceous and persistent cotyledons. Seed viability is very high (> 80% at maturity) but may decline rapidly with inadequate storage. A seed consists of an embryo and its stored food supply (endosperm) surrounded by protective seed coverings. When the seed separates from the plant on which it was produced, the seed is quiescent; that is, no external evidence of activity with the seed. The resumption of active growth by the embryo, resulting in the rupture of seed covering and the
29
emergence of a new seedling plant capable of independent existence is known as
germination (Hartmann et al., 1990).
For germination to be initiated, three conditions must be fulfilled. Firstly, the seed must
be viable; that is, the embryo must be alive and capable of germinating. Secondly, the
seed must be subjected to the appropriate environmental condition: available water
(moisture), proper temperature regimes, a supply of oxygen and sometimes, light.
Thirdly, any primary dormancy condition present within the seed must be overcome.
Internal processes leading to removal of primary dormancy is collectively known as
‘after-ripening’ and result from the interaction of the environment with the specific
primary dormancy condition. After-ripening requires a period of time and sometimes
specific methods of seed handling. Even in the absence of primary dormancy and/or if the
seeds are subjected to adverse environmental conditions, a secondary dormancy can
develop and further delay the period when germination takes place (Hartmann et al.,
1990).
2.4.7 Dormancy of Seeds
Seeds which do not germinate when placed under conditions normally considered ideal for germination are said to be dormant. Or dormancy is a condition whereby seeds placed under the environment normally considered ideal for germination fail to germinate
(Hartmann et al., 1990). There are different types of dormancy: primary dormancy,
(innate, inherent, natural, endogenous), secondary (enforced) and induced types of dormancy. 30
2.4.7.1 Types of Seed Dormancy
Innate/primary dormancy is that type with which the seed is shed. It is developed during
maturation on the parent plant and persists for a variable length of time after the seed has
been shed (Hartmann et al., 1990). Enforced dormancy is that which occurs when the
seed is not itself dormant but fails to germinate due to adverse environmental conditions;
however, when conditions become favourable the seeds would germinate (Hartmann et
al., 1990). There is also Induced dormancy also referred to as secondary dormancy and it
is a condition where a non-dormant seed acquires dormancy. It is induced in seeds by a
particular climatic or environmental condition and will persist even after the inductive
conditions are passed and the environment has become favourable for germination
(Hartmann et al., 1990).
2.4.7.2 Causes and Methods of Breaking of Dormancy
There are five causes of seed dormancy, these are: impermeability of the seed coat to
water and oxygen; undeveloped/immature embryo; by chemical inhibitors- e.g. Abscisic acid (ABA); absence of certain hormones- e.g. Cytokinins and gibberellins; lack of special requirement for light or temperature (Hartmann et al.,1990).
Some of the simple and widely used methods for breaking seed dormancy are described in the following section. These include, impaction, scarification, stratification, leaching, and by the use of chemicals. Impaction involves the shaking of the seeds to remove the strophcolor plug (which is cork-like) from the strophcolor cleft. The strophcolor plug blocks the cleft and disallows water and oxygen entry. An example is the seeds of Albizia
31
spp. Scarification is any process of breaking, scratching, mechanically altering, or softening the seed coverings to make them permeable to water and gases (Hartmann et al., 1990). Scarified seeds are more susceptible to injury from pathogenic organisms, however, and will not store as well, comparably, as non-scarified seeds.
Chipping hard seed coats by rubbing with sandpaper, cutting with a file, or cracking with
a hammer are simple methods useful for small amounts of relatively large seeds. For
large-scale mechanical operations, special scarifiers are used. Small seeds of legumes,
such as alfalfa and clover, are often treated in this manner to increase germination. Seeds
may be tumbled in drums lined with sandpaper or in concrete mixers, combined with
sand and gravel. The sand or gravel should be of different size from the seed to facilitate
subsequent separation. Scarification should not proceed to the point at which the seeds
are injured. To determine the optimum time, a test lot can be germinated, the seed coats
may be soaked to observe swelling or the seed coats may be examined with a hand-lens.
The seed coats generally should be dull but not so deeply pitted or cracked as to expose
the inner parts of the seed (Hartmann et al., 1990). Seeds with hard coverings may be
germinated by any method which artificially breaks or marks the seed coat, provided
another type of dormancy is not present. In nature softening the seed coat comes about
through agencies of the environment: mechanical abrasion, alternate freezing and
thawing, attack by micro-organisms in the soil or passage through the digestive tract of
birds or other animals. For effective seed coat decomposition, the seeds must be held
moist at warm temperatures in the soil. Addition of nitrates to the medium could increase
seed softening, presumably because it stimulates fungus activity (Hartmann et al., 1990).
32
One of the environmental conditions affecting germination is water (Hartmann et al.,
1990). Imbibition of water is the first step in the germination process. The most important
factors which affect water uptake by seeds are the nature of seeds and its coverings, and
the amount of available water in the surrounding medium. Seeds have great absorbing power, owing to their colloidal nature. In storage, seeds can absorb moisture/water from the surrounding air. Different kinds of seeds vary greatly in the amount and rate of water absorbed, in storage or during germination. The rate of water uptake is also influenced by temperature, favouring an increased rate. The seed covering also plays an important role in water uptake. In some seeds, it is so impermeable to water that germination will not occur until the seed covering has been altered in some manner.
Soaking seeds before planting is sometimes utilized to initiate the germination process and to shorten the time required for seedlings to emerge from the soil. Seeds which are hard and dry, therefore slow to germinate, may be given such a treatment, but if the seeds ordinarily germinate without difficulty, there is little need for soaking. Seeds which have imbibed water are easily injured and more difficult to plant (Hartmann et al., 1968).
Prolonged soaking can result in injury to the seed, and reduce germination. These
harmful effects have been attributed principally to the presence of micro-organisms and
to poor aeration although there seems to be other effects that are not well understood. If
soaking is to be prolonged, the water should be changed at least every 24 hours
(Hartmann et al., 1990).
33
2.4.8 Pests and Diseases of Chrysophyllum albidum
Chrysophyllum albidum is rarely grown as a sole crop hence there is a dearth of information on the pests and diseases problems associated with the crop (Adelaja, 1997).
For convenience, this subject has been looked at in three different perspectives, namely: at the nursery stage, on the field and post-harvest.
In the nursery the pests and diseases which attack the seedlings are:
(i) Fusarium root rot which is caused by Fusarium sp. The fungus attacks the
roots but in the later stages of growth, other parts of the plant become infected.
(ii) The Grasshopper (Zonocerus variegatus), the insect would defoliate young
seedlings and eat terminal buds, barks and young branches and may result in total
loss of seedlings.
(iii) The leaf eating beetles, which also eat barks and buds of the tree.
(iv) Rodents - The germination in Chrysophyllum albidum is apical and the
cotyledon is highly relished by rats and they also cut back emerging seedlings
(Adelaja, 1997).
There are pests and diseases which also occur on the field. Chrysophyllum share a lot of pests and diseases complex with other members of Sapotaceae, citrus, mango, and
Irvingia. The nature of the damage caused may be direct or indirect. The direct damage occurs when the pests and diseases affect plant parts and reduce yield. The indirect damage occurs when there is a reduction in crop quality. The major field pests and diseases include the scale insects. Most of these insects fall into the following categories.
These are Fluted Scales (Margorodoidae), Soft Scale (Coceidae), Armoured Scale
(Diaspididae), Mealy bugs (Pseudococcidae), the fruit-piercing moth and Anthracnose.
34
Scale insects extract plant sap and can inject toxins into the plant system. They
abundantly excrete honey dew on which the sooty-mould fungus develops. Trees become
black and the radiation assimilation surface is greatly reduced. The tree vigour is reduced.
Species may show some preference for certain organs of the plant. However, the attack
is rather diffuse and all parts of a tree are generally infested. Severe attacks cause
discolouration of leaves, kill branches, may deform small fruits and be the principal cause
of fruit shedding. The moths pierce into both ripe and unripe fruits while feeding and at
the same time introduce some toxins into the fruit. Toxins hasten the senescence of
infested fruits and are aborted in large numbers. This is perhaps one of the most
important problems of Chrysophyllum in Nigeria. Another field disease is Anthracnose
which is caused by Collectotrichum sp. The symptoms include dieback of green twigs,
spots on leaves, distortion and short hole, lesions on the leaves. In a severe attack the
spots on the fruits result in decay. Fruit fly stings enhance fungus entry ( Adelaja,1997).
2.4.9 Post–Harvest Pests and Diseases of Chrysophyllum
Post-harvest pests and diseases are very damaging on fruits. These are caused by Fruit flies (Diptera) and the rot causing bacteria (Erwinia sp.). These will cause fruits to rot and prevention is difficult especially in bruised fruits. The nature of the Chrysophyllum tree (some higher than 36 m) makes pests control difficult and expensive. Chemical control is usually risky and less desirable. Therefore it is proposed that a biological pest control strategy should be introduced (Adelaja, 1997).
35
2.4.10 Post-Harvest Handling and Treatment
It has been discovered that fruits and leafy vegetables demand careful attention at every
stage from before/after harvest, through to consumption, if product quality is to be
achieved and maintained. Star apple fruit is one of the indigenous fruits that present
special problems of both transport and preservation, because they are generally more perishable than most exotic fruits, under tropical conditions of high temperature, high moisture and numerous pests and diseases which attack the succulent mesocarp of the fruits. It is this attack by pests and diseases in addition to improper post-harvest handling
of fruits that aggravate the quick deterioration commonly observed in this fruit (Adebisi,
1997).
In reducing fruit loss in the market, the following are suggested important factors, which
affect post-harvest losses. These include:
• Initial quality of the fruit: Fruits should be allowed to reach maturity stage before
embarking on their harvest.
• Temperature: Mature harvested fruits must be kept under ambient temperature or
room temperature, as too much heat may encourage spoilage of the fruits.
• Relative Humidity: Harvested fruits also must be kept away from humid
environment.
• Chemical treatment: The use of chemical treatment should be restricted to the use
of simple organic chemical, like Neem Extract Water (NEW). Experience from
those who are involved in star apple business is that they have not been using any
chemical to treat the tree nor the fruits after harvest. They only use brooms and
leaves to drive away flies.
36
• Sorting and grading: The farmers who harvest these fruits readily sort-out the
damaged fruits while harvesting but do not grade them into various sizes before
taking them to the market. Different sizes are put together in a basket and sold as
such to buyers. This contributes a lot to the post-harvest losses. The buyer, after
buying would then separate the bigger ones from the smaller ones. The consumers
prefer the bigger fruits to the smaller ones. This means the retailers are left with
the smaller ones which are not sold. Those left unsold start deteriorating after a
few days and are eventually disposed off.
• Heat treatment: Chrysophyllum albidum may not necessarily need heat treatment
as long as the harvesters allow the fruits to mature and ripen on the mother trees
before harvesting.
• Packaging: Star apple fruits need improved methods of packaging. Experience
has shown that, the way the farmers pack too many fruits into large containers, is
seriously affecting transportation efficiency from the villages to the rural and/or
urban centres, for sale. Transporters charge high fares because of this method. It
will be advantageous if these fruits are packed in smaller quantities, in small
containers or baskets. This will go a long way to improve post-harvest handling of
the fruits (Adebisi, 1997).
A study has indicated that majority of our indigenous fruits are climacteric (fruits remaining unripe on mother trees even when matured) ones; including Irvingia gabonensis and Dacryodes edulis. As most of these fruits are damaged before reaching their final destinations to the consumers when fully ripened, Ladipo, (1997) observed that
37 holding these fruits in an unriped condition before getting to the consumer may be a critical strategy for the success of any local (rural and national) or international export programme. Observing the Chrysophyllum albidum fruit, one may want to prescribe this same treatment for it. However, unlike some exportable fruits like pineapple, its marketing potential is still within a domestic trade corridor and may not need long storage strategy (Adebisi, 1997).
2.4.11 Uses of Chrysophyllum albidum
The branches are good source of fuelwood – charcoal, firewood. The stem can be harvested as timber and can also be used in carving doors. The gummy latex of the bark and fruit is used as bird-lime; chew gum, and also used in the treatment of wounds- it closes up the wound when it is applied to the wound for early healing. Fruits are commonly used as snack/desert. The fruit can serve as raw material for the manufacturing industries. It can also be used in the preparation of wine, spirits and soft drinks, jam and jellies (Umelo, 1997). It also contains 90% anacardic acid which serves as a source of resin used industrially to protect wood. It has the highest content of ascorbic acid with 1000---3330 mg of ascorbic acid per 100 g of edible fruit or about 100 times that of oranges and 10 times in guava or cashew (Asenjo, 1946). It is also an excellent source of vitamins, iron, and flavours to dye (Bada, 1997; Umelo, 1997). The endosperm is also rich in oil. The oil is extracted and used in making soap and other products.The cotyledons are also useful in the preparation of medicine for the treatment of infertility problems in both male and female; infertility due to oligospermia in males
38
and infertility due to presence of abnormalities within the uterus and female tubes;
abdominal pains in dysmenorrhea; secondary ammenorrhea in women
(loss or absence of menstrual cycle) (Olapade, 1995). Again, it can be used in the
preparation of ointments for the treatment of some dermatological and vaginal infections.
The seeds, along with those of other Sapotaceae, are used as anklets in dancing (hence
Ashanti name “Akasaa”). In the Iboland, in Nigeria, the tree is worshipped, as it is
believed to confer fertility on barren women (Bada, 1997).
The leaves are also used as emollient for the treatment of skin eruptions (Idowu et al.,
2003). The bark is also used in the preparation of medicine for the treatment of fever and
black –coated tongues called efududu in Yoruba (Olapade, 1997). It is used as a remedy
for yellow fever and malaria (Idowu et al., 2003).
The leaves are prepared and used as body massage which activates the nerves for better sexual performance and become very useful in the treatment of frigidity in women and depressed libido in men (Olapade, 1995)
39
CHAPTER THREE
MATERIALS AND METHODS
3.1 Selection of Study Area
The area chosen for the study includes eight communities in the Akuapem North District,
namely: Nyamebekyere, Tinkrong, Adawso, Bewase, Asempaneye, Kabu, and Konko,
Saforo (fig 3.1). These are among the communities where the Chrysophyllum albidum
(Africa/ White Star Apple) trees are found growing successfully as a backyard tree crop
in association with other agricultural crops or on the farm. This study examines the
agroforestry potentials of the tree and the gains of its products to the communities in the
Akuapem North District.
3.2 Description of the Study Area
The study area lies roughly within latitudes 5° 30´´ N and 7° 30´´ N , and longitudes 0°
30´´ W and 1° 30´´ W. The area is located in the south-eastern part of the Eastern Region of Ghana, and falls under the jurisdiction of the Akuapem North District. It is about 450 sq.km in size and about 58 km from Accra (Gyasi and Quarcoo, 1978; Sarfo-Mensah,
1994; Min. of Agric, undated). The Akuapem North District shares boundaries with the following districts: Yilo-Krobo in the north-east, New Juabeng in north-west, Dangbe
West in the south-east and Akuapem south in the south-west. Some of the boundary towns of the district include Obosomase, Mangoase, Okorase, Asaman/Onyamebekyere,
Akyeremateng, Kwamateng, Akoni No. 1 and Larteh (Min. of Agric, undated).
40
Fig 3.1: A Map showing the study area
Akuapem North District
Source: Ashanti Regional Survey Department, 2011
41
3.2.1 Relief and Drainage
There is one main hill range. That is, the Akuapem range. The highest is between 1,250 ft
(381 m) and 1600 ft (487.7 m). The highest point is at Amonokrom which is about 1,642
ft (500 m). The district can be divided physically into two: the ridge which is semi-urban
and the lowland area which is rural. The lowest point is about 500 ft (Min. of Agric,
undated).
The study area has the Brump, Ponpon and Aponapong and their tributaries forming the
main drainage channels for the Larteh-Mampong area. The Aboabo, Nkasi and Yensi
streams drain the North West zones (Min. of Agric, undated). Recently, though, climatic
changes and the effect of improper land-use practices along the catchment areas and
banks have resulted in the drying up of these major rivers in the dry season (Owusu,
1993; Sarfo-Mensah, 1994).
3.2.2 Vegetation
The vegetation of the area is between moist semi-deciduous south east zone and dry semi-deciduous inner zone. Almost all of which through man’s activity (especially shifting cultivation), has now been reduced to broken forests on most hill tops, and
secondary forest on slopes and valleys. In some areas too, particularly along the motor
roads, and main foot paths, the forest has degenerated into scrubs and bush. Thickets are
also found on the slopes facing the Accra Plains (Gyasi and Quarcoo, 1978; Sarfo-
Mensah, 1994; Min. of Agric, undated). The remaining vegetation, containing only a few remnants of the commercially valuable species of timber (example: wawa, odum, and
42 mahogany) appears to be more extensive in the southern portions than the Northern portions of the study area (Gyasi and Quarcoo, 1978; Sarfo-Mensah, 1994; Min. of Agric, undated). The result of degradation of the vegetation through man’s activity has been depletion of the soil, scarcity of wood for fuel, lack of fodder for animals (especially during the dry season) and the disappearance of trees, shrubs and other plants which are important sources of medicine for the people (Owusu, 1990; Sarfo-Mensah, 1994).
Land degradation is becoming a serious threat in the study area because of inefficient agricultural management practices, cutting of trees for fuel wood, bushfires, etc. (Owusu,
1993; Sarfo-Mensah, 1994). According to the local people, the different types of land degradation common in the area include: soil erosion, woodland and rangeland degradation, declining soil fertility and pollution of water bodies. The accelerated land degradation in the study area could partly be due to the undulating nature of the land. It could also have been the result of strategies to provide survival needs of the people mostly for food, building materials and fuel wood. For example, according to the local people, fuel wood was not a commercial commodity a few decades ago. It was usually collected from communal land by consumers for household purposes. Currently, it has become a tradable commodity. Poor household in some communities (example:
Korkormu and Kwamoso) use cassava stumps and raffia branches to meet their energy needs (Sarfo-Mensah, 1994).
43
3.2.3 Soils and Climate
The soils are mostly sandy clays and loams which are deemed suitable for the cultivation of both food and tree crops (Gyasi and Quarcoo, 1978; Sarfo-Mensah, 1994; Min. of
Agric, undated). Increase in population in the study area has led to an increase in demand for land and the shortening of fallow periods and consequently, severe degradation of farm sites (Owusu, 1990; Sarfo-Mensah, 1994). This, according to the local people, has resulted in poor soil fertility. The study area experiences a bi-modal or double maximal rainfall centred in May to September or November. The seasons are separated by two relatively dry periods. The minor dry season is in August, whilst the major dry season is from December to February (Min. of Agric, undated). The area experiences a moderately high mean temperature of 23.9 0C (75 F) and an average rainfall of 1270 mm (50 in) per annum (Min. of Agric, undated).
3.2.4 Population, Ethnicity and Economic Activities
According to the population census (2000), the Akuapem North District has a population of 68,247 in 1970 which is growing at an annual rate of 1.6%. This increased by 24.7% to
85,131 in 1984 and 2000 at 1.8%. The current population figure is 104,753, made up of
48,942 males and 55,811 females. About 25% of the total population live in the urban area which is located on the ridge. About 53.3% of the population are women. The population density of the district is about 225 people per kilometer square (sq.km) (Min. of Agric., undated). The district’s population is made up of various ethnic groups. At the moment the local dialects spoken by the people of the district include Twi, Akuapem,
44
Kyerepong and Guan. There are some Ewes too in some of the communities who are farmers. Majority of the alien population are Togolese (Gyasi and Quarcoo, 1978).
As found in other rural areas of Ghana, the economic activity engaged in by the majority of the people in the study area is agriculture, especially food-crop farming. Farming practices are traditional and rain-fed. With this traditional system, land rotation / bush- fallowing is practised. The land is left to fallow for three to six years in order to regenerate its fertility after a period of cultivation (Gyasi and Quarcoo, 1978; Owusu,
1990). Farm sizes are small. About 77% of farmers cultivate 1.2 ha a year. Only 2% of the farmers cultivate 2 ha a year (Sarfo-Mensah, 1994; Min. of Agric., undated). Mixed cropping is widely practised. Mechanized farming is only possible around Kwamoso and
Okrakwadwo areas where large tracts of government land are leased to farmers and can support the investment in mechanized farming (Min. of Agric., undated). The district was one of the first centres in the economic development of Ghana. It was one of the first centres of cocoa industry where cocoa was produced commercially. Currently, soil impoverishment, mass bushfire of 1983, and diseases have virtually wiped out the industry and led to mass movement of farmers, westwards and northwards to the rich forest lands of the Akims and the Ashantis, respectively (Min. of Agric., undated).
Another aspect of farming is the area of land tenure system. The land is family-held by the indigenous Akuapems. However, with increasing population pressure and the presence of a large number of immigrant farmers, it has led to the evolution of ‘share cropping’ on tenancy arrangement (‘abunu’ and ‘abusa’) and a system of rental or leasing
(Gyasi and Quarcoo, 1978; Sarfo-Mensah, 1994).
45
A limited number of livestock such as fowls, goats and sheep are kept usually on a free- range basis. Other economic activities include: trading, hunting, basket weaving, cassava processing, palm oil extraction, distillation of “akpeteshie” (local gin) and wood carving
(Gyasi and Quarcoo, 1978). Poultry and piggery are done intensively down the ridge in the villages whilst cattle, sheep and goats are kept on the ridge by farmers. The major poultry and piggery producing areas are Mampong and Adukrom (Min. of Agric. undated). The district has also a huge potential for developing aquaculture. Currently, about 60 ponds exist mainly around Mampong-Nkwanta valley and Abonse areas with major fishes like tilapia, cod and catfish being produced (Min. of Agric., undated).
3.3 Study Methodology and Data Collection
The study was carried out in three parts namely, a socio-economic survey, biological survey, and sensory evaluation of food products developed from C. albidum fruit pulp.
Data used in this study was obtained from two main sources: primary and secondary. The primary sources involved field survey and experimentation. The secondary sources included a review of existing literature on the study area in relation to the district, region and the nation as a whole.
3.3.1 Socio-economic Survey
Three approaches were used in conducting the study in the area chosen. These were:
• Exploratory/Familiarization visit, Reconnaissance Survey and Socio-economic
Survey (questionnaire administration).
46
• An exploratory and familiarization visit was taken to Koforidua, the Eastern
Regional capital from where most traders/ sellers in Kumasi claim to buy the
fruits of the ‘White Star Apple’ (Chrysophyllum albidum). The purpose of the
visit was to make enquiries into the areas where the trees are found growing and
to identify them.
• Another day was spent carrying out a Reconnaissance Survey in the study area.
The objectives of the survey were five-fold; these were:
• To identify areas where many of the trees are found growing.
• To identify possible towns from where samples were to be taken for the actual
survey.
• To establish rapport/contact with some farmers in the towns where the actual
survey was to be carried out.
• To rapidly appraise some of the main biophysical and socio-economic features in
the area, and
• To take pictures of the trees.
The survey was conducted in some towns in the Akuapem North District. The towns
included: Tinkong, Adawso, Asempaneye, Bewase, Kabu, Konko, Nyamebekyere, and
Saforo, The direction of the reconnaissance and the area for the study are shown in the
map. A contact farmer for each village was chosen. During the survey 49 tree owners
were identified using the snowball-sampling technique. In other words, a farmer after the
interview would direct the researcher to another tree owner. Originally, the plan was to interview 100 respondents from five towns. However, during the survey exercise, it was
47
discovered that the number of tree owners in the five towns were not even up to 50
therefore three other towns were added to the five as guided by the tree owners.
Key biophysical (nature of soil, important trees, etc) features of the area were rapidly
appraised. Another visit was also paid to Akropong (the district capital) for the collection
of general information on the study area. For uniformity, a structural questionnaire
/interview guide was used to obtain information on the socio-economic characteristics of
farmers/ tree owners. The interview guide contained items which were mainly close- ended, where respondents were given many alternate responses from which they had to choose only one option. However, a few of the items were open-ended questions where the respondents were free to express their views or opinions. The survey instrument, developed after the reconnaissance survey, considered questions under personal characteristics of respondents, household characteristics, management practices carried out in the growing of C. albidum, marketing and income or the gains from the
Chrysophyllum albidum trees they own.
3.3.2 Experiments to determine germination percentages
Fruits which were purchased were depulped and the seeds extracted. The seeds were pre- treated for sowing. Those seeds which were soaked in water for six days had the water changed daily to ensure that leached-out chemicals from the seeds do not accumulate in the water to affect the germination process. There were seven treatments with three
replications. In all the experiments, two hundred and ten seeds were sown. Thirty seeds
were sown in polythene bags filled with ordinary garden soil for each treatment having
three (3) replicates. These were kept on a veranda under a roof and were watered daily
48 for some weeks. The design used was Completely Randomised Design (because the seeds were sown in a controlled environment and provided with the same environmental conditions). The different treatments are described in Table 3.1.
Table 3.1: Treatments for the germination test experiment
Treatment Description
T1 Seeds sown fresh (control)
T2 Seeds soaked in water for 8 days
T3 Seeds soaked in hot water (100 0 C) for 1
T4 hour
Seeds cracked and soaked in water
overnight
T5 Seeds soaked in water for 10days
T6 Seeds soaked in water for 12days
T7 Seeds cracked and sown
3.3.3 Initial Growth Rate Experiments (Growth Parameters)
The seeds which were given the pre-germination treatments were sown in polythene bags containing ordinary garden soil. The seeds included: T1 (sown fresh), T2 (soaked in water for 8 days), T3 (soaked in hot water 100 C for 1 hour), T4 (cracked and soaked in water overnight), T5 (soaked in water for 10 days), T6 (soaked in water for 12 days) and
T7 (cracked and sown fresh). Three months after sowing the seeds, their initial growth rates were taken to determine the effects of pre-germination treatments on the growth of
49 the seedlings. The initial growth parameters taken were plant height, length and breadth of leaves and number of leaves.
3.3.4 Proximate Analysis of Fruit, Leaves and Seeds
Chrysophyllum albidum fruit pulp, leaves and seeds weighing 1.00 g each were taken to the Soil Research Institute of CSIR, Kwadaso in Kumasi for proximate analysis .This was done to determine the nutrient status of the fruit, seeds and leaves and also appraise the nutritional potential of the fruits, seeds and leaves.
3.3.5 Food Product Development
Sensory evaluation on the eleven food and drink products developed was conducted to assess score for selected attributes including appearance, taste, flavour, aroma, texture mouthfeel and overall acceptability, using questionnaires. Twenty four students and a teacher from the Home Economics Department of Juaso Senior High School assisted in the evaluation.(These were specially chosen because they were familiar with the preparations of such food products and so could give a better judgement, and only one teacher from the department was chosen for the assessment because the other teachers were engaged with the supervision of the final year students’ practical examination .) A
7-point Hedonic Scale ranging from "Disliked Very Much (DVM)"to "Like Very Much
(LVM) was employed (Table3.2)
50
Table 3.2: Hedonic Scale of Sensory Evaluation
Hedonic Scale Sensory Evaluation
1 Dislike Very Much (DVM)
2 Dislike Moderately (DM)
3 Dislike Slightly (DS)
4 Neither Like Nor Dislike (NLND)
5 Like Slightly (LS)
6 Like Moderately (LM)
7 Like Very Much (LVM)
Food and Drinks Prepared
Paste made by blending the fruit pulp weighing 250 g was used to prepare various food products in April, 2006. The food products developed included pastries and drinks. Some of the food products included cakes, rock buns, chips, cheese straw; drinks included, one made from the fruit pulp only, drink from a mixture of the fruit pulp and ginger, and drink prepared from orange juice. The control products were prepared to make efficient comparison between the two main groups of products for better evaluation of the products. Questionnaires were administered for the sensory evaluation of the products.
Methods for the preparation of the various food products and a sample of the questionnaire can be found at appendix1.
51
3.4 Data Analysis and Analytical Tools
Data collected from the socio-economic survey using questionnaire were coded and
analyzed using SPSS (Special Package for Social Science) version 12.0 windows, a
computer application software. The data were analyzed using descriptive statistics and
the results presented using frequencies, percentages and graphs.
The numbers of seeds which germinated after the pre-germination treatments of the seeds
were calculated using percentages. Data collected on the initial growth of the seedlings
which were: height of seedlings, length of leaves, breadth of leaves and number of leaves
were statistically analyzed using MSTATS. This involved analysis of variance and mean
separation using Duncan’s Multiple Range Test (DMRT) where significant differences
existed among the treatment means.
Nutritive value of the fruits, leaves and seeds were analyzed at the laboratory, using
proximate analysis. Sensory evaluation (organoleptic test) of the food product developed
from the fruit was carried out using the 7- point Hedonic Scale, which ranged from
Disliked Very Much to Like Very Much (LVM).
3.5 Limitations of the Study
Initially, attempts were made to get as many as one hundred respondents in the five (5) sampled communities for interview. It was not possible owing to the fact that only a few people have the trees in the various villages sampled for the study. Instead, the number of villages sampled was increased to eight (8). People are willing to plant the trees but the
52 problem of getting the seedlings prevented them. This however, did not undermine the representativeness of the sample interviewed since in all the villages sampled for the study, all the tree owners were interviewed. But in all the villages the gains of the trees were similar.
53
CHAPTER FOUR
RESULTS
4.1 Characteristics of Respondents
Eight towns within the Akuapem North district were surveyed. A total of 49 tree owners were interviewed in all the eight towns. Kabu had the highest number of tree owners of
14 (28.6%) followed by Nyamebekyere with 9 (18.4%) tree owners. Saforo had the least
number of tree owners, 1 (2 %) as shown in Figure 4.1.
5, 10.2% 4, 8.2% Adawso 1, 2% Asempaneye Bewase 8, 16.3% Kabu 9, 18.4% 3, 6.1% Konko Nyamebekyere
2, 4.1% 14, 28.6% Saforo Tinkong
Figure 4.1: Towns surveyed and the number of tree owners interviewed
Source: Field Survey, July/August 2005
*Population figures are headcount
54
4.1.1 Age Distribution of Respondents
The mean age of farmers was about 49 years. Majority of the tree owners; 20 (40.8%) were 61 years and above. The age groups 41 -50 years and 51 – 60 years had the same number of tree owners of 8 (16.3%). The age group 20 – 30 years representing the youth had the least number of tree owners of 4 (8.2%). It is also important to note that the middle-age group and the oldest group form the bulk of the tree owners indicating that the youth do not grow the trees. Even what the middle-age people own was inherited from their parents/grandparents. This indicates how they still find it difficult to propagate the tree. The observations are presented in figure 4.2.
4, 8.2%
20 - 30 yrs
20, 40.8% 9, 18.4% 31 - 40 yrs 41 - 50 yrs 51 - 60 yrs 8, 16.3% 61 yrs -
8, 16.3%
Figure 4.2: Age distribution of tree owners.
Source: Field Survey, July/August 2005
55
4.1.2 Educational Level of Respondents
The level of education among respondents was generally low, that is, the largest proportion of about 59.2% of the sampled tree owners have had education only up to the middle school level. Table 4.1 shows the educational level of the tree owners sampled in the surveyed communities.
Table 4.1: Level of education of tree owners interviewed
Level of education No. of tree owners % of tree owners
Illiterate 8 16.3
Primary 9 18.4
Middle/JHS 29 59.2
SHS/Trg Col/Voc 3 6.1
Total 49 100
4.1.3 Ethnicity
The Akans, mostly the Akuapems (the indigenous people) constitute the majority of the
tree owners in the sampled communities. None of the respondents from other ethnic
groups claimed to be a tree owner even though some have migrated to settle and farm.
Ethnicity as the determinant of access to control and ownership of a tree was observed to
be important to the study area. This suggests that the ethnicity of the people in the study
area affects their investment in tree planting activities to improve and increase their
resource base especially land tree resources. This is partly explained by the complex land
56
and tree tenure in the study areas as well as the short-term production outlook of many migrant farmers.
4.1.4 Land Ownership and Size of Farm Holdings
Twenty two plots (43.3%) of all holdings are between 4.5 and 5 acres. Very few holdings are large over 5 plots (6.3%). The predominance of small holdings does not encourage commercial farming as most respondents are subsistence farmers. The reasons for the small sizes are mainly tenurial and economic. The small holdings may indicate that since the land owned by C. albidum farmer belonged to the family in most cases, they may not be permitted to grow these trees on a large scale for themselves using the communal/family land. The situation has come about because of the traditional inheritance and population pressure resulting in land scarcity in the study area. The traditional inheritance as observed, leads to fragmentation when farmers desire to provide each of several heirs with land of similar quality.
Most of the respondents indicated that they inherited the C. albidum trees from their
parents/grandparents. Most of the trees are even older than the owners who are between
31-49 years.
Majority of the trees are 45 years. Only a few of the C. albidum trees are less than 15
years according to the respondents. The tree takes a longer period to grow and fruit, and
two respondents indicated that according to their father, those who plant the trees would
die before the tree bears fruit which was a superstition. The fact is that the tree can take
seven or more years as a gestation period depending on the soil and the environmental
factors (Bada, 1997).
57
4.1.5 Number of C. albidum trees owned by Respondents
Most farmers had 10–12 trees (table 4.2). The highest number owned by one farmer was
12. The least was one tree. Most of the farmers wished they could plant more than they have because of the additional income obtained from the sale of the C. albidum fruits but the difficulty in cultivating the tree serves as a factor which prevented them from increasing the number of trees they had.
Table 4.2: Number of C. albidum trees owned by respondents
No. of C.a trees owned No. of tree owners % No. of tree
owners
1 – 3 11 22.4
4 – 6 15 30.6
7 – 9 4 8.2
10 – 12 19 38.8
Total 49 100.0
Source: Field Survey, July/August, 2005
4.1.6 Marketing Strategies of Fruits
The owners do not have any problem with the marketing as most of them negotiate with the wholesale buyers long before the fruits are ready to be harvested. For the marketing of the fruits, the majority of respondents; 37 (75.5%) (Table 4.3), mentioned that wholesalers buy fruits on trees, harvest and sell them in bulk to other market women at
58 urban centres for retailing. At the market, some market women also sell in bulk to other retailers. In some cases, the owners take the fruits to the urban centres and sell them in bulk to retailers.
Pricing at the farm gate is done according to the size and number of fruits on each tree.
Sometimes the wholesalers take advantage of the rural farmers who do not know how to determine the price of the fruits to make maximum profits.
A few of the producers who are familiar with the current price for the fruits at the urban centres harvest and take them to the centres to sell in order to maximize their profits.
The women harvest the fruits and convey them to the marketing centres using cane baskets. This is because, they perceive these as the best since it has good ventilation/or provides good aeration for the fruits and does not permit the generation of heat as this could cause the fruits to deteriorate faster. As soon as the fruits are harvested, they are transported to prevent them from getting rotten. When the fruits begin to show signs of deterioration, the sellers are offered lower prices than if they were fresh. During harvesting, some of the fruits crack. The cracked ones are normally sorted out in order to grade and price as required. The cracked ones are sold quickly and cheaply to avoid further deterioration. The sellers mentioned, that five days after harvesting, the fruits begin to deteriorate. But from the research observation, if they are kept in the refrigerator/ deep freezer, they do not go bad. In the fridge, it can stay whole for at least about one month. In this case, if the traders can get any cold storage facility, it can be of help to them. There are some customers who buy them in smaller quantities and export to the
European countries to sell. They are able to do so by keeping them in the fridge on arrival in the United Kingdom.
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Table 4.3: Marketing strategies of fruits by tree owners
Mode of marketing fruits No. of tree % tree owners
Owners
Owners harvest them and sell them 4 8.2
to wholesale buyers
Owners harvest, transport & sell 8 16.3
them in bulk to wholesale buyers
at the market
Total 49 100.0
4.2 Cumulative Mean Daily Germination
The highest initial germination number was recorded for seeds soaked for 8 days, treatment (T2), which started on the 6th day after sowing with 2 seeds germinating.
Germination of seeds which were soaked for 12 days, (T6) also started on the 7th day with 1 seed. The seed under control treatment (T1) started germinating on the 12th day after sowing with an initial number of 1 seed. Seed germination under Hot Boiled Water
(T3) was however completely inhibited; therefore no data is presented for this treatment.
Seeds cracked and soaked overnight (T4) started germinating on the 8th day with 1 seed.
Seeds that were cracked and soaked in water overnight started germinating 8 days after sowing with 1 seed. Germination of seeds which were cracked and sown directly (T7) started 11 days after sowing with 1 seed. The seeds which were soaked for 10 days (T5) also started germinating 20 days after sowing with 11 seeds. The days to last germination
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value within 30 day period for the various treatments were as follows: T1=23; T2=25;
T4=16; T5=23; T6=14; T7=18
Table 4.4 Mean Percentage Germination of C. albidum Seeds
Treatment Number of seeds that germinated Percentage
T1 23 76.7 T2 25 83.3 T3 0 0 T4 16 53.3 T5 23 76.7 T6 14 46.7 T7 18 60
4.3. Initial Growth Rates of C. albidum Seedlings
The initial growth rates of the seedlings developed from the seeds subjected to different
pre-germination treatments are shown in Table 4.5
Table 4.5: Effects of pre-germination treatments of seeds on the initial growth rate
of C. albidum seedlings.
Height of Breadth of Length No. of leaves
Treatments seedlings(cm) leaves(cm) of leaves(cm)
T1 29.41 b 3.06 6.10 b 2.02 bc
T2 33.48 a 3.25 7.07 a 2.12 a
T4 27.98 b 3.18 7.29 a 2.04abc
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T5 29.90 3.05 6.75ab 1.97 bc
T6 27.11 b 3.02 6.18 b 2.08 ab
T7 28.21 3.18 6.74ab 2.06 ab
SE 3.6 0.04 0.86 0.09
Means bearing identical letters in a column are not significantly different from each
other by Duncan’s Multiple Range Test (DMRT) at 5%.
It could be seen from the results presented in Table 4.5 that seedlings which germinated
under T2 (seeds soaked in water for 8 days) produced the highest height of 33.48 cm,
followed by T5 (seeds soaked water for 10 days) seedlings with a height of 29.90 cm.
Analysis of variance showed that there was significant difference in height between
seedlings from T2 plants and other seedlings which received other treatments. The
ANOVA, however, indicated that no significant differences were observed among the
heights of other seedlings whose seeds were subjected to different pre-germination treatments (F=3.06; P<0.032).
Table 4.6: ANOVA of Height of Seedlings
Source of
Variation SS Df MS F P-value F crit
Treatment 100.7884 5 20.15769 1.31608 0.301418 2.772853
Error/residual 275.6963 18 15.31646
Total 376.4847 23
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It is also clear from Table 4.5 that the mean breadth of leaves of the seedlings whose seeds were subjected to different pre-germination treatments were almost the same.
Despite the observed or apparent differences of mean breadth of leaves, analysis of variance indicated no significant difference (F=2.05; P<0.401).
Table 4.7: ANOVA of Breadth of Leaves
Source of
Variation SS df MS F P-value F crit
Treatment 0.167371 5 0.033474 0.256373 0.930996 2.772853
Error/residual 2.350225 18 0.130568
Total 2.517596 23
The pre-germination treatments, however, had significant effects on the leaf length of C. albidum seedlings. While T4 (seeds cracked and soaked overnight) produced the highest effect on the leaf length with 7.29 cm, T1 ( control) seedlings recorded the least leaf length of 6.10 cm. Analysis of variance showed that the effects produced on leaf length by T2 did not differ from those of treatments 4,5, and 6.
Table4.8: ANOVA of Length of Leaves
Source of
Variation SS Df MS F P-value F crit
Treatment 3.240538 5 0.648108 0.946785 0.475122 2.772853
Error/residual 12.32163 18 0.684535
Total 15.56216 23
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Similarly, the analysis of variance indicated that differences existed on the leaf length of seedlings produced from seeds under treatments 1, 5, 6 and 7. However, there were significant effects on the leaf length of seedlings under treatments 2 and 4 with those of
T1 (control) and T6 (seeds soaked in water for 12 days) (F=2.49; P<0.022).
The number of leaves produced by the seedlings developed from the seeds which received different pre-germination treatments ranged from 2.12 (T2, seeds soaked in water for 8days) to 1.97(T5 seeds soaked in water for 10 days). The results show that the pre-germination treatments given to the seeds have effects on the mean number of leaves produced. Analysis of variance indicated that there were significant differences between the effects produced by T2 and T1 and T5. However, no significant effects were observed among T2, T4, T6 andT7 on the number of leaves produced (F=5.24; P<0.016).
Table 4.9: ANOVA of Number of Leaves
Source of
Variation SS df MS F P-value F crit
Treatment 0.050883 5 0.010177 1.266367 0.320818 2.772853
Error/residual 0.14465 18 0.008036
Total 0.195533 23
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4.4 Proximate Analysis of fruit, leaves and seeds
This was done to determine the nutritive value of the fruit pulp, seeds and leaves and also
appraise nutritional potential of the fruit, seeds and leaves at the Department of the Soil
Research Institute CSIR in Kumasi. The pH of the pulp was 2.87 at 22.8 degree Celsius.
4.4.1 Nutritive value of various parts of Chrysophyllum albidum
Table 4.10 shows the percentages of various nutrient elements in the leaves, seeds and
pulp of fruits of Chrysophyllum albidum. For all the three parts analyzed, the leaves had
the highest values in all the nutrient elements. Apart from % protein, the pulp of the fruits
was rich in the other nutrient elements than the seeds of Chrysophyllum albidum.
Table 4.10: Nutritive value of various parts of Chrysophyllum albidum
Tree part %protein % calcium % magnesium % phosphorus
Leaves 14.88 1.15 0.52 0.061
Seeds 5.82 0.25 0.03 0.034
Fruit(Pulp) Nil 0.65 0.20 0.049
4.5 Food Product Development
The products that were made out of the Chrysophyllum albidum fruit paste included
Chrysophyllum albidum fruit cake, C .albidum rock buns, C. albidum fruit chips-baked/ fried , C. albidum fruit drink, C .albidum fruit and ginger (mixture) drink.
There were some food (pastries) and drinks prepared without the inclusion of C. albidum
fruit paste to compare them with those with the C. albidum incorporated products for the
assessment. These were cakes, rock buns, cheese straw, chips baked/fried.
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Chrysophyllum albidum fruit drink product developed was ranked first, followed by drink
prepared from the mixture of ginger and Chrysophyllum albidum fruit as second and
lastly the orange drink.
Plate 4.1: Some of the pastries prepared with C. albidum fruits
4.5.1 Drinks
The drinks made from the Chrysophyllum albidum fruit and the control (orange) were
evaluated according to their appearance, aroma, texture, mouth-feel, sweetness, aftertaste
and overall acceptability. The results are elaborated below.
Appearance / Colour
With the colour of the product, product 748 (the C. albidum fruit drink only) ranked highest with 54.2 as mean rank value, followed by product 629 (ginger with C. albidum
fruit drink) with 40.3, however, product 857 (orange drink) ranked lowest with a mean value of 19.5 (figure 4.3)
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70
60
50
40
30
20 Mean Rank Mean Rank Score
10
0 748 629 857 Products (Drink)
Figure 4.3: Appearance/colour of products (Drinks)
748 - Chrysophyllum albidum fruit drink.
629-ginger + Chrysophyllum albidum fruit drink
857-orange drink
Aroma of Products (Drinks)
The most preferred aroma of the drinks prepared was product 748 (C. albidum fruit drink only) with a mean rank of 40.7, followed by product 857 (orange drink only) with a mean value of 37.4. However, the least was recorded for product 629 (ginger with C. albidum drink) having the mean value of 35.9 (figure 4.4).
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60
50
40
30
20
Mean Rank Mean Rank Score 10
0 748 629 857 Products (Drink)
Figure 4.4: Aroma of products (Drinks)
Texture of Products (Drinks)
For the texture of the product, product 748 (C. albidum fruit drink only) had the highest mean rank value of 39.4, followed by product 857 (orange drink) having a mean value of
37.5, the least value of 37.0 was recorded for product 629 (ginger with C. albidum fruit drink) (figure 4.5)
60
50
40
30
20
Mean Rank Mean Rank Score 10
0 748 629 857 Products (Drink)
Figure 4.5: Texture of products (Drinks)
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Mouth feel of Products (Drinks)
Product 629 (ginger with C. albidum fruit drink) ranked highest with a mean value of
41.6 for the product mouth feel, followed by product 748 (C. albidum fruit drink only)
with a mean rank value of 39.3, and the least value of 33.0 was recorded for product 857
(orange drink) (figure 4.6)
60 50 40 30 20
Mean RankScore 10 0 748 629 857 Products (Drink)
Figure 4.6: Mouth feel of products (Drinks)
Sweetness of Products (Drinks)
For the sweetness of the products, product 629 (ginger with C. albidum fruit drink) ranked highest with a mean of 42.1 followed by product 748 (C. albidum fruit drink only) with a mean rank of 41.3. Product 857 (orange drink) ranked lowest with a mean of 30.6
(figure 4.7)
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Mean rank
45.00
40.00 35.00 30.00 25.00 20.00 15.00 10.00 5.00 0.00 748 629 857 748 629 857
Figure 4.7: Sweetness of products (drinks)
Aftertaste of Products (Drinks)
Product 748 (C. albidum fruit drink only) ranked highest under product aftertaste with a mean of 39.9, followed by product 629 (ginger with C. albidum fruit drink) with a mean
rank of 38.2, and the lowest recorded for product 857 (orange drink) with a value of 35.8
(figure 4.8)
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60
50
40
30
20 Mean Rank Mean Rank Score
10
0 748 629 857 Products (Drink)
Figure 4.8: Aftertaste of products (Drinks)
Overall Acceptability of Products (Drinks)
For the overall acceptability of products, product 748 (C. albidum fruit drink) ranked highest with a mean value of 43.4 followed by product 629 (ginger with C. albidum fruit drink) also with a value of 41.4. The least mean rank value of 29.1 was recorded for
Product 857 (orange drink) (figure 4.9)
60 50 40 30 20 10 Mean Rank Score 0 748 629 857 Products (Drink)
Figure 4.9: Overall acceptability of products (Drinks)
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4.5.2 Pastries
The pastries made from the Chrysophyllum albidum fruit and the control (cake, rock
buns, chips and cheese straw without the fruit) were evaluated according to their appearance, aroma, texture, mouth-feel, sweetness, aftertaste and overall acceptability.
The results are elaborated below.
Appearance/Colour of Products (Food)
Product 213 (cake without C. albidum fruit) ranked higher with a mean value of 30.7 than product 432 (cake with C. albidum fruit) which also had a mean rank of 20.3. Product
568 (rock buns without the fruit) also recorded a higher mean value of 32.3 than product
771 (rock buns with the fruit) which also recorded 18.7 mean value. Product 299 (chips with fruit fried) recorded 32.1 mean value whereas product 965 (baked chips with the fruit) also recorded a mean rank value as low as 18.9. Product 632 (fried cheese straw) had mean rank value of 30.0 and product 349 (baked cheese straw) recorded mean rank value of 20.9 (figure 4.10)
40 35 30 25 20 15 10 5
Mean Rank Score 0 213 432 568 771 299 965 632 349
Products (Food)
Figure 4.10: Appearance of products (Food)
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Aroma of Products (Food)
Product 299 (chips with fruit fried) recorded the highest mean rank value of 43.3 followed by product 568 (rock buns without fruit) with mean rank value of 31.5. Product
965 (chips with fruit baked) recorded the lowest mean rank value of 17.7. The rest of the observations are presented in figure 4.11.
45 40 35 30 25 20
Mean Rank Score 15 10 5 0 213 432 568 771 299 965 632 349
Products (Food)
Figure 4.11: Aroma of products (Food)
Texture of Products (Food)
Product 299 (chips with fruit fried) recorded the highest mean rank value of 35.1 followed by product 568 (rock buns without fruit) with mean rank value of 30.1. Product
965 (chips with fruit baked) recorded the lowest mean rank value of 15.9. The rest of the observations are presented in figure 4.12.
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Figure 4.12: Texture of products (Food)
Mouth feel of Products (Food).
Product 299 (chips with fruit fried) recorded the highest mean rank value of 34.8 followed by product 568 (rock buns without fruit) with mean rank value of 31.3. Product
965 (chips with fruit baked) recorded the lowest mean rank value of 16.2. The rest of the observations are presented in figure 4.13.
50 45 40 35 30 25 20 15 10 Mean Rank Score Rank Mean 5 0 213 432 568 771 299 965 632 349 Products (Food)
Figure 4.13: Mouth feel of products (Food)
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Sweetness of Products (Food)
Product 299 (chips with fruit fried) recorded the highest mean rank value of 35.5 followed by product 568 (rock buns without fruit) with mean rank value of 32.0. Product
965 (chips with fruit baked) recorded the lowest mean rank value of 15.5. The rest of the observations are presented in figure 4.14.
Figure 4.14: Sweetness of products (Food)
Aftertaste of Products (Food)
Product 299 (chips with fruit fried) recorded the highest mean rank value of 35.7 followed by product 568 (rock buns without fruit) with mean rank value of 33.5. Product
965 (chips with fruit baked) recorded the lowest mean rank value of 15.3. The rest of the observations are presented in figure 4.15.
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45 40 35 30 25 20 15 10
Mean Rank Score Rank Mean 5 0 213 432 568 771 299 965 632 349 Products (Food)
Figure 4.15: Aftertaste of products (Food)
Overall Acceptability of Products (Food)
For the overall acceptability, product 568 (rock buns without fruit) ranked highest with
35.5 and product 771 (rock buns with fruit) also scored 15.5. Product 213 (cake without fruit) also scored 25.8 whereas product 432 (cake with fruit) scored 25.2. Product 632
(fried cheese straw) also had a score of 25.6, but product 349 (baked cheese straw) had a score of 25.4. Product 299 (fried chips with fruit) scored 35.4 whereas product 965
(baked chips with fruit) scored a lowest mean rank of 15.6 (figure 4.16).
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45 40 35 30 25 20 15
Mean Rank Score Rank Mean 10 5 0 213 432 568 771 299 965 632 349
Products (Food)
Figure 4.16: Overall acceptability of products (Food)
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CHAPTER FIVE
DISCUSSION
5.1 Chrysophyllum albidum as a Source of Livelihood for the People
Chrysophyllum albidum tree performs some production and service functions thus serving as a source of livelihood for the people. It provides employment and income for the people by means of the fruits when they are in season. It provides employment for wholesale buyers, harvesters, carriers (porters), truck pushers, drivers, revenue collectors and retailers. This finding supports that of Young (1997) who asserted that fruit trees are managed to meet multiple purposes. The fruits usually ripe and are sold between
December and March. The sale of the fruits during this period helps them to get money to cater for the needs of their families during the Christmas holidays when the expenses of the farmers go up. Some of them also use the proceeds to buy building materials to build their houses, pay their debts, including medical bills and pay school fees of their wards. It can be deduced that, during this period most school children will not owe school fees and this will lead to the smooth running of academic programme as the pupils will not be chased out of the classrooms to go for school fees and other school needs. Therefore, the tree serves as a relief to the people during this time. This result is in consistent with those of Nair (1985) and Young (1997) who reported that agroforestry trees provide multiplicity of products and services for farmers to meet to meet their economic needs.
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Fruits harvested from a single tree could be sold between 50 and 100 Ghana cedis depending on the sizes of the crown and fruits. There are some owners who harvest and transport the fruits to the urban centres to sell. The fruit from one tree could be sold between 200 and 270 Ghana cedis to retailers, thus increasing the profit they obtain from the sales. This confirms the assertion made by Nair (1985) that the other socio-economic advantages attributed to integrated agroforestry production systems include generation of additional employment to the farmers, favourable costs and benefits relations, risk minimization in farming, staggered production of subsidiary farm produce, economic complementarity in the use of inputs and improved nutritive value of diets. Besides the employment and income the trees generate through the fruits, the service functions they provide are numerous. On the farm or homestead where the trees are found growing, they provide shade by its dense crown where animals and people can safely rest. The trees also serve as windbreaks to protect crops and houses, reducing the impact of raindrops on the soil due to its leaves and the extensive root system which is able to check soil erosion in the area. The litter from the tree decomposes and adds organic matter to the soil thereby improving the fertility, structure of the soil, just to mention a few. Therefore the tree is of high socio-economic importance to the people. These findings agree with those of Moore and Ruselle (1990), and Norton (1988) who found in their different studies that agroforestry tree species (such as C.albidum) are used as windbreaks, for soil conservation and for the provision of shade. This is also in agreement with the report made by Nair (1985) that most home gardeners grow a variety of crops together not only to meet their domestic needs, but also as an insurance against risk of monoculture cropping.
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5.2 Germination of Chrysophyllum albidum Seeds
The processes of germination are well documented in Hartmann et al. (1990). The factors that affect germination can be grouped into two main sources. These are internal and external factors. The internal factors include seed dormancy and viability (Roberts,
1972). The external factors also include suitable temperature, composition of gases in the atmosphere, light, adequate water supply (moisture), and soil composition and germination medium. Dormancy can be produced by seed coverings that are impervious to water. In some seeds, this type can preserve the dry seeds for many years even at warm temperature. Germination can be induced by any method that can soften or scarify the covering (Hartmann et al., 1990).
Chrysophyllum albidum seeds have hard protective seed coat. Inside the hard seed coat, the endosperm is also covered with wax-like layer which makes it difficult for seed to imbibe water for germination to start (Boateng and Adu-Yeboah, 2006). This characteristic of the seed is a major reason for its dormancy leading to uneven germination which is a major setback in reforestation programmes using Chrysophyllum albidum seeds. Soaking seeds before planting is sometimes utilized to initiate the germination process and to shorten the time required for seedlings to emerge from the soil. Such a treatment may be advantageous with seeds normally slow to germinate, with seeds which are hard and dry, or when certain dormancy conditions exist (Hartmann et al., 1990).
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According to Hartmann et al., (1990) prolonged soaking can result in injury to the seeds and reduce germination. This harmful effect has been attributed principally to the presence of micro-organisms and to poor aeration although there seems to be other effects as well, that are not understood. The results of this experiment support this fact, since the prolonged soaking of Chrysophyllum albidum seeds in water reduced the rate of seed germination with increasing number of days of soaking. Here the optimal period was
8 days of soaking with daily changing of the water which registered a germination percentage of 85 within 26 days, the first few seeds emerging within 6 days. This was followed by the seeds soaked for 10 days and the control with a percentage germination of 77 within 22 and 25 days respectively. Those seeds soaked for 12 days rather had a low germination percentage of 47 within 19 days. This might be attributed to the fact that the embryo being a living organ was starved of oxygen when submerged under water over a long period. Furthermore, the seeds have had their seed coat softened through imbibition of water and possibly there was loss of soluble nutrients or growth hormones from the seeds.
Mechanical pre- treatments such as removal of seed coat are known to induce faster rate of seed germination than when the seed coat is not scarified before sowing. In the work done by Boateng and Adu-Yeboah (2006), the mechanical scarification of Chrysophyllum albidum seeds near the embryo before sowing showed significantly higher germination percentage of 88.9. However, this must be done to avoid damaging the embryo and thereby wasting the seed. In this experiment, the seeds of Chrysophyllum albidum which were cracked around the circumference had a percentage germination of 55%. This might be attributed to the fact that some of the embryos got damaged in the process of
81 scarification. This means that if mechanical scarification is to be done it must be done in a careful manner to avoid damaging the embryo. The seeds that were soaked in hot boiled water for 1 hour never germinated. The high temperature of 100 0 C and the 1 hour duration definitely might have killed the embryo. Though the seeds which were sown direct (T1) were slow to germinate, T1 had an appreciable germination percentage of
73.3. This means that the regular watering of the seeds in the soil permitted the seed coat to imbibe water as time went by, but the water imbibed at the initial stage was not enough to soften the hard seed coat rapidly to break it so as to allow the plumule and radicle to emerge early enough unlike the pre-treated ones which were soaked in water for a number of days or which were scarified at the circumference. This result confirms those of Hartmann et al., (1990); Goor and Barney (1996) and who reported that seeds with hard coat covering may be germinated by methods which artificially break the hard seed coat.
5.3 Initial Growth Rate of Chrysophyllum albidum Seedlings
The pattern of the number of germinated Chrysophyllum albidum seeds over time did not influence the seedlings growth overtime. C. albidum seedlings tend to have a slow growth rate. Results obtained on the initial growth rate of pre-treated seeds of C. albidum agree with the results of the work done by Bobtoya (2006) on “the effect of pre-sowing treatments on the germination and early growth of Parkia biglobosa (dawadawa) seeds”.
It was reported that the pre-sowing treatments had a significant effect on the germination of P. biglobosa, however, once the seeds had germinated, this influence was hardly seen on the initial growth and development of the seedlings. The results obtained revealed that
82 once the seeds had germinated, the treatments did not have significant influence on the growth of the seedlings. Hence the slight differences in growth rate among the treatments might be due to differences in environmental conditions such as light and as well as physiological processes like the reallocation of plant resources. According to
Mcconnaughay and Coleman (1999), optimal partitioning models and theories suggest that plants respond to variation in the environment by partitioning biomass among various plant organs to optimize the capture of nutrients, light, water and carbon dioxide in a manner that maximizes plant growth rate.
5.4 Proximate Analysis of Chrysophyllum albidum Fruit, Leaves, and Seeds
The results showed that the plant components- fruits, leaves and seeds are highly nutritious. From the findings of this study the fruit has a pH value of 2.7 and that shows that it is highly acidic (ascorbic acid) This also confirms the findings of Asenjo (1946) and wanatca .According to Asenjo (1946) the acidic (ascorbic acid/vitamin C) content of the fruit is very high with 1000 to 3330 mg per 1000 gm and also about 100 times that of oranges and 10 times that which is contained in guava and cashew. According to wanatca, the fruit pulp contains 21.8 mg/100 g ascorbic acid, while the skin contains 75 mg/ 100 g. Nair, (1985) also mentioned that, the most significant attribute of fruit trees that makes them entirely suitable for rural agroforestry is the nutritive value of their products. The fruit, therefore, when eaten can supply vitamin C, phosphorus, calcium, and potassium to enhance the health status of the eater. Again, from the findings of this study, the leaves of the tree are high in protein (nitrogen), as a result when the litter decomposes the soil can be enriched. The leaves being rich in protein (nitrogen) and
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other nutrient elements confirms the assertion made by Osafo (1970) that the tree species
could be used in enrichment planting. This agrees with the findings of the study that C.
albidum tree species can be used in agroforestry for sustainable agricultural production, as the leaves can enrich the soil with nitrogen, phosphorus, potassium and other minerals essential for plant growth and development.
5.5 Food Product Development
From the study C. albidum fruit could be used to prepare food products like drinks and pastries. This confirms findings made by Umelo(1997) and Adisa(2000) that the C
.albidum fruit could be used in the preparation of wine, spirits, soft drinks jams and jellies. The natural colour (orange) possessed by C .albidum fruit pulp is imparted to the drinks prepared from it without using any artificial food colour. According to the results obtained from the products developed from C. albidum fruit, the C. albidum fruit drink
(product748) had the highest mean rank score of 43.4, followed by C. albidum fruit blended with ginger (product 629) scored 41.4 as compared with drink from orange fruit
(product 857) which had the least a score value of 29.1 For the pastries prepared with C. albidum the fruit .the fried chips with fruit (product 299) scored 35.4 and ranked higher than fried cheese straw (product 632 ) with the score of 25.4. This shows that in the preparation of cheese straw C. albidum fruit can be used to replace the cheese favourably for better results.
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5.6 Agroforestry Potential of C. albidum
The prevalence of C. albidum indicates that it is an important fruit tree in the rainforest and forest zones but the very low density of it confirms that its extinction is near, if new ones are not planted. The information on utility indicates that the greatest impact in improving the status of C. albidum would be by exploiting its value as a fruit tree This
agrees with the assertion made by Ulzen-Appiah and Fiawatsor (2000) that fruit trees in
agroforestry have environmental and socio-economic benefits Responses from the
farmers suggest that they are interested in intensifying C. albidum for cash. To achieve
this, farmers need to change from their current use of wildings to sourcing their materials
from formal nurseries, which produce seedlings of improved varieties. Such nurseries are
rare currently, but they inevitably develop in response to demand–pull, when the
breakthrough in the seed germination is made known to them so that the farmers or
people who would like to make nurseries of them can do so and sell the seedlings.
5.6.1 Nitrogen Inputs and Soil Improvement
According to Young (1997) nitrogen–fixing trees can make substantial contributions to
nitrogen inputs There are also some non-legume tree species like Casuarina equisetifolia which can fix amounts of the order 50-100 kg N per hectare per year (Young, 1997).
Though C. albidum tree species is not a leguminous plant, the leaves have high content of
nitrogen,(14.88%) as discovered from the study. It can therefore enhance the nitrogen
status of the soil when the leaf litter decomposes.
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Nitrogen fixation and a high biomass production have been widely recognized as
desirable in agroforestry system. However, many properties are specific to particular
objective of a system in which the trees are used. The properties which are likely to make
a woody perennial suitable for soil fertility maintenance or improvement include: a high
rate of leafy biomass and the existence of deep roots. Trees are therefore, able to absorb
water and nutrients from the layers lower than the topsoil to ensure efficient utilization of
water and the nutrients which would otherwise be not made available to the agricultural
crops. There is also the evidence of high and balanced nutrient content in the foliage; and
litter of high quality (high in nitrogen, low in lignin and polyphenols) (Eastham et al.,
1994; Young, 1997).
C. albidum is an evergreen tree rarely shedding all its leaves in any one season except
when the tree is dead or under serious stress (e.g. pest/disease attacks). It follows that
thick layer may not accumulate under the tree more so the leaves are of a texture that
would enhance rapid mineralization. There is a belief that the rapid mineralization of the
limited litter would improve the quality (fertility, etc) of the top soil of the undergrowth
(Bada, 1997). From the study, C. albidum plants have been found to grow successfully with other agricultural crops or other fruit trees, like plantain and cocoa, respectively, from the study. C. albidum tree species is not invasive. This is because when the mature ones produce fruits, in most cases, the fruits fall and split open or decay for the seeds to germinate under the very canopy of the tree. They do not grow to cover /scatter the whole land area unlike Leucanena leucocephela (which is also an agroforestry species but have
some other desirable qualities). Besides, an agroforestry tree species apart from having
86 the above qualities should have production functions, or service functions other than the soil improvement ability (Young, 1997). This is exactly what pertains to C. albidum.
87
CHAPTER SIX
CONCLUSIONS AND RECOMMENDATIONS
6.1 Conclusions
The main findings of the study were:
Most of the farmers own between 10 and12 of C. albidum trees. The fruits could be sold by farmers to earn income. The income generated from the sale of the fruits is used to pay school fees and to supplement household budget during the dry season when the fruits ripen.
C. albidum seeds will not germinate readily due to seed dormancy which must be broken.
Therefore, a method like artificial scarification such as soaking seeds in water for some time before sowing or cracking the seeds before soaking in water promotes early germination of the seeds. Seeds which were soaked in water for 8 days germinated earlier than other seeds subjected to other pre-germination treatments.
Pre-germination treatments of the seeds have effects on the initial growth of the plant height leaf length and the number of leaves produced by the seedlings. Seeds soaked in water for 8 days produced the highest plant height of 33.48 cm, and the higher number of leaves, 2.12. Seeds cracked and soaked in water overnight produced the highest effects on length of leaves with 7.29 cm growth 3 months after sowing.
The leaves, seeds and pulp of the fruit of C. albidum contain nutrients such as protein, minerals like calcium, magnesium and phosphorus.
88
C. albidum fruits can be used to prepare drinks and pastries thereby adding value to the
fruit which deteriorates very fast. Of the entire food product developed the drink from the
fruit pulp had the highest overall acceptability value of 43.4.
6.1.1 The implication of the results
The above results shows that C.albidum has a potential to be used as an indigenous tree for agroforestry in Ghana as it can serve as a sources of food, income and windbreak.
Efforts should therefore be made to exploit its potential to the fullest as it is currently being under utilized. Means of integrating C. albidum tree species into the agricultural production system should be sought so as to make significant contribution to sustainable agriculture, which aims at meeting the ever –increasing needs of mankind. Farmers need to be educated on the potential of C. albidum as an agroforestry tree species and encouraged to adopt scientific processes in the management and growing of the tree species.
Chrysophyllum albidum is a promising but currently under- exploited tree of the forest zone and more especially in the Akuapem North District of the Eastern Region.
Chrysophyllum albidum tree species is a multipurpose tree species which can be utilized in agroforestry. It is both environmentally and economically beneficial.
It is entirely beneficial because it has a continual plant cover as an evergreen tree species which rarely shed all its leaves, unless it dies or under severe environmental stress. For the broad leaves it possesses, with the dense canopy, it is also able to harvest and utilize incoming solar radiation which might otherwise be lost by seasonally sown plant. It can
89
be utilised as in shelter belts or wind breaks. It has the capacity to enrich the micro site by
depositing litter in the topsoil, which can then be exploited by more shallow rooted
species; and a capacity to modify the micro site, which can bring about favourable effects
on the soil and associated plant species and even animals at the site. The leaf litter
produced and the buttress roots possessed by the tree are also of vital importance so far as
the control of soil erosion is concerned. It is also said to be economically beneficial. This
is because mature bole can be harvested as timber and sold or used as such. The branches
can be used or sold as wood fuel. The tree can produce a lot of fruits which could be sold for money by the owners. In all the areas where the socio-economic survey were conducted, it was realized that the amount of money accruing from the sale of the fruits from one Chrysophyllum albidum tree was comparatively far more higher than all other tree species like cocoa or oil palm. The fruits are also eaten by both young and old and are known to be nutritious, as it contains some amount of potassium, phosphorus, etc. it has also been found to have highest content of ascorbic acid (vitamin C) with 1000 to
3330 mg of ascorbic acid per 100 gm of edible fruit of about 100 times that of oranges and 10 times that of guava or cashew (Asenjo, 1946). Besides the above uses of the fruit, it can also be used in the manufacturing of soft and strong drinks, jelly, jam, and even in pastries as experimented in the study, and many others.
Indeed, the Chrysophyllum albidum tree species is multipurpose in function. Farmers are willing to own more than the number they own now because it is economically viable, socially accepted, and environmentally sound, when planted (Bene et al., 1997). Some have the trees growing on their farms or homestead together with the agricultural crops.
90
The major constraint of the farmers who own these trees and are willing to plant more is
the difficulty of germinating the seeds. Now that this study has been able to come out
with how to enhance the germination of seeds of Chrysophyllum albidum, which can
even be undertaken by the unskilled person or farmer, there is a great breakthrough for
the farmers or prospective agroforesters who would like to use them as agroforestry
species.
Nonetheless, like all other woody components in the agroforestry system, offsetting the
benefits are strong plant competitive attributes, such as the capacity to shade under-storey plants, and a tendency to dominate the water economy at the micro site. The strong neighbour effects of Chrysophyllum albidum reported in this study indicates the need to select trees with small compact canopies without compromising fruit yield or quality.
6.2 Recommendations
The socio-economic survey study should be conducted again to cover large population and all other towns where the trees are found growing in the country and the pre- germination treatment of the seed to enhance germination should include chipping of the seed coat, and satisfaction.
Full domestication of this valuable fruit tree would be more beneficial. Therefore, the positioning and management options studies should be carried out to obtain the full potentials of this species. The proximate analysis should also involve nutritional content of different parts of the plant.
Other areas that desire further studies on Chrysophyllum albidum include: development of some products from the fruits, vegetative propagation, (marcotting, etc), post- harvest
91
and marketing studies. Chrysophyllum albidum in multi-strata system, optimum tree
population, tree arrangement, possibilities of tree manipulation (pruning, topping, etc.),
and increased utilization of the tree in agroforestry systems for sustainable agriculture
may also be considered.
Chrysophyllum albidum in multistrata system, optimum tree population, tree arrangement possibilities of tree manipulation (pruning, topping, etc.) and increase utilization of the tree in agroforestry systems for sustainable agriculture should be reconsidered.
92
REFERENCES
Abbiw, D.K. (1990). Useful Plants of Ghana: West African uses of wild cultivated
plants. ITP/Kew 337p
Adebisi, A.A. (1997) Post-Harvest and marketing constraints of C. albidum in Nigeria.
Proceedings of a National Workshop on the Potentials of Star Apple in Nigeria,
CENTRAD, Pp 84-86.
Adelaja, B. A. (1997) Observations on the Pests and Diseases of Chrysophyllum albidum in Nigeria .In: Proceedings of National Workshops on the potentials of the Star Apple in
Nigeria, CENTRAD Nigeria, pp 117-120.
Adewusi, H.A., (1997). The African Star Apple (Chrysophyllum albidum) indigenous knowledge (I K) from Ibadan, Southwestern Nigeria, Proceedings of a National
Workshop on the Potentials of the Star Apple in Nigeria (eds) Denton O A, Ladipo D.O,
Adetoro M.A. Sarumi M B, CENTRAD Nigeria pp: 25-33.
Agbleze, G., Anane, J.F., Owusu, D., Ulzen-Appiah, F. (2002) In:Agroforestry in Ghana,
A Technology Information Book. Africa 2000 Network, Ghana.
Asenjo, C.F., 1946. The high ascorbic acid content of the West Indian Charry. Science,
103: 219.
Aubreville, A. (1963) Flora du Gabon. Paris Museum National D’Histoire Naturelle No.3
Aubreville, A. (1964) Flora du Cameroun. Paris Museum National D’Histoire Naturelle.
93
Bada, S.O. (1997) Preliminary information on the ecology of Chrysophyllum albidum G.
Don, in West and Central Africa, In : Proceedings of a National Workshop on the
Potentials of the Star Apple in Nigeria CENTRAD Nigeria Ibadan.
Beentje, H. (1994) Kenya trees, shrubs and lianas. National Museums of Kenya, Nairobi.
722p.
Bene, J.G., Beall, H.W. and Cote, A. (1977) Trees, Food and People –Land Management
in the Tropics. IDRC, Ottawa.
Beniest, J. (2001) Agroforestry, In Crop Production in Tropical Africa. Brussels; Goekint
Graphics. 1227-1243.
Boateng, S. K. and Adu -Yeboah, E (2006) Preliminary Studies on the Germination of
the African Star Apple (C. albidum) seeds. Technical Report CSIR-PGRC, Bunso Ghana.
Bobtoya, S. (2006) Effect of Pre-sowing Treatment on Germination and Early Growth of
Parkia biglobosa (dawadawa) Seeds. B.Sc Thesis, Faculty of Renewable Natural
Resources, KNUST, Kumasi, Ghana. Pp 50.
Bowen, G.D., Sanginga, N. and Danso, S.K.A. (1990). Biological nitrogen fixation in agroforestry- an overview. Transactions of the 14th International Congress of Soil
Science 3, 170-175.
Budelman, A. (1989b). The performance of selected leaf mulches in temperature
reduction and moisture conservation in the upper soil stratum. Agroforestry Systems 8,
53-66, 1989
94
Dommergues, Y.R. (1987). The role of biological nitrogen fixation in agroforestry. In:
Steppler and Nair, P.K.R. (1987), q.v. pp: 245-271
Eastham, J., Scott,P.R. and Steckis, R. (1994) Components of the water balance for tree species under evaluation for Agroforestry to control salinity in the wheat belt of Western
Australia. Agroforestry Systems.
Gbile, Z.O. (1997) Taxonomy of the African Star Apple (C. albidum) and related species
In : Proceedings of a National Workshop on the Star Apple in Nigeria, CENTRAD,
Nigeria, 11-12pp.
Goor, A. Y. and Barney, C. W. (1976) Forest tree planting in arid zones (2nd Ed.) Ronald
Press, New York.
Gyasi, E.A. and Quarcoo, B.A. (1978) “The Environment of the Mampong Valley Social
Laboratory”. In Schott, J.R. ed. An Experiment in Integrated Rural Development. The
Mampong Valley Social Laboratory in Ghana. International Institute of Rural
Reconstruction (IIRR). New York, pp 69 -77.
Hartmann, H. T. and Kester, O. E. (1990). Plant Propagation, Principles and Practices.
Prentice-Hall, Inc. Eaglewood Cliffs New Jersey 702 pp.
Hawthorne,W. D. (1990) Field Guide to the Forest Trees of Ghana. Natural Resources
Institute/Overseas Development Agency. pp 56 – 65.
Hawthorne,W.D. (1995) Ecolgical Profiles of Ghanaian Forest Trees. ODA Tropical
Forest Papers. No. 29 pp 80 – 82.
95
Hutchinson, J. and Dalziel, J.M. (1963) Flora of West Tropical Africa Vol.1.
Huxley, P.A. (ed) (1983) Plant Research and Agroforestry. ICRAF, Nairobi, Kenya.
Ibironke, G.G., Olaleye, S. B., Balogun, O. and Aremu, D. (1997). Effects of diets containing seeds of Garcinia kola (Herkel) on gastric acidity and experimental ulceration in rats. Phytotherapy Research, Vol. 11, 312-313.
Idowu, T. O., Onawunmi, G.O., Ogundaini, A.O., Adesanya S.A. (2003) Antimicrobial constituents of Chrysophyllum albidum seed cotyledons. Nig. J. Nat. Prod. And Med.
Vol. 07, 2003.
Irvine, F.R. (1961) Woody Plants of Ghana, Oxford Univ. Press, London.
Kafuru, E. (1994) Immense help from nature’s workshop. ISBN 978-3217-0-0212
Kantende, A B.; Birnie, A. and Tengas, B. (1995). Useful Trees and Shrubs for Uganda;
Regional Soil Conservation Unit RSCU/ SIDA, Nairobi, Kenya.
Keay, R.W.J., Onochie, C.F.A. and Standfield, d.P (1964). Nigerian Trees Vol.II. Federal
Department of Forest Research, Ibadan.
Keay, R.W.J. (1989) Trees of Nigeria. Claredon Press, Oxford.
Kemp, R.A., (1975c). Seed Pretreatment and principles of nursery handling. Forest Seeds
Collection and Handling. 2: 35 – 39.
King, K.F.S. (1979) Agri-silviculture (The Taungya System) Bull. No.1, Dep. For.,
Ibadan.
96
Ladipo, D. O. (1997) Marketing and Post-harvest constraints of Traditional Vegetables in Sub-Saharan Africa. Paper prepared for NRI-IPGRI International Workshop on
African Indigenous Vegetables, Limbe, Cameroon 13-18.
Leakey, J. (1996). Definition of agroforestry revisited. Agroforestry Today, Jan –
February 1996. Vol.8, No 1.
Leakey, R.B.B. (1994) ‘Cinderalla’ tree species …… the clock strikes eleven.
Agroforestry Today 6 (2): 2
Lundgren, B. (1992) Introduction [Editorial].Agroforestry Systems 1, 3-6.
Lundgren, L. and Lundgren, B. (1979) Rainfall, interception and evaporation in the
Mazumbai Forest Reserve, West Usambara Mountains, Tanzania and their importance in the assessment of land potential. Geografiska Annaler 61 A, 157-178
Macoboy., S. (1989) Trees for fruit and foliage. Laudowne Press, New York. p 45
Mayer, A. M. and Poljakoff-Mayer, A. (1963) The germination of seeds. McMillan co.
New York. pp 31-60.
Mcconnaughay, K.D.M and Coleman, J.S. (1999) Biomass Allocation in Plants:
Ontogeny or Optimality? A Test Along Three Resource Gradients. Available at
www.findarticles.com/planticles/mi_2121/is_8_80/ai_58517872. Accessed on 8th
February, 2006.
Ministry of Agriculture (undated) District profile, Akuapem North District.
97
Moore, R. and Russell, R. (1990) The ‘three north’s’ forest protection system- China.
Agroforestry Systems 10, 71-88.
Nair, P.K.R. (1979) Intensive Multiple Cropping with Coconuts in India: Principles,
Programmes and Prospects. Berlin (West) Verlag Paul Parey.
Nair,P.K.R. (1985) Classification of Agroforestry Systems. Agroforestry Systems. 3: 97 –
128.
Norton, R.L.(1988)Windbreaks: benefits to orchard and vineyard crops. In: Brandle and
Hintz (1988) q.v. pp. 205-213.
Okafor, J.C. (1981) Woody plants of nutritional importance in traditional farming
systems of the Nigerian humid tropics. Ph.D. Thesis, University of Ibadan, pp 178 – 185.
Okafor, J.C. and Fernandes, E.C.M. (1987). Compound farms of south-east Nigeria: a
predominant agroforestry homegarden system with crops and small livestocks.
Agroforestry Systems 5: 1534-168.
Olapade, E.O. (1995) Foods and herbs for Diabetes Milletus and Hypertension. Narl
Specialist Clinic, Ibadan, Nigeria. ISBN: 978-33595-0-9.
Olapade, E.O. (1997) Medicinal Importance of Chrysophyllum albidum. Proceedings of
National Workshop on the potentials of Star Apple in Nigeria, CENTRAD,Nigeria.
Opeke, L.K. (1982) Tropical tree crops. John Willey and Sons, NY. 312pp.
Oppong, S.K. (2002) Agroforestry in Ghana, A Technical Information Book. Africa 2000
Network, Ghana. 98
Osafo, E.D. (1970) The Development of Silvicultural Techniques Applied to Natural
Forests. F.P.R.I. Technical Note No. 13.
Owusu, D.Y (1990) “Experience with Agroforestry” ILEA Newsletter Vol. 6 No 2pp 8-
10.
Owusu, D.Y. (1983) “Farm-based Agroforestry: Four years of Experience in Ghana”.
Agroforestry Today Vol. 5 No. 1 pp 8 – 10.
Quashie-Sam, S.J., Dunn, J., Dampson, J.A., Minnae, S. and Avilla, M. (1990)
Agroforestry Potentials and Research for the land use systems in the humid lowlands of
Ghana. AFRENA Report, No. 34
Rhoades, C.C. (1997) Single – tree influences on soil properties in agroforestry lessons
from natural forest and savannah ecosystems. Agroforestry Systems 35, 71 – 94.
Roberts, E. H. (1972) Viability of Seeds. Chapman and Hall Ltd, London.
Sanginga, N. and Mulongoy, K. (1995) Increasing biological Nitrogen fixation and its
contribution to the N cycle in alley cropping. In: Kang et al. (1995), q.v: pp. 90-102.
Sarfo – Mensah, P. (1994) Analysis of some Socio-Economic Factors that Affect the
Adoption of Agroforestry Technologies in the Yensi Valley in Akuapim, Ghana. M.Sc.
Thesis.
Sofowora, A. (1993). Medicinal plants and Traditional medicine in Africa. Spectrum
Books Limited, Ibadan. (285), Nigeria.
99
Sommers, P., (1978) Traditional Home Gardens of selected Philippine Households and
their Potential for Improving Human Nutrition. M.Sc .Thesis, UPLB. Los Banos ;
University of Phillipine.
Steentoft, M. (1988) Flowering Plants in West Africa. Cambridge University Press
(Printed in Grt. Britain at the Bath Pres Avon).
Tomar, V.P.S., Narain, P. and Dadhwal, K.S. (1992) Effect of perennial mulches on
moisture conservation and soil-building properties through Agroforestry. Agroforestry
Systems 19, 241-252.
Treben, M. (1986) Health through gods pharmacy-advice and experience with medicinal
herbs, Ennsthaler Austria, p. 88.
Tweneboah, C.K. (2000) Modern Agriculture in the Tropics; with special reference to
Ghana Food Crops. Wood Publishers.
Umelo, R. (1997). Potentials for utilization of Agbalumo (Yor.). (Chrysophyllum
albidum) for jam making in Nigeria. Paper presented at the C. albidum development
Workshop. CENTRAD. Ibadan, Nigeria.
Ulzen-Appiah, F. and Fiawatsor, B. (2000). Fruit Trees in Agroforestry. In: Agroforestry
in Ghana, Africa 2000 Network.
Vandenbeldt, R.J. (1990) Agroforestry in the semiarid tropics. In: MacDicken, V. (1990), q.v.: pp. 150-194.
100
Wood, P.J. and Burley, J. (1991) A Tree for All Reason: the introduction and Evaluation of Multipurpose Trees for Agroforestry. ICRAF, Nairobi.
Young, A. (1989a) Agroforestry for Soil Conservation. CAB International, Wallingford,
UK.
Young, A. (1997) Agroforestry for soil management. CAB International Wallingford,
UK.
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APPENDICES
Appendix 1: Questionnaire for Socio-economic Survey
KWAME NKRUMAH UNIVERSITY OF SCIENCE AND TECHNOLOGY
COLLEGE OF AGRICULTURE AND NATURAL RESOURCES
(FACULTY OF AGRICULTURE AND NATURAL RESOURCES)
DEPARTMENT OF AGROFORESTRY
A. PERSONAL CHARACTERISTICS
1. Name …………………………………………………………
2. Age ………………………
3. Marital status: Single ( ) Married ( ) Widow/Widower ( )
4. Level of education:
5. Religion: None ( ) Christian ( ) Moslem ( ) Tradition ( ) Others (specify)
………………………….
6. Family house: a. Self-owned ( ) Rented /Hired ( )
7. What building materials used, and why………………………………………
I. Mud house with thatch roof ( )……………………………………………
II. Mud house with bamboo roof ( )…………………………………………
III. Mud house with iron/aluminium roof ( )…………………………………
IV. Land-crate block with bamboo roof ( ) …………………………………
V. Land-crate block with iron/aluminium roof ( ) ………………………… 102
V. Concrete block with iron/aluminium roof ( ) ……………………………
8. What facilities are in the house?
Radio ( ) Tape recorder ( ) TV ( ) Fridge ( )
Deep freezer ( ) others (specify) ………………………………
9. a. Ownership of farmland:
Family ( ) Outright purchase ( ) Shared cropping ( )
Lease ( ) Hiring ( ) others (specify) …………
b. Are you able to farm the land owned?
If no, why? ………………………………………………………
C. OCCUPATIONAL CHARACTERISTICS
10. What is your major occupation?
I. Crop farming ( )
II. Livestock production ( )
III. Public/Civil servant ( )
IV. Trading ( )
V. Artisan ( )
VII. Others (specify) ……………………….……………………………
D. FARM MANAGEMENT CHARACTERISTICS
11. What production system do you practice, and why?
a. Land rotation ………………………………………………………………
b. Permanent field cultivation …………………………………………………
103
c. Pastoral farming ……………………………………………………………
d. Agroforestry …………………………………………………………….....
e. Others (specify) ……………………………………………………………
12. Indicate which of the following your land is set aside for:
I. Gardening: Yes ( ) No ( )
II. Tree growing: Yes ( ) No ( )
III. Fallow management: Yes ( ) No ( )
IV. Home garden: Yes ( ) No ( )
13. If fallow management is practiced, how long is the fallow period? …………
14. What is the total number of farms owned? ……………………………
DISTANCE
FARM SIZE AGE OF FARM FROM HOME
1
2
3
4
5
15. What are the major problems of farm management with regard to?
a. Soil fertility…………………………………………………………………
b. Availability of land ………………………………………………………
c. Destruction of stray animals ………………………………………………
d. Bushfire ……………………………………………………………………
104
e. Others (specify)………………………… ……………………………….
16. List the crops you grow in order of importance.
YIELD
CROP TYPE SIZE 1kg/ha ( ), bag/ha ( ), bskt/ha
( )
1
2
3
4
5
17. Which of these crops gives you most food for the family? (List in order of importance)
1 ………………………… 4
…………………………………………………
2 ………………………… 5
…………………………………………………
3 ………………………… 6
…………………………………………………
18. Have you heard about agroforestry? (i) Yes ( ) No ( )
19. If yes from whom / which organization?
105
I. MOFA
II. NGO
III. MEDIA
IV. MOFA & MEDIA
V. NGO &MEDIA
VI. MOFA &NGO
VII. ALL
20. Do you grow or leave trees on your farm? (i) Yes ( ) No ( )
21. Why? ………......
If yes, which type of trees do you grow or leave on your farm? ……………
22. Why do you have ‘Alasa’/ ‘Akasaa’ trees growing in your farm?
………………………
Reasons:
i. To provide additional income ( )
ii. To check soil erosion ( )
iii. To prevent the ripping off of the house roofs ( )
iv. To provide shade ( )
v. To provide fuel wood ( )
vi. To provide the fodder for livestock ( )
vii. Others (specify) ………………………………………………
23. Do you have erosion on your farm / home compound? (i) Yes ( ) No ( )
24. What causes it?
Rain water
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Wind
Run water and wind
Slope of land
Construction of road
No well planned drainage systems
25. Who cultivated the ‘Alasa’ trees?
a. Parents ( ) b. Grandparents ( ) c. Farmer ( ) d. Children
26. How old are the ‘Alasa’ trees you own?
I. 0-5
II. 6-10
III. 11-15
IV. 16-20
V. 21 & above
27. Which of the different species of trees you own gives you the most income?
I. Orange
II. Oil palm
III. Timber species
IV. Alasa
V. Cocoa
28. How many ‘Alasa’ trees have you?
I. 1-3
107
II. 4-6
III. 7-9
IV. 10-12
V. More than 12
29. If you have less than ten, why? Give reasons
I. Difficult in propagation
II. Scarcity of land
III. Growers die before tree begins to fruit
IV. I did not know its value
30. If you have more than ten, why? Give reasons
I. To get more income
II. For medicine
III. Others
31. Would you like to own more of the ‘Alasa’ trees than you have at the moment?
i. Yes ( ) ii. No ( )
32. How did you cultivate the ‘Alasa’ tree?
a. Seed nursed
b. Wildlings used
c. As voluntary crop
108
d. A&B
33. Do you encounter any problems with its cultivation? Yes ( ) No ( )
34. Which of the problems do you encounter with its cultivation; and how are you able to overcome them
PROBLEMS SOLUTIONS / CONTROL
I. Germination
( )
II. Diseases
( )
III. Pests
( )
IV. Bushfire
( )
V. Theft
( )
VI. Poor soil
( )
VII. Others
(specify)
109
E. How long do these stages occur after sowing the seeds?
STAGE DURATION SEASON
1-17,DAYS 18-20,
35. Germination 21-30, 31-40,
OTHER
1-2 MONTHS
36. Flowering 3-4
5-6
1-2 MONTHS
37. Fruiting 3-4
5-6
1-2 MONTHS
38. Ripening 3-4
5-6
1-2 MONTHS
39. Harvesting 3-4
5-6
40. Which crop do you grow in association with the ‘Alasa’ tree?
I. Cocoa
II. Plantain
III. Cassava
IV. Oil palm
V. Maize
110
F. List how you spend your income from the sale ‘alasa’ in order of importance and the percentage spent on each.
41. PURPOSE 42. PERCENTAGE (%)
1. To defray a debt ( ) I.10-20
2. To pay children’s fee ( ) II. 21-40
3. To build a house ( ) III. 41-60
4. To buy personal effects (name IV. 61-&ABOVE
them) …………….... ( )
5.To save at the bank ( )
6.To expand a farm ( )
7.To provide health-care facilities
8. To fend for the food needs of the
family ( )
9.To use as capital in trading ( )
10. Others (specify) ……… ( )
43.In all, how much did you obtain from the sale of the ‘Alasa’ fruit?
………………………………...
44. How do you carry out these processes: harvesting, storage and marketing?
Harvesting methods Methods of storage
I……………………...... I ......
111
II.……………………...... II......
III……………………...... III......
IV...... ………………...... IV......
V……………………...... V......
VI...... ………………...... VI......
45. How do you market the fruits?
a. Owners harvest them and retail them to consumers at the market.
b. Owners harvest them and sell them to middlemen / women.
c. Owners harvest, transport and sell them in bulk to middle women at the market.
d. Middle women buy fruits on trees, harvest and transport them to the marketing
centers and retail
e. Middle women buy fruits on trees and sell them in bulk to other market women
for retailing.
46. How do you price the fruits?
i. Price according to the size of fruit on trees.
ii. Price according to the number of fruits on trees.
iii. Measure in containers and price.
iv. Fruits are counted after harvesting and priced.
47. Which containers are used in conveying the fruits?
112
a. boxes
b. buckets
c. baskets
d. bags
e. trays
48. Which of these containers is the best and why?
Best container …………………………………………………..
49. Reason
………………………………………………………………………………………
………………………………………………………………………………………
………………………………………………………………………………………
50. Do you prune the branches of the ‘Alasa’ trees? Yes ( ) No ( )
51. If yes, why
I. To allow air circulation
II. To get bigger fruit size
III. To get rid of pest mistletoe
IV. To allow easy harvesting of fruit
V. To prevent tree shade on other plant
52. If no, why
I…………......
II………......
III………………......
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53. Have you been taught how to prune the trees? Yes ( ) No ( )
54. If yes, which group / organization?
55. If yes, which tool do you use in pruning? ………………………………......
56. And how is the pruning done? ………………………………………………
57. What has been the effect of pruning the trees?
a. Bigger fruit sizes are produced.
b. Incidence of pests is reduced.
c. Incidence of disease is reduced.
d. Shape of trees look beautiful.
e. Increase in number of fruits.
f. Parts of the branches die.
g. Decrease in yield.
58. If pruning is done, what do you use the prunings for?
i. fodder ( )
ii. mulching ( )
iii. fuel wood / charcoal ( )
iv. medicine ( )
v. poles for building houses (shelter) ( )
vi. cash ( )
vii. left on soil to decay and enrich the soil ( )
viii. others (specify)………………………………………………………
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59. What other objectives and goals of your household are satisfied by owning the
‘Alasa’ trees?
a. Generation of income and favorable cash flow? ( ) d. Security / collateral ( )
b. Conservation and increase in resources base? ( ) e. Others? (Specify)
……
c. Recognition and acceptance in community? ( )
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Appendix 2
Table 2: No. of Seeds germinating on a particular day after sowing C. albidum seeds
Days after Treatments
sowing
T1 T2 T3 T4 T5 T6 T7
5 0 0 0 0 0 0 0
6 0 2 0 0 0 0 0
7 0 0 0 0 0 1 0
8 0 2 0 1 0 0 0
9 0 0 0 0 0 0 0
10 0 0 0 0 0 0 0
11 0 1 0 0 0 0 1
12 1 0 0 0 0 0 1
13 0 0 0 2 0 0 1
14 2 0 0 1 0 0 2
15 0 0 0 0 0 0 0
16 0 0 0 0 0 0 0
17 7 0 0 1 0 11 9
18 5 7 0 0 0 1 0
19 3 11 0 10 0 1 2
20 1 0 0 1 11 0 1
21 1 0 0 0 8 0 0
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22 3 0 0 0 0 0 1
23 0 1 0 0 2 0 0
24 0 0 0 0 0 0 2
25 0 0 0 0 0 0 0
26 0 1 0 0 2 0 0
27 0 0 0 0 0 0 0
28 0 0 0 0 0 0 0
29 0 0 0 0 0 0 0
30 0 0 0 0 0 0 0
Table 3: ANOVA of Height of Seedlings
Source of
Variation SS df MS F P-value F crit
Treatment 100.7884 5 20.15769 1.31608 0.301418 2.772853
Error/residual 275.6963 18 15.31646
Total 376.4847 23
Table 4: ANOVA of Diameter of Leaves
Source of
Variation SS df MS F P-value F crit
Treatment 0.167371 5 0.033474 0.256373 0.930996 2.772853
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Error/residual 2.350225 18 0.130568
Total 2.517596 23
Table 5: ANOVA of Length of Leaves
Source of
Variation SS df MS F P-value F crit
Treatment 3.240538 5 0.648108 0.946785 0.475122 2.772853
Error/residual 12.32163 18 0.684535
Total 15.56216 23
Table 6: ANOVA of Number of Leaves
Source of
Variation SS df MS F P-value F crit
Treatment 0.050883 5 0.010177 1.266367 0.320818 2.772853
Error/residual 0.14465 18 0.008036
Total 0.195533 23
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Table 7: ANOVA of Number of Root Hairs
Source of
Variation SS df MS F P-value F crit
Treatment 1.164888 5 0.232978 0.584255 0.711838 2.772853
Error/residual 7.177675 18 0.39876
Total 8.342563 23
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Appendix 3
Plate 1: The seeds of C. albidum
Plate 2: The fruits of C. albidum
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Plate 3: Seedlings of C. albidum during the pre-germination treatment experiment
Plate 4: A typical C. albidum tree
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