The tree

The cashew-nut tree is a fast grower and an evergreen tropical tree. It grows to a height of 10-12 meters. Blossoming takes place between November and January. Seedling trees flower in the third year after planting. The fruit ripens fully within 2 months.

The fruit (nut)

The nut is attached to the lower portion of the cashew apple which is conically shaped. The cashew nut (seed) hangs at the bottom of the apple, and is c-shaped.

The cashew seed has within the outside shell the edible kernel or nut. In its raw form the cashew kernel is soft, white and meaty. When roasted it changes colour and taste. Salted, it appeals to the palate as the most delicious nut.

Cashew apples and cashew nuts are excellent sources of nutrition. The cashew apple contains five times more vitamin C than an orange and contains more calcium, iron and vitamin B1 than other fruit such as citrus, avocados and bananas.

Climatic requirements

Cashew trees are genuinely tropical and very frost sensitive.
Although the cashew can withstand high temperatures, a monthly mean of 25 °C is regarded as optimal.
Yearly rainfall of 1 000 mm is sufficient for production but 1 500 to 2 000 mm can be regarded as optimal.
The cashew tree has a well-developed root system and can tolerate drought conditions. 
During harvesting, while nuts are on the ground, rain and overcast weather causes the nuts to rot or start germinating.
Nuts germinate within 8-12 days when lying on wet soil.
Planting

Fresh seeds that sink in water in 12 hours are planted in an upright position in a planting bag containing a loose, sterilised soil mixture included compost. Three to four seeds can be planted directly in the planting hole. The weakest ones are thinned out later and the strongest left to develop further. The plant bags should be 350 to 400 mm deep, as the tap-root grows very fast and bends around as soon as it touches the bottom or You can plant cashew seeds on direct planting area without potting.

Planting distance

Planting distances of 8 x 5 m is recommended. The trees grow vigorously in the first 3 years and as soon as the crowns touch each other alternate trees should be removed until the permanent planting distance of 10 to 12 m is reached. Branches hanging on the ground should be removed because they interfere with harvesting. In other parts of the world cashew trees bear well, in spite of the little attention devoted to the orchards.

Fertilisation

The application of nitrogen and phosphate are important. Approximately 75 g year age of the tree is applied annually with a maximum of 750 g. Cashew trees are subject to zinc deficiency that can be treated with 200 g zinc oxide/100 l water applied as a leaf spray.This is an additional treatment & not essential.

Flowering to harvest time

Flowering is affected by weather conditions and also varies from tree to tree, but continues for a period of 3 months. High temperatures lead to earlier flowering. Both male and bisexual flowers are borne on one cluster. The flowers are very susceptible to mildew and control thereof on the leaves and flowers is a prerequisite for good production.

Pollination is mostly by insects. After pollination it takes 6 to 8 weeks for the fruit to develop. The nut develops first while the apple develops and enlarges only 2 weeks before fruit fall. Nuts should be harvested as soon as possible, especially under wet conditions and should be dried before storage.