All about cashew

1. Cashew nut

2. CONTENT
 INTRODUCTION
 CHARACTERSTICS
 BOTANY
 VARITIES
 SOIL
 CLIMATE
 PROPOGATION
 PLANTING
 INTERCROPPING
 COVERCROPPING
TRAINING AND PRUNING
 WEED MANAGEMENT
 MANURE AND FERTLIZERS
 TOP WORKING
 DISEASES
 PESTS
 HARVESTING
 YIELD
 GRADING
 POST HARVEST ACTIVITIES

3.  Scientific name – Anacardium occidentale
 Common name – caju, acaju
 Family - Anacardeaceae
 Chromosome No. - 42
 Origin - Brazil
 Distribution - Nigeria ,
Tanzania
South America,
India,
Malaysia

4. Introduction
 cashew, (Anacardium occidentale), evergreen shrub or tree of the sumac
family (Anacardiaceae), cultivated for its characteristically curved edible
seeds, which are commonly called cashew “nuts” though they are not true
nuts. The domesticated cashew tree is native to the New World but
commercially cultivated mainly in Brazil and India. The seeds, rich
in oil and distinctively flavoured, are commonly used in South and
Southeast Asian cuisine and are a characteristic ingredient of numerous
chicken and vegetarian dishes of southern India. In Western countries they
are eaten mainly as a premium-quality protein rich snack food.


5.  The cashew is native to northeastern Brazil. Portuguese missionaries
took it to East Africa and India during the late 16th century, where it
became abundant at low altitudes near the seacoast. The tree produces
wood that is useful in local economies for such practical items as
shipping crates, boats, and charcoal as well as for a gum that is similar
to gum Arabic. The resin within the shells of the fruit is used as
an insecticide and in the production of plastics, it also is important in
traditional medicines. The cashew apple is used locally in beverages,
jams, and jellies, though most cultivation is directed toward
production of the valuable seed crop. Parts of the cashew must be
handled with care by susceptible individuals because it is related
to poison and poison sumac and can cause an allergic reaction in
some people.

6. Plant characters
 The plant may grow to 12 meters (40 feet) in height where the soil is fertile and
the humidity high.
 The leathery leaves are spirally arranged and elliptical in shape.
 The curved fruit, which is not a true nut, is shaped like a large thick bean and
can reach more than 2.5 cm (1 inch) long.
 It appears as though one of its ends has been forcibly sunk into a pear-shaped
swollen stem (hypocarp), called the cashew apple.
 The cashew apple, which is an accessory fruit (e.g., not a true fruit), is about
three times as large as the true fruit and is reddish or yellow.
 The true fruit has two walls, or shells. The outer shell is smooth, thin, and
somewhat elastic and is olive green until maturity, when it becomes pale brown.
The inner shell is harder and must be cracked like the shells of nuts to obtain the
edible seed inside.
 A brown oily resin is produced between the two shells and can blister human
skin.


7. Botany
 The cashew tree is a low spreading, evergreen tree with a very prominent tap root.
The leaves are alternative, simple, glabrous, obovate, round and pinnately veined.
The inflorescence is an indeterminate panicle of polygamomonoecious type i.e.
flowers are either bisexual or staminate but both occur intermixed in the same
inflorescence. On the same tree, the perfect flowers are larger in size than the
staminate. Pollination is carried out by flies, bees and ants as well as by wind. The
fleshy peduncle, the ‘cashew apple’, is juicy and sweet when ripe. The apple varies
in size, colour, juice content and taste. It is rich source of vitamin c and sugar. The
cashew fruit is a kidney shaped drupaceous nut, greenish grey in colour. The nuts
vary in size, shape, weight (3-20g) and shelling % (15 –30%)

9. Habitat and growth

10. Varieties
 Tamil Nadu Varieties: vridhachalam 1,vridhachalam 2 ,vridhacalam 3, VRI 4,VRI
(CW) H1
 Kerala Varieties : akshay (H-7-6), Amrutha(H1597) ,Anagha (H-8-1),Anakkayam 1
, (BLA-139-1), Dhana (H-1608), Dharasree (H-3-17),
 K-22-1, kanak (H-1598),Madakkathara -1 (BLA-39-4),Madakkathara-2(NDR-2-
1),Priyanka (H-1591),Sulabha (K-10-2)
 Andhra Pradesh Varieties:BPP-1,BPP-2,BPP-3,BPP-4,BPP-5,BPP-6,BPP-8(H2/16)
 Karnataka Varieties:Chintamani-1,NRCC-1,NRCC-2,Ullal-1,Ullal-2,Ullal-3,Ullal-
4,UN-50
 Maharastra:Vengurla-1,Vengurla-2,Vengurla-3,Vengurla-4,Vengurla-5,Vengurla-
6,Vengurla-7
 Goa:Goa-1
 Orissa:Bhubaneswar-1
 West Bengal:Jhargram-1

11.  Ullal-1:It is a high yielding (19.6 kg nuts/tree) variety released for entire
Karnataka. This is an early bearing cultivar with high sex ratio (male: bisexual)
and high shelling percentage (30.7%).The size of the nut is medium. The
flowering commences from last week of November and extends up to middle of
March and harvesting is completed by May thus enabling to escape the
monsoon showers which otherwise results in the loss of crop. The variety has
144nuts per kg and medium sized apples with yellow colour.
 Ullal-2: This is another high yielding (17.9kg nuts /tree) variety released for
entire Karnataka. This variety also possesses desirable characters, such as, early
flowering and bearing, high sex ratio and high shelling percentage (30%) and as
such highly congenial for cultivation in hill zone. It has 164nuts/kg with
medium sized and yellowish red apple.
 Ullal-3: This variety flowers from November-January and the flowering period
extends for 60- 70days.The nuts can be harvested in January – March for nearly
60-90days.The average yield per tree is 14.68kg (at the 10th year) and the
shelling percentage is 30.00.

12.  Selections S-2 & S-3: These selections are released from National Cashew
Research Centre (South Kanara) for cultivation in Karnataka. They give an
average yield of 8-10kg nuts/tree with a shelling percentage of 29 BPP-5: It is a
selection from the Cashew Research Centre, Bapatla (Andhra Pradesh) and is
found to be the highest yielder (42.1kg dry nuts/tree on an average) with a
shelling percentage of 26.7

13. Hybrids
hybrids percent characters
Vengurla 3 Vengurla 1 x vetore 56 Cluster bearing
Vengurla 4 Midnapore red x vetore 56 Highest yielding high
yielding
Vengurla 5 Ansur early x mysore kotekar 1/61 High yielding
Vengurla 6 Vetore 56 x vengurla 1 High yielding
Bapatla 1 Tree 1 x tree 273
Bapatla 2 Tree1 x tree 273
Bapatla 3 Tree 1 x tree 39

14. soil
 The general notion is that "cashew is very modest in its soil requirements and can
adapt itself to varying soil conditions without impairing productivity". The best soils
for cashew are deep and well-drained sandy loams without a hard pan. Cashew also
thrives on pure sandy soils, although mineral deficiencies are more likely to occur.
Water stagnation and flooding are not congenial for cashew. Heavy clay soils with
poor drainage and soils with pH more than 8.0 are not suitable for cashew
cultivation. Excessive alkaline and saline soils also do not support its growth. Red
sandy loam, lateritic soils and coastal sands with slightly acidic pH are best for
cashew.

15. Climate
 Cashew is a tropical plant and can thrive even at high temperatures. Young plants
are sensitive to frost. The distribution of cashew is restricted to altitudes upto 700 m
above mean sea level where the temperature does not fall below 20°C for prolonged
period. Areas where the temperatures range from 20 to 30°C with an annual
precipitation of 1000 - 2000 mm are ideal for cashew growing. temperatures above
36°C between the flowering and fruiting period could adversely affect the fruit
setting and retention. Heavy rainfall, evenly distributed throughout the year is not
favourable though the trees may grow and sometimes set fruit. Cashew needs a
climate with a well-defined dry season of at least four months to produce the best
yields. Coincidence of excessive rainfall and high relative humidity with flowering
may result in flower/fruit drop and heavy incidence of fungal diseases.

16. Propagation
 Seed Propagation
Seed propagation is seldom practiced now except to raise the rootstock materials.
Seeds should be collected during the month of March to May and the heavy seed
nuts, which sink in water, are alone mixed with 2 parts of fine sand. They take
normally 15 to 20 days for germination..
 Vegetative propagation
 I. Selection of seed nuts
 1. Collect the nuts during heavy bearing period (Feb-April)
 2. Sun dry the nuts for 2-3 days
 3. Select the nuts which sinks in the 10 % salt (NaCl) solution
 4. Sow the nuts as early as possible, because after 6-8 months the germination
of seed nut get reduced. More than one year old seed nut should not be used
 5. Very big and very small seed nut should not be selected. Select only medium
sized nuts for sowing (130-150 nuts/kg)

17. Seed selection

18.  II. Production of root stocks
 1. Soak the seed nuts in water or cow dung slurry for 2 days or 10 %
Sodium hydroxide solution for one day to get higher germination
percentage.
 2. Sow the seeds in poly bags filled with potting mixture (25cm length,
13cm width and 250 gauge thickness)
 3. Make 30 to 40 holes in each polythene bag for easy drainage of
excess water
 4. Apply 5g of super phosphate per bag along with potting mixture
 5. Fill the poly bags with potting mixture till the margin and put dried
leaves or small stones at base for easy drainage of water
 6. Place the seeds at 2.0 to 2.5 cm soil depth and keep vertically in
which the stalk end of the seed nut facing top
 7. Apply water after sowing and daily with rose cane and avoid water
stagnation
 blight.

19.  8. Seeds germinate with 15 to 20 days after sowing
 9. Staggered sowing at weekly intervals facilitate to make the stocks
available continuously for grafting
 10. Provide shade to young root stocks; after greening of leaves keep the
stocks under open condition or remove the shade
 11. 40 to 50 days old root stocks are suitable for grafting
 12. During the germination, the cotyledon comes out of the soil and it is
tasty, therefore it will be damaged by birds, monkeys and other animals. So
during this period it should be watched carefully 13. During this period, the
root stocks will be affected by root rot and bacterial leaf blight disease
therefore to prevent the root rot apply 0.2% Thiram or Mancozeb and spray
for later apply 250ppm Streptomycin sulphate for bacterial blight.

20.  III. Selection of root stocks
 1. Good healthy seedlings, without side shoot, growing straight should be
selected
 2. Better to use the stocks raised in poly bags 3. Use the stocks age of 25-30
days for grafting

21. Selection and preparation of scion
 1. The scion providing mother trees should be grown with good fertilizer
application and better management
 2. The shoots from unbeared terminal shoots of 3 to 5 month aged should be
selected
 3. Select the scion of 10-12cm length, uniform pencil thickness with cream
coloured bud. The top 4 to 5 leaves of dark green in fully matured should be
selected. 90 days old scion only will be used for grafting purpose which gives
better graft uptake. The selected scion sticks should be precured by clipping off
leaf blades, leaving petiole.
 4. The new shoots of September- October month are not need any precuring of
scion but during other season retain the petiole of leaves with scion 5.
 Precurred scion can be used for grafting after 7-10 days. The petioles will shed
while touching with the fingers.
 6. The scion mother trees should not be allowed for flowering therefore during
flowering season panicles should be pruned

23.  V. Collection of scion
 1. Collect the scion from the precurred shoots because it will not dry quickly
and gives more graft uptake
 2. Collect the scion before the new flush come from the terminal bud
 3. Keep the scion separately on variety wise
 4. After cutting of scion roll with wet cloth and keep in polythene bag and it
can be kept for 1-2 days.
 VI. Preparation of stock for grafting
 1. In the selected root stock, trim all the leaves except two pairs of basal leaves
 2. Decapitated the stocks at 15cm height from the base
 3. Make a cleavage in the stock from top to 4.5cm in two equal portion

24.  VII. Preparation of scion for grafting
 1. Select the scion of uniform thickness related to root stock
 2. Make the length of the scion to 10cm if more lengthy
 3. Prepare a vedge shape of 4.5cm length in proximal end of the scion after
removing bark

25.  VIII. Grafting
 1. Keep the vedge shaped scion on the cleft of root stock
 2. Tie the union with polythene sleeves of 200 gauge thickness of 45 cm
length and 1.5cm width
 3. After tying of grafted stock, cover the top with 25cm x 4cm 200guage
poly bags, it prevents drying of scion
 4. Keep the grafted poly bags immediately inside the mist chamber for 15-
20 days
 5. After 15-20 days remove the poly bags placed over the grafts in inverted
position
 6. After 20 days remove the grafts from mist chamber and keep it in shade.
The grafting success could be seen within 3-4 weeks and scion will be
sprouted
 7. The grafts will be ready for planting within 5-6 months

27.  IX. Maintenance of grafts
 1. Apply water to grafts daily with rose can
 2. Prevent the water stagnation during rainy season
 3. Remove the polythene film used for joining the stock and scion after 45
days
 4. Remove the shoots comes out from stocks whenever emerges
 5. 60 days after grafting remove the leaves retained in the root stock.
6. Many of the grafts flower during flowering season. Therefore remove
panicle if grafts flowers
7. Change the place of grafts frequently and keep it in polythene lined floor
8. During the summer provide shade to the grafts and during rainy season
shade not necessary

28. Planting
 Pits of 45x45x45 cm are dug and filled with a mixture of top soil, 10
kg of farm yard manure and one kg of neem cake at a distance of 7m
x7m either way during June July and planted. In the case of seedling,
45 days old seedlings are transplanted.
Training and pruning
 All the side shoots must be removed upto a height of atleast 2m from
the ground to cause the branches to form and spread out from the
upper section of the trunk. Periodical pruning of dead wood and
cross cross branches during the month of July is recommended to
minimize the losses through diseases such as dieback and to increase
the yield.

29. Inter cropping
 Tall growing intercrops like certain varieties of sorghum and millet should
not be encouraged between young cashew, as they provide too much shade.
Leguminous crops such as groundnut and beans are very suitable for inter
cropping. Besides the annual crops, arid zone fruit crops having less canopy
especially annona, phalsa, etc., can be thought of, depending on the
suitability. Cultivation of horse gram, cowpea, groundnut etc is
recommended as inter-crops in cashew. Inter cropping cashew, Casuarina
and coconut are popular.

30. Cover cropping
 Cover cropping Leguminous cover enriches soil with the plant nutrients and
adds organic matter, prevent soil erosion and conserves moisture. The seeds
of these cover crops may be sown in the beginning of rainy season. The
seed beds of 30cm X 30cm size are prepared in the interspace in slopes by
loosening soil and mixing a little quantity of compost. The seeds of these
crops are sown in the beds and covered with a thin layer of soil. The seeds
should be soaked in the water for six hours before sowing.

31. Training
 Training is a method of regulating plant growth in a desired direction during early
years of planting, to form a definite canopy shape. Such type of initial training
provides good architecture to the plants and further helpful in good nut production.
In cashew, the training system and the diameter of canopy to be maintained is
dependent on spacing. In general, two types of training systems are being practiced
in cashew, a) Modified leader system and, b) Open centre system.
 a) Modified leader system
 In this system, cashew grafts are allowed to grow as single stem upto a height of 75
to 100 cm by removing side sprouts. Then lateral branches are allowed to grow at
desirable direction by de-topping. De-topping height varies from 2.5 to 4 m
depending on spacing. Under normal spacing (8m x 8m), de-topping at 4 m from
ground level is recommended. Whereas, for high density planting (5m x 5m), de-
topping at 2.5 m from ground level is recommended. Removal of cris-cross branches
and trimming of branches has to be resorted to get dome shape canopy and the same
should be maintained in later years by imposing mild pruning. This kind of canopy
helps in reducing week shoots and water shoots development. Modified training
system is suitable for both normal and high density planting system.

32.  b) Open centre system Cashew grafts are allowed to grow straight upto 50-60 cm
from ground level. The terminal growing point is pinched off to form lateral
branches. The branches are regulated to grow in four directions at equal distance.
Because of fast vegetative growth, the canopy spreads rapidly. To avoid this, canopy
centre needs to be opened once in a while to support more light interception to the
interior plant parts. This encourages flowering at inner and outer surface of canopy
and thus increases the yield.

33. Pruning
 Cashew plantation under normal or less spacing, requires regular pruning to avoid
unnecessary supply of photo similates to unproductive shoot i.e., water shoots and week
branches. In cashew, trimming of exhausted branches induce productive growth and helps
to promote the yield. In high density planting system, pruning operation plays a vital role
to accommodate the canopy within the allotted space. Pruning and canopy shaping along
with suitable special operations need to be taken up every year after harvest of the crop.
Cashew trees enter a distinct resting period (quiescent stage) after harvest (May – June)
till next flush production time (September - October). The lateral shoots which bears
flowers/fruits are formed in the terminal of leader shoot after resting period. The past
season leader shoots can produce only one lateral from its terminal. Pruning enhances the
production of lateral shoots, thus the yield can be improved

34. pruning

35. weeding
 The weed growth is seen maximum after the monsoon ( harvesting becomes
a problem if the weeds are not removed.(October-Novermber) The weed
growth is seen maximum after the monsoon ( harvesting becomes a problem
if the weeds are not removed. and Weeds are one of the most important
pests of cashew plantations. The main task after establishment of cashew
plantation is to control excessive weed growth which might otherwise
severely deplete soil moisture, compete for nutrients, pose a problem in
harvesting of nuts and apples.
 Depending upon the type of weeds and intensity of weed growth, weeding
is to be done manually, mechanically or chemically. The weed growth is
seen maximum after the monsoon ( harvesting becomes a problem if the
weeds are not removed.)

36. Weed management

37. Weed management
 Weeding around the young trees within a circle of about 1.5 m diameter by hoeing is
necessary during 2-3 years after planting. It is beneficial to weed the young trees
twice a year.
 The first round of weeding may be done, before heavy rains start, by uprooting the
weeds within the radius of 2m from the main stem .The remaining weeds in the
interspaces are slashed to ground level.
 The second round of weeding may be done during November-December to facilitate
spraying, harvesting and picking of nuts. In grownup orchards, careful weeding by
clearing the area within 2 m radius of the trunk and slashing the remainder is
essential until the trees shade out most of the weeds.


38.  Manual weeding
 Manual method like hand pulling, sickling and mulching are extensively
used wherever labour is available. Hand pulling is the most efficient in
annual and biennial weeds which are propagated by seeds. Sickling is done
to remove the tall growth of perennial weeds and to cut to the ground level
for a follow up application of foliage applied herbicides on the regrowth.
Mechanical weeding
 Mechanical hoeing may be carried over the whole-planted strip to a width
of about 4 m, leaving 2 m in both sides, to avoid root injury. Tillage
practices like hoeing, ploughing and mowing are done to clear off weeds,
especially in newly established orchards where sufficient spaces may be
available for intercultivation.
 Mulches like straw hay, farm wastes are used to cover the soil. They
produce heat which smothers or kills the weeds.

39.  Chemical weed management
 Chemical weed control is costly and thus reserved for exceptional cases,
especially in areas where the labour wages are high. Effective chemical weed
control methods are available for cashew plantations.
 Application of Paraquat @ 0.4 kg per ha twice at bi-monthly intervals starting
from July will effectively control all types of weeds.
 Application of paraquat twice costs Rs. 1700 per hectare ( @ Rs.0.4 kg ai
perhectare per weeding i.e., 2 litres of paraquat per hectare,@ Rs. 250 per litre,
500 litre of water per hectare, five men per hectare for spraying, wage Rs. 80
per day) whereas manual weed control twice costs Rs. 3000 per hectare (@ 25
women per hectare per weeding, labour wages @ Rs. 60 per day).
 Application of Glyphosate @ 0.8 kg per ha, in June–July can also control the
weeds effectively.


40. Chemical weeding

41. Manures and fertilizers
Age of plant Manures and fertilizers per tree
FYM or
compost
Nitrogen(N) Phosphorus
(P)
potassium(
K)
One year old
plant
10 50 25 25
Two year old
plant
20 100 50 50
Three year old
plant
20 150 75 75
Four year old
plant
30 150 75 75
Five year plant
or more
50 500 125 125

42. Better management practices may increase the yields marginally but boosting cashew production 3-4 folds in a short span of
time is perhaps possible only by "genetic transformation" of the existing plantations with high yielding varieties. It is
reported that this genetic transformation can be effected through top working. The rejuvenation of unthrift cashew
plantations through top working involves beheading of trees, allowing juvenile shoots to start-out and taking up of in-situ
grafting using procured scions of high yielding varieties. Periods from November to March and February to June have been
found to be ideal for beheading and in-situ grafting respectively. It has been observed that the top worked trees within a
period of two years have not only put forth a canopy of 3-4 m in diameter and 5-6 m in height (as that of 8-10 year old trees)
but also have given an yield of 3 to 5 kg nuts per tree in their first bearing itself

43. Harvest
 The cashew tree commences fruiting in the third or fourth year, attains the
full bearing age by the tenth year and lives for 40 to 50 years. Flowering
commences in November and extends upto February. The peak months of
harvest are March-April and the remaining crop comes to harvest in
February and May. The ripened will fall down and nuts from fallen fruits
have to be collected.

44. Harvesting of Raw Nuts
 At present harvesting of raw nuts is done in 4 ways.
 Collection after the natural drop
 Thrashing by stick and collection
 Climbing the tree and thrashing, and
 Shaking the branches
 About 70 per cent of the farms follows thrashing by stick and collection method.
Certainly, this will increase the percentage of immature nuts supplied to the industries.
Only 15 per cent of farms follow the collection of nuts after the natural drop. Climbing
the tree and thrashing and shaking the tree to harvest the nuts amounts to 10 per cent and
5 per cent respectively. These two methods undoubtedly increase the immature nuts
harvest and lead to inferior quality in final produce. harvest and lead to inferior quality
in final produce.
 B Harvesting y thrashing or climbing also results in dropping of young flowers and
ultimately reduces the production. It is a usual practice to harvest nuts just before
they mature because of theft incidences. This is not a good practice because it
results in poor quality of the kernel.

46.  It is desirable in the interest of both the growers and cashew industry that nuts must be
harvested only when the apples are fully ripe. The colour of the nuts changes from brownish
green at fruit set to light green at 1/4 of the apple development and thereafter turns grey
irrespective of varieties. This is the right time to harvest the nuts. Farmers should be educated
in these aspects to avoid immature nut supply to factories.
 Best quality nuts are obtained where freshly fallen fruits are collected, the apples are removed
and the nuts are sun-dried for 2-3 days to reduce moisture from 25 per cent to below 9 per cent.
It is essential to dry the nuts after harvest to prevent spoilage during subsequent storage. By
proper drying, the kernels retain their quality, in particular, the flavour.
 The mature nuts will sink in water while the immature/unfilled ones will float. This test could
be used to find out whether the nuts are mature or not. Nuts should be gathered at weekly
intervals during the cropping season.
 However, if cashew apples are used for processing, it is better to harvest them from the tree
without damaging the apples. Ripe apples for fresh use should be picked almost daily. The area
under the tree should be weed free and swept clean to facilitate nut collection.
 Though cashew plants commence flowering one year after planting, fruiting should be allowed
only from third year onwards.

47. Nut Yield
 The yield of cashew nuts varies from 0.5 kg to 25.0 kg per tree depending on the age
of the tree, ecological conditions, management of the plantation and the varieties
planted.
Tree age Nut yield
3 year 0.5
4 year 2.0
5 year 4.0
6 year 6.0
7 year 8.0
8 year and above 10.0 -25.0

48.  Infertile soils, about 1000 to 1500 kg of nuts/ha can easily be harvested, maintaining
the plant population of 156/ha with 8m x 8m spacing. With high yielding varieties,
proper spacing and good maintenance of the plantation, it is possible to get about
3.0-5.0 tones nuts per hectare from 10-15 years old trees.

49. Post harvest practices
 Cleanliness and raw nut moisture content in the drying yard and storage godown are
of prime importance. Utmost care has to be taken regarding the cleanliness of these
two places to avoid any foreign matter entry leading to spoilage.
 During drying, turning of nuts at regular intervals for uniform drying and moisture
content has to be determined.
 As far as possible, drying on a finely finished floor has to be avoided as this may
increase nut temperature, sufficient enough to burst cashew nut shell liquid structure
and diffuse it into the kernel leading to inferior quality in final produce. Therefore,
nuts should be dried on the semi-finished rough floor to overcome this problem

50.  The warehouse for raw nuts has to be given particular care so as to
maintain nuts at safe moisture levels by controlling the environment of
the warehouse. This can be achieved through proper ventilation. Use of
new or fumigated gunny bags is an effective measure against insect
infestation.
 Gunny bags with nuts have to be stacked to a limited height to avoid
heavy load on the lower bags leading to dampness. There should be
free space between two stacks in a row for sufficient aeration.
 The storage life of raw nuts in the godown also depends on the quality
of nut and its environmental condition during storage. Fluctuating
temperature is deleterious during storage due to condensation of
moisture in the godowns in certain pockets and consequent microbial
growth.
 Atmospheric relative humidity (RH) plays a key role in the safe storage
of raw nuts as the nuts absorb or desorb moisture to maintain
equilibrium with the atmospheric relative humidity.

51. Dry and storage
 Thereafter the viability reduces rapidly within the next 6 months. Seednuts stored in
gunny bags loses viability completely at the end of 11 months from the harvest in air
tight containers.
 For good keeping quality and for yielding good quality kernel, it is essential that the
nuts are dried. The moisture level of 8-9% is considered ideal.
 In most cases, the nuts before being stored are dried in the sun and re-packed. The
dried nuts not only stand well but also give a fairly good product.
 The nuts are generally stored in godowns in gunny bags. The nuts are resistant to
insects and it is found that the nuts stored for a period up to six months after
harvesting do not suffer from any infection or deterioration in quality.
 Nuts can be stored up to 8 months

53.  Grading
 Grading of raw nuts before processing is an important aspect to be taken into
consideration.
 The ultimate aim in cashew processing is to get whole kernels.
 Quality Standards in Raw Cashew nut
 Quality standards for raw cashew nuts have to be formed irrespective of whether the
procurement is from domestic or foreign sources. The following points have to be
considered to maintain the quality of raw nuts.
 Floaters should be as minimum as possible.
 Sufficiently developed and with full ripeness or maturity.
 Free from living insects or mites whatever their stage of development and visible
damage by insects, mites or parasites.
 Specified moisture content.

54. Grading

55.  In order to maintain the quality of raw nuts for successful processing: farmers have
to be educated on method and stage of harvest, the price of nuts has to be fixed on
the basis of size of nuts and its moisture content, the high degree of cleanliness has
to be maintained in drying yard and storage godown.
 Raw nuts in warehouses should be monitored at regular intervals for its quality and
it should be provided with ventilation and sufficient aeration.
 Processing
 Raw nuts required for processing are purchased by the processing units. The nuts are
sun-dried for 1-2 days to reduce the moisture content from 16 per cent to 8-9 per
cent and stored in gunny bags in the godown.

57.  Roasting
 Roasting of raw nuts is done to separate adhering shell from the kernel. There are
three types of roasting viz., Drum roasting, Oil bath roasting and Steam roasting.
 Steam roasting
 Steam roasting is the commonly used method by most of the processing units. In
steam roasting, the raw nuts are steam roasted at about 100 lb pressure for about 25-
30 minutes. The treated raw nuts are spread on the floor and allowed to cool for 24
hours and then sent to the shelling section the next day. The turnout and appearance
of whole kernels from raw nuts treated in this method are said to be better than any
other method. The cashew nut shell liquid obtained from the shells are very clear
and command a premium price. About 75% of cashew nut shell liquid can be
extracted from the shells.

59.  Drum roasting
 In this process, the nuts (without any conditioning) are fed into a
rotating drum which is heated initially to red-hot condition to
allow the shell portion of the nut to ignite and burn. Once ignition
starts no further heating is necessary and the drum maintains the
temperature on its own. Excessive heating leads to oozing of oil
from the shell.
 In this method of roasting the shell becomes very brittle and the
rate of shelling and out-turn of the whole kernel is higher
compared to other methods. The roasting generally takes about 3-
5 minutes and the drum is rotated by hand. The roasted nuts
which are still burning are removed from the discharge end and
immediately covered by ash to absorb the oil that is found on the
surface. Kernels obtained in this process have a better colour.

61.  Conditioning
 Before being processed, the nuts are required to be conditioned to an optimum moisture level so as to make
the shell soft and to break the oil-bearing cells to yield the maximum amount of shell oil during roasting. The
method of conditioning followed at present is given below.
 The nuts are cleaned by passing them through a perforated rotating drum to remove dust and foreign matter
and are later washed by dipping them in cold water in a tank. Then they are heaped on the floor or stored in
iron tanks for 24-72 hours and during this period water is sprinkled over the heaps periodically to keep the
nut in a wet condition and allow it to absorb moisture gradually.
 The quality of the final product is entirely dependent upon the initial conditioning of the nut. Different
factories follow different conditioning methods and periods. The optimum treatment is subjectively decided
by a feel of the nuts.
 If the nuts have not absorbed a sufficient amount of water, the oil recovery is less and results in broken
kernels. On the other hand, if the nuts are over-conditioned this results in discoloration of the kernel and
such kernels fetch lower prices.
 The processing of raw nuts involves roasting, shelling, drying, peeling, grading and packing. The steps
involved in the commercial processing of cashew nuts are detailed below:

62.  Oil bath roasting
 In this process, the conditioned nuts are allowed to pass through a bath of heated
cashew shell liquid maintained at a temperature of approximately 350-400 F for
about 1-2 minutes. The roster consists of a rectangular vessel with or without a
semi-circular bottom in which there is either a screw or belt conveyor operating
inside the bath of liquid. The vessel is embedded in brickwork and heated by a
furnace for which spent shell is used as fuel. By adjusting the speed of the
conveyor it is possible to adjust the roasting time.
 During the passage, the shell gets heated, cell wall ruptures and the shell liquid
is released. It is estimated that more than 50% of the shell liquid is released by
this means. The nuts are then conveyed by a warm screw through a suitable
outlet to a centrifuge where the residual oil adhering to the surface of the shell is
removed by centrifuging. The nuts are then mixed with ash and sent for
shelling. The oil overflowing from the roasted nuts and the oil recovered in the
centrifuges are both conveyed to a tank and filled into drums before despatch.

63.  Sun Drying
 Simply dried in the sun for 2 to 3 days and shelled without roasting.
 Shelling
 After roasting and cooling cashew nuts are shelled to remove kernels. One has to be very
careful while shelling the nuts. Hands are to be protected from CNSL which is highly
corrosive. It is a normal practice to use hand gloves while shelling. For the same reason,
it is advisable to dust nuts with wood ash.
 Commercial processing units use foot operated shell cutters (mechanical device) for
shelling. This device consists of a pair of blades (knives) shaped in the contour of half a
nut which could be operated by foot. The nuts have to be grouped into various sizes, each
size matching a pair of blades of appropriate size. The blades cut through the shell all
around the nut, leaving the kernel untouched. After shelling, the kernels and shell pieces
are separated manually.
 In most of the factories shelling of roasted nut is done manually for which women labour
is employed. The nuts are knocked 2 to 3 times on each of the long edges of the oval-
shaped nut by wooden mallets or light hammers taking care to see that whole kernels are
released and damage or breakage to kernels is avoided as far as possible.

64.  The nuts have been given only a mild roasting and all the shell oil is intact.
Therefore, during the cutting and de-shelling, the released oil comes in direct
contact with the skin of the workers and the kernel. There is no scope for applying
ash or any other material to reduce the corrosive action of the liquid. The workers,
therefore, dip their hands in castor oil periodically, to minimize the corrosive action.
 Cutting and de-shelling require more skill than de-shelling by mallets for, because of
the uneven sizes the nuts have to be conveyed and kept in position at the cutting
edges by hand and even well-trained workers are stated to injure their hands
sometimes.
 From 100 kg of raw cashew nuts, about 22-24 kg whole can be obtained and the
broken kernels will be about 3-4 kg.

65.  Drying of Kernels
 The kernels after shelling will have a moisture content of 6 per cent. Drying of these
kernels is necessary to prevent fungus attack during subsequent storage and to
facilitate peeling of testa.
 The kernels are to be dried to a moisture content of about 4-5 per cent. This is done
by drying the kernels in hot chambers at 70-80 C in perforated trays for about 6-8
hours. Uniform drying could be achieved with a cross flow drier using forced hot air
circulation through the kernel layers.
 In order to ensure uniform drying, the position of the trays has to be changed
frequently, as scorching may occur at hotter places. Excess drying of kernels leads to
kernels becoming very brittle resulting in higher breakage. After drying, the kernels
are kept in the moist chamber for 24 hours which facilitates easy removal of testa
(peeling) and minimizes broken kernels.

66.  Peeling
 This process involves the removal of testa (seed coat) from the kernel. Peeling is
done using a sharp knife or bamboo piece. Care has to be taken while removing the
testa. If kernels are scratched more it results in poor quality kernels.
 Sweating
 The cleaned kernels are further subjected to a process of sweating to prevent
breakage. They are placed in iron mesh trays and the water stream is passed through
the tray to make the kernels tough.

68. Diseases
 Die – back or Pink disease: Corticium salmonicolor
 Damping off: Phytophthora palmivora
 Anthracnose: Colletotrichum gloeosporioides
 Inflorescence blight: 24.0%mangiferae and Phomopsis anacardii
 Shoot rot and leaf fall : Phytophthora nicotianae var. nicotianae

69.  Inflorescence blight :Gloeosporium gloeosporioides
 Symptoms:
 This is also a common disease in Kerala especially during the monsoon period.
 The characteristic symptom is the drying of floral branches. The symptoms
appear as minute water soaked lesions on the main rachis and secondary
rachis.
 The lesions are pinkish brown, enlarge and soon turn scabby. Gummy exudates
can be seen at the affected regions.
 The lesions develop into bigger patches and result in drying up of the
inflorescences. The incidence is very severe when cloudy weather prevails.
 Management :
 A combination spray of a fungicide (Cuman L 100 ml in 100 litres of water or
Blitox 250 g) and an insecticide Dimecron (30 ml in 100 litres) is
recommended.
 It is often claimed that the primary cause of the disease is the tea mosquito and
fungi'are only secondary organisms.

71.  Anthracnose: Gloeosporium gloeosporioides
 Symptoms:
 The disease has been reported in an epidemic form from Tamil Nadu. It
is known to cause severe loss in Brazil.
 The fungus infests the tender leaves, twigs and forms redddish brown,
water-soaked lesions. On the affected region exudation of resin can be
seen.
 The lesions enlarge and kill the shoots. The tender leaves are crinkled
and fruits shrivelled.
 The infected inflorescences turn black. Repeated Infection of the
terminal shoots leads to the death of the tree in course of time.
 Management :
 Destroy all affected branches
 Spray the plants with 0.5% Bordeaux mixture or Mancozeb 0.25%

73.  Shoot rot and leaf fall : P. nicotianae var. nicotianae
 Symptoms:
 During the south west monsoon months of June - August extensive leaf fall and
shoot rot symptoms are observed.
 Black elongate lesions are first developed on the stem with exudation of gum. Later,
infection spreads up and down, causing the tender stem to collapse and tender leaves
to shrivel up.
 The lower mature leaves are also infected with black elongated lesions on mid rib,
which later spread to the main lateral veins and the leaf blade.
 The infected leaves are soon shed.
 Management:
 Spraying with Bordeaux mixture (l %) before the onset of monsoon will check the
spread of the disease.

74. Pests
 Stem and Root Borer.
 Tea Mosquito Bug.
 Leaf Miner.
 Shoot and Blossom Webber.
 Apple Borer.
 Inflorescence Caterpillar.
 Thrips
 Bark Borer. Minor Pests.

75.  Stem borer
1. Collection and destruction of affected shoots
2. Swabbing the bark of exposed roots and shoots with Carbaryl 50 WP
2 g/lit. Twice a year before the onset of South West Monsoon (March –
April) and after cessation of monsoon (November) painting of coal tar
+ kerosene mixture (1:2) or swabbing with a suspension of Carbaryl 50
WP (4 g/lit) can be done up to one metre length in the exposed trunk
region after shaving the bark or swab the tree trunk with neem oil 5%
thrice during January February, May-June, and September-October..
3. Root feeding with Monocrotophos 36 WSC 10 ml + 10 ml of water
kept in a polythene bag on one side of the tree and keep the same
amount on the other side of the tree (Total 20 ml/tree) divided into two
equal halves will give protection when there is moderate incidence.
4. Remove grubs from early stage infested trees and drench the damage
portion with Chlorpyriphos 0.2% @ 10 ml/lit or Neem Oil 5%.

76.  Tea mosquito bug
 Spray application of phosalone 35 EC@ 2.0 ml, followed by carbaryl 50WP @
2g/l and monocrotophos @ 2ml/l at vegetative flush stage, panicle initiation
stage and nut formation stage respectively are recommended for the
management of tea mosquito bug.
 Spray schedule involving three rounds of spray viz., first spraying with
Profenophos (0.05%) at flushing stage, second spraying with Chlorpyriphos
(0.05%) at flowering and third spraying with Carbaryl (0.1%) at fruit set stage is
most effective.

77.  Shoot caterpillars
Shoot caterpillar can be controlled by spraying Profemophos 50 EC @ 2 ml/lit.
 Root borer
Root borer can be controlled by pouring Monocrotophos 10 ml/tree in the bore
holes (Insecticide 5 ml + 5 ml water).
 Leaf miner
1. Collect and destroy the damaged plant parts
2. Spray NSKE 5% two rounds, first at new flush formation, second at flower
formation

78. THANK YOU