Cashew (Anacardium occidentale) production

Land Preparation

Cashew which is a native of Brazil was introduced during the latter half of the 16th Century for the purpose of afforestation and soil conservation in India. Cashew cultivation is taken up in small and marginal holdings and as more than 70% of the cashew area is under this category, cashew plays an important role in the development of small and marginal farmers.

Land with good drainage and devoid of sub-surface hard rock or hard pan, is successful for cultivation of cashew. In case of agricultural lands, it should be ploughed and leveled. For forest lands, after clearing and burning of debris, the land should be terraced or bunds constructed in sloppy land. Pits of 1 m3 are to be dug and allowed to wither.

Soil

There is a general concept that “cashew is very modest in its soil requirements and can adapt itself to varying soil conditions without impairing productivity”. However, cashew grows well on good soils than on degraded soils. The best soils for cashew are deep, friable well drained sandy loams without a hard pan. Cashew can also grow on pure sandy soils even though mineral deficiencies are more likely to occur.

Climate

Cashew is a tropical plant therefore areas where temperatures ranges from 20 to 30 degree Celsius with an annual precipitation of 1000 – 2000 mm are ideal for its growth and development. A climate with a well defined dry season of at least four months to produce the best yields is required. Coincidence of excessive rainfall and high relative humidity with flowering may result in flower/fruit drop and heavy incidence of fungal disease though the trees may grow and some times set fruit. The young cashew plants are sensitive to frost.

Varieties

Several varieties have been released by the different co-ordinating centres of ICAR. Also, research programmes in the field of crop improvement have identified best materials with yield potential ranging between 20-25 kg per tree.  Bud wood bank with the released varieties of respective centres, for further multiplication and distribution have been established by all Agricultural Universities and Research Centres. Some important varieties are:

BPP-1: High percentage of perfect flower, 13.2%, fruit set high, yield 17 kg (25-year-old plant) per plant, shelling, 27.5% nuts of 5g average weight.

BPP-2: Yield 19 kg/tree (25 years), shelling 26%, nuts 4g average.

BPP-3,4,5: are also other good varieties.

Vengurla-1: Average yield 23 kg/plant at 28 year’s age, nut weight 6g, shelling 31%.

Vengurla-2: Yield 24 kg/plant at 20 year’s age, nut weight 4 g, shelling 32%.

Vengurla-3: Nut weight 9 g.

Vengurla-4,5, VRI-1,2, Ullal-1,2, Anakkayam-1, BLA 39-4, K-22-1, NDR 2-1.

K-22-1 and NDR 2-1 are good export varieties.

Planting material

Cashew is a cross pollinated crop and Cashew exhibits wide variations in respect of nut, apple and yield of seedling progenies. Therefore, vegetative propagation has been advocated to mitigate this problem. Other methods of propagation such as budding and grafting have been found successful. Number of Adequate thrust has been given to produce enough planting materials through these standardised techniques of propagation, by the ICAR (through the National Research Centre for Cashew, its sub-stations, Agricultural Universities and State Departments of Horticulture/Agriculture), to meet the growing demand.

Layout and Planting

The preferably layout for planting cashew trees is to plant by the equilateral triangular system, especially on the slopes, as this accommodates 15% more plants without affecting the growth and development of the trees. In undulating areas they are preferably planted along the contours, with cradle pits or trenches provided at requisite spacing in a staggered manner to arrest soil erosion and help moisture conservation. The general plant spacing for cashew is 7 to 9 meters usually by the square system. It is desirable to dig the pits well in advance and allow sufficient time for withering. Burning of the debris and forest wastes inside the pits before planting is advantageous. Also, it is essential to provide stakes and temporary shade with the locally available materials wherever necessary (especially in the South West aspects in case of forest plantation) to reduce the mortality rate and achieve quicker establishment.

The grafted plants obtained from the superior mother plant are usually planted after filling the pits (1 m3 size) with top soil and Farm Yard Manure at the onset of monsoon.  If the monsoon rains are inadequate, one or two pot waterings can be done during the initial stages to ensure establishment. Mulching with black polythene is beneficial to increase the growth and yield of cashew.

Manuring

The nutritional requirements of cashew are shown on the table below:

Nutrient	Grams per tree per year
	1 Year	2 Years	3 Years and after
N	170	340	500
P2O5	45	85	125
K2O	45	85	125

 

Fertilizer application should be done in a circular trench of 25 cm broad and 15 cm depth at 1.5m from the tree trunk for areas with sandy and laterite soils, soils of sloppy land and in heavy rainfall zones. Also in red loamy soils in low rainfall zones, circular band application in an area of 1.5 m width between 1.5m and 3.0m from the trunk, and incorporation in to the soil should be practised. The fertilizer should be applied in two split doses in pre and post-monsoon period. However, if single application is to be done, it should be in post-monsoon season where adequate soil moisture is available.

Weeding

Slashing weeds with the advancement of dry season is hardly beneficial. Like wise deep digging during or just at the end of monsoon is detrimental, as it may lead to soil erosion especially in sloppy lands or formation of hard pan after the monsoon is over. Therefore timings of weeding are very important to minimise cost. Weeding with a light digging should preferably be done before the end of rainy reason. Hoeing, cutting the weeds off underground is more effective than slashing. Chemical weeding may be considered as an alternative, where labour is insufficient.

Inter-cropping

Inter crops which can replace weeds and as such would not compete for light, moisture, nutrients and can be harvested very early in the dry season or at the end of rainy season may be taken up. Leguminous crops such as groundnuts and beans are very suitable for inter cropping.   Inter cropping is usually recommended owing to the long pre-bearing period and low income in the early period of bearing and fluctuations in the yield and price from year to year. It is not advisable to inter crop with tall growing crops like maize, sorghum and millet between young cashew, as they provide too much shade.

Pests and Diseases

30 species of insects have been observed to infest on cashew. Out of these, tea mosquito, flower thrips and stem and root borer and fruit and nut borer are the major pests, which are reported to cause around 30% loss to the yield.

Tea Mosquito (Helopeltis spp.)

During the beginning of the rainy season when the cashew tree is full of new fllush, tea mosquito population builds up. The nymphs and the adults suck sap on the tender leaves, shoots and inflorescence and even young nuts and apples. Severe attack on the young shoots cause dieback. Attacked inflorescence usually can be recognised from a distance by their scorched appearance.  Also, saliva of the insect can be very toxic as it could cause blistering at the site of infestation.

• control

Tea mosquito can be controlled by spraying carboryl 0.1. % or phosalone 0.07% or endosulfan 0.05% or dimethoate 0.05%. Spraying should be done thrice, first at the time of flushing, second at early flowering and third given at the time of fruit set.

Thrips

These thrips are more active during the dry season. Both nymphs and adults suck and scrape at the underside of the leaves, mainly along main veins, causing yellowish patches, latter turning grey, giving the leaves a silvery appearance.

• control

0.05% monocrotophos or 0.1% carbaryl are very effective for controlling thrips.

Stem and Root Borers

The young white grubs bore into the fresh tissues of the bark of the trunk and roots and feed on the subsequent subepidermal tissues and make tunnels in irregular directions. Due to severe damage to the vascular tissue the sap flow is arrested and the stem is weakened. The characteristics symptoms of damage include the presence of small holes, in the collar region, gummosis, yellowing and shedding of the leaves and drying of the twigs.

• control

Complete control of this pest once the plant is infested is very difficult. However, prophylactic measures for its control can be adopted with 0.1% BHC swabbing twice a year, once in April-May and the second application during November.

 

Fruit and nut Borers

This pest causes deformity and loss of kernel weight as the young caterpillar bores through the apple and nut.

• control

Spraying of endosulfan at 0.07% or monocrotophos 0.05% concentration at flowering and fruit setting is recommended.

Diseases

Except for the powdery mildew caused by a fungus, which affects the young twigs and inflorescences and make it wither, cashew crop does not have any serious disease problem.  This fungal disease appears when the weather becomes cloudy and can be controlled by dusting with 2% sulphur W.P.

Harvesting and Yield

Fruit are usually harvested before it falls naturally if the apples are to be used for making jam, juice, syrup, fenni, etc. However, if harvesting for the nuts alone, fruits can be allowed to fall off naturally to the ground after manuring, then the nuts are reaped off.. ormally harvesting consists of reaping the nuts that have dropped to the ground after maturing. However, , the Plantations of unknown origin or seeding progenies with conventional methods of cultivation yield less than one kg of raw nuts per tree. With the use of the best planting material coupled with a package of improved agronomic practices, a yield of 8-10 kg per tree could be achieved.

Processing

The processing of cashew involves the following steps:

– Preliminary cleaning: manual picking of large objects and by sieving.

– Roasting: cleaned cashew nut is roasted in open pan or earthen ware or rotary cylinder or hot oil bath.

– Shelling and separation: after roasting, the shells are removed and the nuts extracted manually. In manual shelling, recovery of whole kernels is more compared to the mechanical shelling.

– Drying: the kernels are dried in hot air chambers.

– Peeling: drying the kernels facilitates peeling of the outer coating.

To prevent breakage, the kernels are to be handled very carefully, as they are brittle at this stage. The shelling percentage of cashew varies from 20-25.

 

Grading

This is done for export purposes based on “counts” or number of kernels per lb. Sound kernels are named as “wholes” and broken ones as “splits”. The wholes are again classified as whole white kernels, whole scorched kernels, whole dessert kernels (a) and whole dessert kernels (b). The splits are also further graded into white pieces, scorched pieces, dessert pieces (a) and dessert pieces (b) based on certain physical characters. The wholes are packed in several grades viz., 210, 2401, 280, 320, 400, 459 and 500; the popular grade is 320. The specifications for graded kernels are that they should be fully developed, ivory white in colour and should be free from insect damage and black and brown spots. Packing is done in time by Vita pack method (exhausting the air inside the packing tin, pumping in carbon dioxide and sealing).

 

Marketing

Marketing of cashew is not a problem in view of the fact that our raw material production is considerably low when compared to the processing capacity of our existing factories.