Cashew Cultivation
Cashew (Anacardium occidentale) is an evergreentropical and frost sensitive tree crop that forms large
canopy and can grow to 12 metres high. It grows well in
fertile sandy loam soil, requires temperature between 25 -
30 degree celsius and precipitation between 1000 and
2000mm. It is a native of Brazil and was introduced in
Nigeria by Portuguese in the 16th century. The tree is
mostly valued for the nuts which are mainly harvested
once in a year.
Indians and Indonesian importers are the major buyers
of the nut in Nigeria. They mostly buy from places where
quality cashew nuts are produced in abundant quantities.
Reports and observations from cashew nut production
and marketing have shown that the bulk of quality
cashew nuts comes from Ogbomoso, Oyo State. The
town has suitable soil and weather for cashew nut
production.
Cashew varieties
There are three main varieties which are Brazilian
cashew, Chinese cashew and Indian cashew. Brazilian
cashew is mostly grown in Nigeria.
Land preparation and planting
After clearing of the vegetation, the land must be
ploughed and harrowed. The nuts can be sowed 3 -4 per
hole or raised in nursery and transplanted in the field.
After the establishment the plant are thinned to one
healthy and vigorous plant per stand.
Plant spacing
Two spacing methods can be adopted and these are 9m
X 9m and 4.5m X 4.5m. The improved varieties start to
produce fruits eighteen months after planting. The yield
can't be much during the first few years but after 5 years
there will be increase in the yields. Cashew can be
intercropped with arable crops such as soybean,
cowpea, groundnut, melons and vegetables for some
years. It is not advisable to to intercrop cashew with
corns because the crops can grow taller than the
seedlings and cast shadows on them. The crops can
also cause significant removal of soil nutrients.
Expected yields can be determined as follows:
At 18 months after planting 1kg per tree is expected, and
with the spacing of 4.5m X 4.5m, 132 plant stands will
produce average of 132kg per acre. Between 3 and 5
years it will produce average of 15kg per tree and 1980
kg per acre. Between 5 and 10 years it will produce
average of 35kg per tree and 4620kg per acre. Above ten
years a tree will produce average of 80 kg per plant. The
plant population should be reduced to 9m X 9m at the
end of 5 year to allow the trees to form big crowns.
Weeding
Manual and chemical weeding can be practiced. Manual
weeding can be done at the seedling stage but after full
establishment, herbicides can be used in the plantation.
Contact herbicide is recommended, but the spray must
not touch the leaves.
Flowering
Flowering and fruiting is affected by the weather
condition. It takes two months from flowering to
ripening of the fruit, and flowering can continue for
three months.
Harvesting
The apple must be harvested and processed immediately
because it is highly perishable and gets spoilt within few
hours. It can be eaten fresh or processed into juice. The
nuts must be well dried in the sun before they are
bagged and stored. Well dried nuts can be stored more
than a year before they are shelled or sold.
The apple is very rich in nutrients, 3 times greater than
orange in vitamin C. Syrup, wine and gin can also be
produced from the apple. The nut kernel contains 21%
vegetable protein and is as rich as milk, egg and meat in
proteins, vitamins and minerals.
Shell oil or fluid is a by product that contains
combination of anacardic acid and cardol. It is used in
the manufacturing of materials that are resistant to heat,
friction and caustic products. It is used in clutch plates,
special isolators, varnish and plastic materials.
The bark of cashew tree is rich in tannin being used in
leather tannin. Other parts such as leaves, fruits, wood,
gum, bark and juice are used for preparation of local
medicines.
Measuring quality of Cashew nut
The quality of cashew nut is measured by Kernel Outturn
Ratio (KOR) which is the amount of usable kernels after
shelling of the nuts. It is measured as the weight of the
kernels in Ibs per bag of cashew nuts (80kg or 176 Ibs).
A KOR of 48 means there are 48 Ibs (21.8 kg) of usable
cashew nut kernels in a bag of 176 Ibs (80kg). KOR
ranges between 20 - 24%.
Cashew nut is an export commodity and highly
demanded for in the USA, Japan, Australia, Canada and
some European and Middle East countries.