:: About THE
CROP - CASHEW ::
occidentale L.) belong to the family Anacardiacea. It was originally introduced
into India by the Portuguese during the 16th century. The cashew kernels are used in
confectionery and dessert. The shells contain a high quality oil known as cashewnut shell
liquid (CNSL) which has got wide industrial uses. Cashew apple is eaten fresh or mixed in
fruit salads and a drink is prepared from the juice. Cashew can be distilled to produce
alcoholic drink (Fenny).
Cashew is essentially a tropical crop, grows best in the warm, moist and typically
tropical climate. The distribution of cashew is restricted to altitudes below 700 m where
the temperature does not fall below 200C for prolonged periods, although it may be found
growing at elevation up to 1200 m. It is best adopted to the coastal regions. The cashew
is hardy and drought resistant, but it is damaged by frost.
Cashew is grown in areas with rainfall ranging from 600 4500 mm per annum. Fruit
setting in cashew will be good if rains are not abundant during flowering and nuts mature
in a dry period.
Cashew is a sun loving tree and does not tolerate excessive shade. It can tolerate
temperature of more than 360C for a shorter period but the most favourable temperature
lies between 24 C to 28 C.
The climatic factors influence the cashew growth and production as follows:-
Dry spell during flowering and fruit setting ensures better harvest.
Cloudy weather during flowering enhances scorching of flowers due to
tea mosquito infestation.
Heavy rains during flowering and fruit set damages production.
High temperature (39-420C) during stage of fruit set development
causes fruit drop.
Cashew is an hardy crop. It can be grown on a wide range of soils except heavy clay, water
logged and saline soils. Well drained red, sandy and laterite soils are ideal for good
growth and yield of cashew.
Selection of suitable cashew varieties for the specific region and appropriate package of
practices determines the final yield. More than 30 varieties which are having exportable
grade of cashew kernels are released from different research institutes in India and
details are furnished separately.
Selection of planting material is most important in cashew cultivation. Cashew is
highly cross pollinated and vegetative propagation is mainly recommended on commercial
scale to produce true to type planting materials. Softwood grafting is the only method
which is commercially feasible and practically highly successful in cashew.
The normal recommended spacing is 7.5 x 7.5 m to 8 x 8 m and spacing may be reduced up to
4m x 4m depends on type of soil and managerial capacity.
The high density planting consisting of up to 625 plants/ha can also
be adopted for better utilization of space during early years. Initial planting can be
done at a spacing of 4mts x 4mts or 5mts x 5mts or 6mts x 4mts and maintained up to a
period of 7 to 9 years with proper pruning and training. Later the excess plants can be
thinned out to provide a final spacing of 8mts x 8mts or 10mts x 10mts or 6mts x 8mts.
Method and season of planting
The square system of planting can be followed. The ideal time for planting is usually
during monsoon season when the moisture is air surcharged (June-August) both in the west
coast and east coast. If irrigation facilities are available, planting can be done
throughout the year except winter months.
Normally cashew grafts are planted in the pits of 60 cm. cube. It is
preferable to dig the pits at least 15-20 days before planting and expose to sunlight so
that termites and ants, if any, which damage the roots of the grafts will migrate
elsewhere. The pits should be completely filled with a mixture of top soil and organic
manure to ¾ of the pit capacity. The grafts are planted after carefully removing the
polythene bag. Care should be taken to see that the graft joint remains at least 5 cm
above the ground level at the time of planting. The polythene tape around the graft union
need to be removed carefully. Staking should be done immediately after planting to protect
the grafts from wind damage. Mulch the basins of plants with organic waste materials
during early years.
Application of manures and fertilizers
Manures and fertilizers promote growth of the plants and advance the onset of flowering in
young trees. Application of 10-15 kg of farm yard manure or compost per plant is
beneficial. The current fertilizer recommendations for cashew is 500 g N (1.1 kg urea),
125 g P205 (625 g rock phosphate) and 125 g K2O (208 g Muriate of potash) per plant per
year. The ideal period for fertilizer application is immediately after the cessation of
heavy rains and with available soil moisture. During the 1st, 2nd and 3rd year of planting
1/3rd, 2/3rd and full doze of fertilizers should be applied and 3rd year onwards full
quantity is to be applied.
Clearing the area by manually within 2mtr radius of the trunk and slashing the remainder
is essential until the trees shade out most of the trees. Weeding can be done by
chemically also. Glyphosate (post emergent) application at 6 to 7 ml per litre of water
(0.8 kg a.i./ha) during June July also effectively controls weeds.
Mulching the tree basins will help in conservation of soil moisture and prevents soil
erosion. Mulching with organic matter or residues inhibits weed growth and reduces surface
evaporation during summer and also regulates the soil temperature.
Under sloppy areas, soil and water conservation practices can be
done by making trenches of 30 cm width, 60 cm depth. And convenient length may be taken in
between rows along the contour. This will mot only conserve soil and moisture but will
also enable to enhance the growth of cashew.
Training and pruning
Training and pruning is the important horticulture practice to be employed to make better
frame work of cashew plant. It helps to control growth and make easy for cultural
practices. The sprouts arising from the root stock portion of the cashew graft should be
removed frequently during the first year of planting. As an orchard management technique
to improve the sanitation, removal of water shoots, lower branches, crisscross branches
and dry branches are found to be beneficial to enhance flowering and the yield.
In India cashew is grown mainly under rain fed condition. However protective irrigation
especially summer months during January-march at fortnightly intervals @ 200 liters/plant
improves fruit set, fruit retention, thereby increasing nut yield.
Intercropping received little attention in the cashew. However, depending on soil and
climatic conditions and local situations annual vegetables like tapioca, pulses, turmeric,
ginger etc, can be grown as inter crops. When once the plants become sufficiently big
pepper can be taken as mixed crop.
Tea mosquito, stem borer, thrips, leaf minor and leaf blossom webber are important pests
of cashew. Of these, tea mosquito and stem borer causes economical damage in cashew.
Tea mosquito: Tea mosquito bug (Helopeltis antonii s.) can
cause yield reduction to the tune of 30-40 per cent damaging tender shoots, inflorescence
and immature nuts at various stages of development. It attacks the tree in all the seasons
during flushing, flowering and fruit setting period but the peak period of infestation is
from October to March. To control the pest, spray schedule involving three sprays
synchronizing new flushing (October-November), flowering (November-December) and fruit
setting (January February) may be given with the following chemicals:-
Quinalphos (25% EC) - 0.05%
Carbaryl (50% WP) - 0.01%
Phosphamidon (85% WSC) - 0.03%
The number of sprays should be limited to three and the same
insecticide should be used for the subsequent sprays.
Stem and root borer - Stem and root borer (Placaederus
ferrugineus L.) is also a dangerous pest and kill the entire plant. It is mostly seen in
neglected gardens. The larvae of a beetle tunnel into the tree trunk and eats the bark all
around the trunk. Manual removing of grubs and pasting the damaged portion with mixture of
Carbaryl 50 gm (50%) and copper Oxychloride (25 gm) in one liter of water give effective
Harvesting and yield
The flower panicles emerging from the graft during 1st and 2nd year should be removed in
order to allow the plant to put good vegetative growth and better framework. Economic
bearing in cashew commences after 3rd year of planting. The ripened will fall down and
nuts from fallen fruits have to be collected. Nuts can be dried in sun for 2 to 3 days on
cement floor and can be stored in gunny bags. The yield starting from 1 kg in 3rd-4th
year, yield goes on increasing as the canopy develops and one can expect more that 10 kgs.
of nuts in 8 to 10 years old plant depending on management.
Marketing of raw cashewnuts
Marketing of raw cashewnut in India has not yet been organized in
systematic manner except in Goa where co-operative marketing society is procuring raw nuts
to the little desired extent. A major portion of the produce is brought by itinerant
merchants and the agents of the processing units. A number of wholesale merchants and the
processing factories open their collecting centres in important cashew producing areas
during the harvesting period. The petty dealers who buy the nuts from the growers also
dispose the nuts in these collecting centres. Cashewnut are brought for sale to the
assembling markets largely by the itinerant merchants. In certain areas, the most
resourceful processors contact the producers thus avoiding the commission agents role and
enjoy good bargaining power by providing credit facilities to the producers.
As there are a number of intermediaries operating the field between
the primary producer and the processing unit. The different costs and margins in the total
spread between the producer and the processing unit are quite significant and the
producers share in the price paid by the processing units generally low.