Cashew Nut

Description

Cashew nut is scientifically known as Anarcadium occidentale, and locally known as Mkorosho, or Mkanju (Swahili) in the coast region. The crop originated from the Northern part of South America. The Portuguese introduced cashew nut to Mozambique where it flourished forming extensive forests; and eventually spread to the East African region. In Africa, this crop has spread for over 500 years either naturally or through smallholder cultivation. In Kenya, cashew nut has traditionally been grown along the coastal region and primarily in Kwale, Mombasa, Kilifi, Tana River and Lamu counties. Recently, cashew production was introduced in Taita Taveta and Tharaka Nithi Counties and the crop has proved to be doing well in those areas. In that regard, the crop has the potential to thrive in other non-traditional counties owing to its resilience to adverse climatic conditions. The cashew nut plant is a fast growing tree that grows to a height of 10-12m tall. Its trunk is often irregularly shaped. The leaves are spirally arranged, leathery textured, elliptic to obviate, 4 to 22cm long and 2 to 15cm broad, with a smooth margin. The flowers are produced in a panicle or corymb up to 26cm long, each flower is small, pale green at first then turns reddish, with five slender, acute petals 7 to 15mm long. The nut is attached to the lower portion of the cashew apple, which is heart like or conically shaped. The cashew nut (seed) hangs at the bottom of the apple and is c-shaped or kidney shaped. The tree has an estimated economic life span of at least 45 years

Cashew nut requires hot temperatures of between 24oC and 28oC but can thrive even in temperatures of 40oC. The optimum monthly temperature for cashew nut growing is 27oC. Cashew flowering is not affected by day length. Trees normally flower towards the end of the rainy season, when new shoots emerge, and a dry spell during flowering and fruit setting ensures a better harvest and high quality cashew nuts. Heavy rainfall, evenly distributed throughout the year, is not favorable for cashew trees, though they will still grow and sometimes set fruits. An ideal climate for cashew has a well-defined dry season of at least four months to produce the best yields. Cashew nut is widely regarded as a robust tree crop that can grow in any soil types, with little or no effect on productivity. While it is true that cashew has few soil requirements and can adapt itself to a wide range of soil conditions, its performance in terms of growth and yields is significantly improved by fertile soils of a suitable type. The best soils for cashew are deep and well-drained sandy loams without a hard pan, which facilitate the quick development of the tap root and the lateral roots system. Deep sands, sandy loams, gravelly soils and red laterite soils have been shown to be ideal for cashew in a number of African countries. Cashew also grows well on pure sandy soils but this may lead to mineral deficiencies that require special nutritional attention. Waterlogging and flooding often have a negative impact on cashew nut production. For this reason, heavy clay soils with poor drainage are not suitable for cashew cultivation. According to the FAO (1994), the optimum pH of soil for cashew growth is between 4.5 and 6.5. A soil pH below 3.8 or above 8.0 will negatively affect cashew production. Again, the cashew tree does not tolerate saline soils well and tends to grow poorly in valleys, floodplains and swampy areas that have poor drainage.

For many years, farmers have been growing the local cashew nut varieties and other accessions that were brought into the country from neighboring countries. However, many years of cashew research at the Industrial Research Institute of KALRO in Mtwapa led to the development and eventual release of four new cashew varieties, namely KKorosho 75, KKorosho100, KKorosho 81 and KKorosho 82. Among their many good attributes, include early maturity.

Cashew is grown for its fruits as well as nuts. Cashew trees are grown primarily for their kernels, which when roasted have a pleasant taste and flavour. The kernel is obtained by shelling the roasted nuts.  Cashew ranks amongst the important and valuable edible nuts in the world trade. The kernels are often one of the ingredients in various kinds of dishes. They are also used for confectionary purposes and in the preparation of many sweets. Cashew nut shell liquid (CNSL) is used in manufacturing products such as paints, plastics and brake linings. A wide array of different by-products (around 30) which can also be obtained from cashew apple include fresh apple, juice, canned apple, processed pulp, jam and jelly, dried apple prunes or raisins, sweet mass, syrup, candied fruit, chutney, alcoholic and non-alcoholic beverages (such as fermented juices, soft drinks, brandy, vinegar) and cashew apple meal for livestock.

The cashew nut shells produce oil which is used as medicine, preservative and water proofing agent. The oil is also used in the manufacture of insulating varnishes and acid proof cements, tiles and inks. The raw cashew apple is edible and is a valuable source of sugar, minerals and vitamins. Nutritive values of cashew apple and nut are very high. Cashew apple is a very good source of Vitamin C. It contains 12.3% carbohydrate and 10% phosphorus and calcium. Cashew nut (kernel) contain protein (21.2%) and fat 46.9%) and carbohydrate (22.3%). It also contains comparatively good amount of minerals, including iron and phosphorus. The wood and shells are used as fuel. The cashew value chain therefore offers a wide range of employment opportunities along the various nodes for women, youth, the vulnerable, and the marginalized.

Suitability Maps

Publications

Conference papers
Muniu, F.K. and Schnier, F. (2004) Cashew powdery mildew control in Coast Province. Proceedings of the Ninth Biennial KARI Scientific Conference ‘Agricultural Research for Improved Productivity and Livelihood’, Nairobi, 8–12 November 2004, pp. 67–70. 
F. K Muniu and F. N. Pole (2021). Status of Research on the Cashew Nut Value Chain in Kenya. Board paper.
Muniu F. K., Menza M. K., Mwashumbe S. K., Ondiko C. N., Danda K. M., Muriuki S. J. N., Mbuthia A. P., Ndubi J. M., Esilaba A. O., Ndungu J. N., Mwangi H., Wayua F. O, Nasirembe W. W., Wambua J. M., Otieno M., Ndambuki J., Kirigua V. O., and Wasilwa L. A. (2021). Cashew Technologies, Innovations and Management Practices (TIMPs) for Climate Smart Agriculture Project. 
Muniu F. K., Menza M. K., Mwashumbe S. K., Ondiko C. N., Danda K. M., Muriuki S. J. N., Mbuthia A. P., Ndubi J. M., Esilaba A. O., Ndungu J. N., Mwangi H., Wayua F. O, Nasirembe W. W., Wambua J. M., Otieno M., Ndambuki J., Kirigua V. O., and Wasilwa L. A. (2021). Training of Trainers' Manual for cashew. 
Mwashumbe S K1, Muniu F. K1,  D. Odhiambo1, C. Omondi2 and G. Keya3 and Saina N (2023). Morphological diversity and yield potential of cashew germplasm in Coastal Kenya. Presented during the 1st KALRO Conference in March 2023 at KALRO headquarters. 
Muniu F. K1, S. Mwashumbe1, D. Odhiambo1, T. Kosium2, M. Ojung’a2, G. Juma3, C. Omondi4 and G. Keya (2023). Newly released Kenyan cashew varieties. Presented during the 1st KALRO Conference in March 2023 at KALRO headquarters.

Technical manuals
Muniu F. K., Menza M. K., Pole F.N., Mwashumbe S. K. Wachenje D. W., Kiponda O., Chebet L. L, and Wasilwa L. A. AFA and KALRO, (2023). Cashewnut Growers’ Guide.
F.K. Muniu and S. Mwashumbe (2019). Cashew grafting training for National Irrigation Board staff in Bura. 
F.K. Muniu and S.K. Mwashumbe (2019). Cashew nursery establishment and top-working training for farmers and youth groups in coastal Kenya. Consultancy for services for FARM AFRICA. 
Francis K. Muniu, Stella Mwashumbe and Finyange Pole (2018). Development of contents of KALRO Cashewnut growing guide application uploaded onto Play store. 

Brochures
Muniu F.K., Mwinga w.s, Mwakangalu M. (20010. Cashew for cash.

Success Stories

• Release of 4 high yielding cashew nut varieties in 2023. The varieties were KKorosho 75, KKorosho 81, KKorosho 82 and KKorosho 100.
• Farmers in coastal Kenya are embracing the planting of new cashew varieties

Implementing Institutions

• KALRO
• MoALF
• County Governments (Kwale, Kilifi)
• NOCD
• KEPHIS
• KEBS
• Processors
• NGOs
• CBOs
• Farmers

Master Trainer

Name	Title	Specialization	Institution
Finyange N. Pole	Value Chain Lead (Principal Research Scientist)	Agronomy, Mechanization and Soil sciences	KALRO – ICRI Mtwapa
Francis K. Muniu	Senior Research Scientist	Agronomy (Varieties, Agronomy)	KALRO – ICRI Mtwapa
Stella Mwashumbe	Senior Research Scientist	Socio-economics (Propagation, Orchard rehabilitation)	KALRO-DRC Msabaha
Mwalimu Menza	Senior Research Scientist	Horticulture Breeding (Food safety, Safe use of pesticides, Climate smart agriculture)	KALRO – ICRI Mtwapa
Kadenge Lewa	Senior Research Scientist	Socio-economics (Policy, marketing, gender, business development	KALRO – ICRI Mtwapa
Alfred Mumba	Research Technologist	Laboratory Technologist (Pests and diseases -practicals)	KALRO – ICRI Mtwapa
Jackeline Kanyua	Hospitality Officer	Products development (Cashew value added products-Practicals)	KALRO – ICRI Mtwapa
Charity Gathambiri	Senior Research Scientist	Post-harvest specialist (Cashew value addition)	KALRO-HRI-Kandara
Cecilia Ngugi	Senior Research Scientist	Pathologist (Cashew nut pests and diseases)	KALRO-HRI-Kandara