Cashew, from seed to market: a review Bianca Dendena, Stefano Corsi To cite this version: Bianca Dendena, Stefano Corsi. Cashew, from seed to market: a review. Agronomy for Sustainable Development, Springer Verlag/EDP Sciences/INRA, 2014, 34 (4), pp.753-772. 10.1007/s13593-014- 0240-7. hal-01234842 HAL Id: hal-01234842 https://hal.archives-ouvertes.fr/hal-01234842 Submitted on 27 Nov 2015 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. Agron. Sustain. Dev. (2014) 34:753–772 DOI 10.1007/s13593-014-0240-7 REVIEW ARTICLE Cashew, from seed to market: a review Bianca Dendena & Stefano Corsi Accepted: 8 July 2014 /Published online: 30 July 2014 # INRA and Springer-Verlag France 2014 Abstract Cashew is a tropical tree native to South America. Contents Cashew was introduced in Asia and Africa by European explorers in the sixteenth century. The world production of 1. Introduction....................................1 cashew raw nuts reached 4.27 million tons in 2011. Vietnam is 2. Botanicaldescription.............................2 the top producer of raw nuts, and India is the first processor 3. Originanddiffusion............................4 and exporter of processed nuts. The cashew market is expect- 4. Ecology.........................................4 ed to remain strong due to the high growth of production in 5. Agronomicpractices.............................5 some areas such as West Africa. For instance, a 40 % produc- 5.1. Propagation...............................5 tion increase has been observed in Nigeria over the last 5 years. 5.2. Landpreparation...........................5 There is also an increasing exploitation of high-value by- 5.3. Weeding...................................6 products, particularly those made of cashew nut shell liquid. 5.4. Intercropping...........................7 Cashew production is potentially a major value for smallhold- 5.5. Fertilization............................7 er farmers from emerging countries. Despite the relevance of 5.6. Irrigation..............................7 cashew production on the international markets and the po- 5.7. Pestcontrol............................8 tential for boosting rural development and reducing poverty, a 5.8. Pruning...................................8 complete review on cashew is missing. Therefore, we review 5.9. Harvesting............................8 here the cashew production chain. Our main conclusions are 6. Cashew products and by-products: uses and as follows: (1) several management practices, processing processing................................. 8 methods, and uses of products and by-products are published; 6.1. Products..................................8 (2) however, there is still a lack of knowledge due to a 6.1.1. Cashewkernel...................8 scattered research framework lacking integrated research pro- 6.1.2. Cashewapple........ .............. 11 grams; (3) smallholder farmers face major constraints limiting 6.2. By-products......................... ..11 the development of cashew sector locally, ranging from diffi- 6.2.1. Cashewnutshellliquid.............11 cult access to good planting material and training to lack of 6.2.2. Cashewskinextract...............12 investment for innovating processing facilities; (4) among 6.2.3. Cashewshellcake....... .........12 them, women, that account for up to 95 % of the workforce 6.2.4. Cashewbark....... .............13 in the sector, receive lower wages and are subject to worse 6.3. Minorproducts....... ............... .....13 working conditions. 7. Internationalmarketanddevelopment............13 7.1. Implicationsforsmallholderfarmers.........15 8. Conclusions................................16 Keywords AnacardiumoccidentaleL. .Valuechain .Cashew nut . Cashew processing . Smallholder farmers . Development 1 Introduction B. Dendena (*) : S. Corsi Dipartimento di Economia, Management e Metodi Quantitativi Cashew (Anacardium occidentale L.) is a tropical nut tree (DEMM), Università degli Studi di Milano, Via Celoria 2, 20133 Milan, Italy likely native of South America, with Central Brazil agreed e-mail: [email protected] to be the center of origin (Johnson 1973; Nair 2010). After the 754 B. Dendena, S. Corsi introduction of cashew crop to Asia and Africa during the conventional breeding, for which there is still a limited under- explorations of European conquerors, mainly Portuguese, standing concerning vegetative propagation methods, includ- cashew has widely spread becoming a major export commod- ing micro-propagation (Aliyu 2005). Additionally, map-based ity crop for several countries. In 2011, about 4.7 million tons programs are still in their inception phase; thus, more research of raw nuts was produced worldwide, almost equally distrib- is needed to genetically characterize some agronomically uted between Asia and Africa, whereas almost 1.8 million valuable traits. Similarly, there is a wide variety of crop tons over 2 million tons of cashew apples were produced in management techniques, processing methods, and equipment South America, namely, Brazil (FAO 2013a). The growing options that have only been partially tested and investi- interest in cashew crop is shown by the evidence that cashew gated, thus limiting their potential application. Therefore, kernel, the main product cashew is cropped for, is a high-value in order to identify and highlight the major findings as luxury commodity with steadily growing production volumes well as the fields yet to be explored in the research on and sales over the last 20 years (Azam-Ali and Judge 2001; cashew crop, this review was undertaken by adopting a FAO 2013a). Also, there are expectations that the market will value chain approach. Following the methodology of this remain strong for some time due the considerable potential to approach, the entire value chain of cashew crop was the cashew market for high-value by-products, such as cashew thoroughly reviewed by critically analyzing and summa- nut shell liquid, broken nuts, and cashew shell cake rizing peer-reviewed articles, conference proceedings, (Boillereau and Adam 2007). What is more, cashew has been and reports by international organizations. The literature mainly produced in emerging countries where it is both an depicted a fragmented and dated framework that this agricultural commodity that significantly contributes to gross review aims to update and organize. domestic product and export exchanges at the country level and an essential source for the livelihood of smallholder farmers that make up the majority of the producers and pro- 2 Botanical description cessors worldwide (Azam-Ali and Judge 2001; Fitzpatrick 2011). Therefore, the cashew industry plays an important role Cashew (A. occidentale L.) is an evergreen perennial tree plant in the economic development of countries like Vietnam, India, belonging to the family Anacardiaceae. This family is consid- Nigeria, Ivory Coast, and Ghana and should thus be consid- ered to encompass 60–74 genera consisting of 400–600 spe- ered a key contributor to the achievement of the United cies, depending on the classification adopted (Bailey 1961; Nations Millennium Development Goals. Indeed, the cashew Brizicky 1962;Khoslaetal.1973; Mitchell and Mori 1987). industry could be positively exploited in this sense for Among the eight species in the genus Anacardium, only empowering smallholder farmers with a particular focus on cashew (occidentale) is of economic value, due to its edible women, creating revenues and employment opportunities, and hypocarp and nutritious kernel. promoting small- to medium-scale industrialization processes, Plant height varies considerably, ranging from 5 to 14 m. especially in rural areas (Fig. 1). The canopy size also varies up to a width of 20 m. The root Cashew production has been steadily increasing over re- system is usually deep and widespread. The root distribution cent years, which is more down to an increase in the cultivated pattern depends on soil type, planting material and method, area from 1,963,000 ha in 1992 to greater than 5,300,000 ha in age, level of crop nutrition, and irrigation. Upon germination 2011 (FAO 2013a) than an increase in productivity per hect- of the nut, the radicle develops rapidly into a tap root, which are, which almost doubled from 475 to 805 kg/ha in the same further produces laterals. As the lateral roots elongate, fibrous reference period (FAO 2013a). The relatively limited im- roots develop on the tap root. The early developed tap root provement in productivity per hectare can be attributed to system gradually takes up a complex structure of extensive constraints in the improvement of cashew species through roots with considerable lateral and vertical spread, with most Fig. 1 a Farmer showing cashew fruit in the early stage of development in Zambia (©FAO/ G. Thomas). b Women selecting cashew nuts for packing in Sri Lanka (©FAO/G. Bizzarri) Cashew, from seed to market 755 of the feeding roots residing in the surface layer of the soil. In shaped hypocarpium deriving from the enlargement of the shallow