Cashew nuts

Scientific Clarification

The following are the crop details for Cashew Nuts

  • Scientific name: Anacardium occidentale
  • Local names: Mkorosho / mkanju (Swahili)
  • Order: Sapindales
  • Family: Anacardiaceae
  • Genus: Anacardium

General Information

Cashew is an evergreen tree with deep tap roots, grown for its edible fruits (nuts). The cashew tree has a branching main trunk and characteristic domed crown. The thin foliage of the tree is limited to the ends of the branches and is made up of oval-oblong leathery, shiny dark green leaves. 

The leaves are smooth with pronounced veins and midrib and possess petioles that are swollen at their base. The tree produces numerous pinkish-white flowers on drooping panicles and a kidney-shaped true fruit (nut) which is approximately 3 cm (1.2 in) long with a grey-brown shell and develops from a fleshy accessory fruit, sometimes referred to as the 'cashew apple'. The cashew apple is pear-shaped and red to yellow. 

Cashew trees can reach a height of 12 m (39.4 ft) and have an economic lifespan of 25 years after which time they are replaced in commercial plantations. 

Cashew originates from Brazil. The Portuguese introduced cashew to Mozambique in the 16th century where it flourished, forming extensive forests; eventually, it also became dispersed in East Africa along the coastal plains of Kenya and Tanzania.

Cashew Varieties in Kenya

Recommended varieties of cashew nuts by KALRO are A75/83, A100, A81, and A82.

Climate Conditions, Soil, and Water Management

Cashew trees are usually grown at altitudes of between 0-500 m above sea level (asl) but can grow up to 1000 m asl. They can be very drought resistant provided their roots penetrate deeply into the soil and draw water from the subsoil. For mature trees 500 mm of rainfall per year is adequate, but seedlings should be watered until properly established. If rainfall is below 900 mm per year plant at the widest spacing indicated. Cashew nut trees tolerate a wide range of soils provided they are deep and well-drained. They can grow quite well on infertile soils but do not do well on coral outcrops at the coast.


The kernels or nuts have a high nutritional as well as commercial value and are used for human consumption either raw or roasted. The cashew nut apple is rich in Vitamin C (about 5 times higher than the orange) and is used for the production of juice, wines, spirits, jam, pickles, and chutneys. The liquid of the shell is used for brake linings, heatproof and waterproof paints, and protective varnishes. Cashew nut wood is of poor quality but can be used as firewood if mixed with other types of wood.

Planting Procedure

Cashew nuts should be planted at the beginning of the rainy season. In the Coastal lowlands, the best time for planting is between April to June.

Cashew nuts are usually propagated through seed or grafted seedlings. In propagation by direct seeding 3 seeds are planted in the planting hole and two months after germination the weak seedlings are uprooted leaving the strong ones to grow.

The holes should be 60 cm by 60cm so that they can be able to collect water during the rainy season which will be used during the dry season.

Cashew trees are generally planted with a spacing of 7.5 m X 7.5 m (175 plants/ ha) or 8 m X 8 m (156 plants/ ha) is recommended. High-density planting of cashew at a closer spacing of 4 m X 4 m (625 plants/ ha) in the beginning and thinning out in stages to maintain a final spacing of 8 m X 8 m in the tenth year is also recommended.

Proper seed selection from healthy, high-yielding trees is important, and it can be done by sorting out seeds by the water density method:

  • Place the seeds in a bucket of seawater (100 g salt per 5 liters of water) and select the seeds that sink for planting. Those that float have poor germination and growth potential.
  • Sundry seeds for planting for several weeks to prevent mold and rotting.
  • Do not plant seeds that are more than one year old.

Intercropping can be done before the canopies close. Most annual crops can be used apart from cotton and sweet potatoes, which are host plants for Helopeltis bugs, major pests of cashew. Do not interplant young trees with pasture because of the high competition for water during the dry season.

Planting using grafted seedlings

Propagation through grafting starts by raising rootstock propagated from local cashew nut varieties. The first step is a visual selection of seeds to remove diseased or deformed seeds. The selected seeds are taken through a flotation test in water. Seeds that sink are planted in pre-germination beds.

The pre-germinated seeds are transplanted into potting bags when the radicals (tap root) are 2.5 –3cm after 7-10 days. The recommended soil media for cashew nut seedlings is in the ratio of 2:1:150 where: 2 is two buckets of soil, 1 is one bucket of well-decomposed farmyard manure, and 150gms of DAP. The seedlings are transplanted in potting bags (6" x 9"). This composition can sustain the plant for an average of three months after transplanting the pre-germinated seeds in them.

Seedlings are ready for grafting when they attain more than two functional leaves and the cotyledons are still attached to the young stem. Grafting is done 3-4 weeks after transplanting into potting bags. 

Scions for grafting are harvested from select mother plants. The following procedure for 

grafting is recommended:

a. Cut and remove the actively growing part of the rootstock, leaving two functional leaves. 

b. Vertically cut down the stock between the two leaves to a depth of 2.5 – 3.0cm.

c. Make a wedge cut of the scion of a similar length of 2.5-3.0 cm and sharpen it.

d. Insert the scion into the rootstock and tie them together.

e. Cover the scion and the rootstock by wrapping them with grafting tape.

f. Wait for 2-3 weeks and unwrap the scion.


No fertilizer is required, but well-rotted manure at planting is beneficial. The area around the tree should be 1 ½ times the size of the canopy and should be kept clean of weeds for the first 2 years to avoid competition. 

If planted on a slope the tree should have a U-shaped mound of soil below it to collect rainwater for improved growth. Seeds germinate within 2-4 weeks. Thin after 3-4 months leaving only the strongest plant at each site. 

Mulching with black polythene is beneficial to increase the growth and yield of cashew. However, locally available materials like green or dry grass or weeds can be utilized for mulching the basins. Small pebbles or stones can also be used for mulching the basin.

Plastic or stone mulch does not improve soil health but ensures better moisture retention in the soil and also prevents the attack of soil-borne insects and pests.

The topsoil and sub-soil are kept separately and allowed to wither under the sun. It helps in the migration of termites and ants(this is in the planting process).

Weeding with light digging should preferably be done before the end of the rainy season. Hoeing, cutting the weeds off underground is more effective than slashing.

Cashew plants start bearing after three years of planting and reach full bearing during the tenth year and continue giving remunerative yields for another 20 years(so they can yield up to 45 years after being planted).

Protect seedlings from monkeys, rodents, and bucks by placing wire cages or thorns around the seedlings. Support plants with a stick and trim off side shoots up to 60-90 cm from ground level. When trees are mature, prune dead wood or any borer-damaged or intergrowing branches to give the canopy air and light. 

Harvesting and Postharvest Handling

Cashew nuts planted using seeds begin bearing 3 to 4 years after transplanting the seedlings. The nuts should be harvested as soon as possible, especially under wet conditions, and should be dried before storage.

Grafted seedlings begin bearing within 2 years of transplanting. Depending on the age and maturity of the plant, a tree yields between 10 to 100 kilograms of unshelled nuts per year. One hectare can thus produce between 2,000 to 5,000 kilograms of unshelled nuts per year. Although trees are produced for 40 to 50 years, commercial harvesting is for 35 years. 

The cashew nuts do not mature at the same time. The duration of harvest extends from 45-75 days and the nuts should be collected daily during this period. November to May is the harvesting period, with the peak harvest period from November to January. The nuts are collected at weekly intervals from the farm during the harvesting season. During that period the land should be clean to facilitate the collection of cashew. To get good quality nuts, clear the area beneath the tree, collect fallen fruits, detach the nut from the apple, and dry the nuts under the sun for about 2 hours.

The nuts can be graded into Fair Average Quality (FAQ) and Under Grade (UG). FAQ are well-matured nuts and they should be full and well-dried (12% moisture content). The color should be grey or pale brown. They should neither be wrinkled nor spotted.

UG are well-dried and mature nuts. They can be spotted but not wrinkled.


CABI Crop Protection Compendium. (2014). Anacardium occidentale datasheet. Available at: [Accessed 10 November 14]. Paid subscription required. Duke, J. A. (1983). Anacardium occidentale L. Handbook of Energy Crops. unpublished. Available at: [Accessed 10 November 14]. . Hammed, L. A., Anikwe, J. C. & Adedeji, A. R. (2008). Cashew nuts and production development in Nigeria. American-Eurasian Journal of Scientific Research: 3 (1): 54-61. Available at: [Accessed 10 November 14]. Free to access.

Common Pests and Diseases


Category : Bacterial

Angular leaf spot Septoria anacardii

Angular cream colored lesions with dark-brown margins on leaves of seedlings; angular black lesions with chlorotic halos on mature trees; defoliated seedlings
Some dwarf types of cashew are resistant to this disease; disease is widespread in cashew growing regions of Brazil
Currently no control measures are used

Category : Fungal

Anthracnose Colletotrichum gloeosporoides

Water-soaked lesions on leaves, twigs, flowers or young apples which develop into orange-brown or red lesions;
Disease emergence favored by rainfall and high humidity
A protective coating of copper-based fungicide on susceptible parts of plant can prevent the disease; fungicide should be applied when buds begin to expand through to fruit set but are not required during dry periods

Black mould Pilgeriella anacardii

Chlorotic spots on upper surface of leaves which spread to lower surface as infection progresses; dark-brown to black fungal patches on leaves; leaves shrivelling and dropping from plant
Damage most severe on dwarf cashew varieties


Category : Insects

Cashew weevil Mecicorynus loripes

Brown-black gummy frass (insect excrement) on trunk and branches; girdling of branches; plants dying
Adults large and gray-brown with knobbly appearance; larvae legless grubs which are white with a brown head
Remove bark from infested areas and destroy any larvae or pupae found, this process should be repeated every month for up to six months; severely infested trees should be removed and destroyed; remove all adult weevils from tree prior to destruction and also remove bark and kill all larvae and pupae

Coconut bug Pseudotheraptus wayi

Necrotic lesions on fruit which develop into hard lumps; pockmarks of fruit; spotting on kernels
Adults are red-brown in color; nymphs are red-brown to green in color
Conserve natural enemies by avoiding unnecessary applications of insecticides

Helopeltis bugs Helopeltis schoutedeni
Helopeltis anacardii

Deformed leaves with angular lesions along veins; leaves may drop from plant; elongated green lesions on young shoots which may exude gummy substance; dieback of shoots
Helopeltis bugs are slender with long legs and antennae; antennae twice as long as body; females are red; males brown; nymphs are yellowish in color
Monitor crop regularly for signs of damage; conserve populations of natural enemies, weaver ants can reduce populations; avoid interplanting cashew with other crops which are hosts for helopeltis bugs such as tea and cotton
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