Cashew Plants

4. Vegetative propagation of cashew plants

Most of the older cashew plantations are established by utilisingthe seedling progeny. These are not homogeneous and are variable intheir performance. In order to overcome this problem, it has beensuggested to establish new cashew plantations with clonal materials.Varieties having bigger nuts with mean yield of more than 15 kg per treeper year with other desirable characters should be selected formultiplication. Air layering and grafting are the two methods availablefor vegetative multiplication.

4.1. Air layering

Select well matured branch of finger thickness keeping about30-40 cm length. Carefully remove 2.5 cm width bark from lower end ofthe selected branch. Overnight soaked crushed coir husk or coir pith orsaw dust is tied with the help of plastic sheet/ thin gunny cloth to alength of about 10 cm (Fig. 2). Roots appear within 45-60 days. Plastic

Fig. 2: Air layering in cashew

sheet should be used for summer and gunny cloth during the rainyseason. When the roots are properly seen give a partial cut at the baseand further deepen after a week. Cut and separate after another oneweek.At the time of separation clipping of the leaf blades leaving behindthe petiole stubble is desired. The rooted plant could be immediatelyplanted or could be kept in nursery at 50 per cent shade by planting ina suitable poly bag. While planting the air layered plants, care shouldbe taken to see that they are planted deeply without causing any damageto the adventitious roots as they are devoid of primary root system.This method could be easily followed by farmers to propagate highyielding varieties of their choice.

4.2. Soft wood grafting

i) To grow root stocks for the purpose of grafting, seeds shouldhave proper vigour during germination.

ii) The seed selected should not be empty and should contain a fullkernel.

iii) Medium sized nuts should be selected for the purpose.

iv) The seeds selected should be properly dried and soaked for aday in water (or Bijamrutha-see Annexure-1)

v) Polythene bags (25 cm x 15 cm size, 300 gauge thickness) areutilized for raising the rootstocks.

vi) The polythene bags should be filled with soil mixture containing1/3 each of compost, sand and soil along with 5 g of bio-fertilizers.(Varanashi Composter can be used).

vii) Seeds should be sown with their stalk-end upwards and shouldbe just covered with soil. After sowing, soil surface should becovered with some mulching material.

viii) Germination will be seen after 15 days. The cotyledons shouldbe protected from birds and children.
ix) About 45-60 days old seedlings are utilized as root stocks.

x) From a selected variety, lateral shoots of current season whichare non flowered, 3-5 months old and pencil thick having prominentterminal bud are selected and pre-cured on the mother tree byclipping off leaf blades, leaving behind the petiole stubs. After10-15 days these pre-cured shoots are collected and utilized asscions for grafting.

xi) The root stock is prepared by removing all the leaves except twopairs of bottom ones. The terminal growth (soft wood portion) at aheight of 15 cm from the ground level is decapitated and a 5-6cm deep cleft is made in the stem.

xii) The pre-cured scion stick which is freshly separated from themother tree is mended into a wedge shape of 5-6 cm length bychopping off the bark and a little portion of wood from two oppositesides, taking care to retain some bark on the remaining two sides.

xiii) The wedge of the scion is inserted carefully into the cleft of theroot stock taking care to see that the cambium layers of both theroot stock and scion come in perfect contact with each other.

xiv) Then the graft joint is secured firmly with a polythene ribbon(1.5 cm wide, 30 cm long and 100 gauge thick).

xv) A long and narrow white polythene cap (20 cm x 4 cm size and200 gauge thick) is inserted on the grafted plant. This protectsthe apical bud from drying up and enhances sprouting (Fig. 3 and4). In case of Vietnamese method, gumless thin cellophane tape(generally used to cover vegetables) is used to secure the jointand the same is used to wind and cover the scion upto the tip(Fig. 5).

xvi) The grafting should be done under shade in the nursery shed andthe grafts are to be kept in the shade for about 15 days.

xvii) Before shifting the grafts to the open area or dismantling polyroof, the polythene caps should be removed. These grafts are tobe maintained in the nursery till the next planting season. Duringthis period the side shoots arising from root stock should beremoved. The polythene ribbon tied to the graft joint should beremoved after 3-4 months and later on the grafts should be shiftedto an open area in the nursery. Alternately, if poly sheet roofing ismade, instead of shifting grafts, it is convenient to remove thetemporary shade roof to allow the sunlight to fall on the grafts.

xviii) They will be ready for planting after 5-6 months of grafting.Generally grafting season and planting season coincide in the caseof cashew. High rate of graft success is observed in April - May grafting.The success is also satisfactory during monsoon season due to theavailability of mature scion sticks. Generally cashew grafts producedduring monsoon season are to be maintained in the nursery till the nextplanting season (monsoon).

Generally grafting season and planting season coincide in the caseof cashew. High rate of graft success is observed in April - May grafting.The success is also satisfactory during monsoon season due to theavailability of mature scion sticks. Generally cashew grafts producedduring monsoon season are to be maintained in the nursery till the nextplanting season (monsoon).

Fig. 3: Various stages in soft wood grafting

Fig. 4: Grafted cashew plants covered with polythene caps

In a few comparisons that have been made, grafted trees have grown better and fruited earlier than the seedling trees of similar age. However, once the soft wood grafts are planted in the field, it is necessary to give adequate care to establish a proper orchard and derive benefits from vegetatively propagated materials of high yielding varieties

Fig. 5: Soft wood grafting – Vietnamese method

4.3. Whip or splice grafting

Pre-cured scion of about 10 cm length is given a slant cut of2.5-5.0 cm on one side. Matching cut is given on the apical portion ofthe stock seedling about 15 cm above base retaining 4 leaves (Fig. 6).The cut surfaces of both scion and stock are matched together andtightly wrapped with a polythene film from the joint upto the top asexplained in Vietnamese method (4.2 - xv). The terminal bud of scion

Fig. 6: Stages of whip or splice grafting

sprouts within 3 weeks breaking open the thin plastic film. Care shouldbe taken to see that the basal portion of the stock does not give sprouts.In Vietnam, whip or splice grafting method is mostly practiced

5. Land preparation
Wild growth particularly forest tree growth should be cleared fromthe site selected for cashew cultivation. The roots of the weeds andbushes should be completely uprooted around 2 m radius of the plantingpit. This ensures competition-free environment for the newly plantedcashew grafts. In the absence of inter crops or cover crops the space inbetween the plants could be cleared in phased manner in the subsequentyears. Cashew is a sun loving plant, and there should not be any shadeover the plant.

6. Digging of pits
Pits of 1 m x 1 m x 1 m dimension should be dug. A spacing of7 m x 7 m or 8 m x 8 m or 10 m x 5 m is ideal depending upon thevariety and type of land used. In case of vigorous growing variety, spacingcan be 8 m x 8 m and in case of less vigorous variety, it can be7 m x 7 m or 10 m x 5 m. If the soil is more fertile, more spacing shouldbe adopted. If there is a hard pan, then bigger pits should be opened toa size of 1.2 m x 1.2 m x 1.2 m. Hedge row system of planting with aspacing of 10 m x 5 m will be beneficial for growing intercrops duringthe initial period. The pits should be dug out 15 to 20 days before plantingand exposed to sunlight so as to get rid of soil borne pests. Later twothird portion of the pits are to be filled with a mixture of top soil, 6 kg ofcompost, 20 g bio fertilizers (N.fixers and P.solubilizers or VaranashiComposter) and 200 g rock phosphate

7. Planting
Since cashew is a rainfed crop, planting is usually done duringmonsoon season. However, in heavy rainfall areas the planting may bedone once the heavy rains are over. Plants multiplied by vegetativemethods are preferred because they give higher yields. The graftsprepared using scion sticks of high yielding mother trees behave likethe mother plants. While establishing cashew garden, instead of a singlevariety it is preferable to go for two to four varieties having middle andlate season flower bearing habits. To prevent pest problems, it is betterto avoid early season flowering varieties. Healthy ones should be planted

Fig. 7: Planting cashew grafts

Fig. 8: A properly planted cashew graft with staking

after carefully removing the polythene bags without disturbing therhizosphere soil. Soil at the centre of the pit should be scooped out forplanting. After placing the plant in the pit, the soil around the pit should be pressed gently. In case of grafts, care should be taken to see thatthe graft joint is at least 5 cm above the ground level. This clearance willhelp to locate and remove the sprouts on the root stock below the graftjoint (Fig. 7 and 8). The remaining one third portion of the pit should begradually filled up to the ground level within 2 years.

7.1. Staking and mulching
After planting the graft, a stake should be provided to support theplant and loosely tied to plant with a jute thread (Fig. 7). This preventsdamage to the graft joint due to heavy wind. The soil around the plantshould be covered with thick mulch of green or dry leaves for better soiland moisture conservation

8. After care, training and pruning
Side shoot growth below the graft joint should be removedperiodically. Emerging side shoots above graft joint should be removedby secateure up to 50-75 cm height of the stem. There should be aclear single stem up to 50-75 cm height. This should be attained byremoving the lower branches in stages so that the tree should haveenough strength to withstand heavy wind. Single stem at base facilitateseasy cultural operations, nut collection, and surveillance of CashewStem and Root Borer (CSRB) infestation. New and longer stakes shouldbe provided after removing old and weaker ones during the second andthird year after planting. De-blossoming should be carried out for thefirst two years after planting. Further, regular pruning of weaker branchesin the initial years of growth encourages the establishment of goodframe work (Fig. 9). Third year onwards flower panicles need not beremoved.After 3-5 years, main branch which is growing vertically shouldbe beheaded at a height of 2.5 m to 3.5 m. This is to reduce overshading effect of higher branches on the lower branches. Thisencourages better spread of the canopy as well as uniform distributionof light on all the branches.The ideal period for pruning would be after the nut harvesting andbefore the onset of new shoots. This could be taken up at the end ofMay or beginning of June. When large sized shoots are pruned, careshould be taken to see that the cut surface is as smooth as possibleand hence sharp blades should be used. Cut portion should be swabbedwith 10 per cent bordeaux paste.

Fig. 9: Pruned young cashew plant

9. Soil and water conservation methods
Cashew being mostly an unirrigated crop, requires proper soil andmoisture conservation measures. In slope area, terracing should betaken up around each plant within second year (Fig. 10). Initially terracewith inward slope should be made and a catch pit of2 m x 0.3 m x 0.45 m (l x b x h) at a distance of 1.8 m-2 m away fromthe base of the plant on the upper side of the slope should be dug. Theterrace and trench could also be constructed in semicircular pattern.On a level land, square circular or staggered trench of 0.3 m depthshould be dug and the soil is spread around plant basin (Fig. 11 and12). After the earth work, the soil around should be mulched with organicmatter. This prevents erosion during rainy season and avoids directexposure to sunlight thereby efficiently conserving soil moisture insummer (Fig. 13).

10. Manuring
In organic farming system, nutrients should be given in an organicway. A grown up cashew tree produces about 20 kg of biomass wasteper year (biomass waste - cashew leaf litter, prunings, waste cashewapples etc.). This should be returned to the soil. In addition, 5-8 kgcastor cake or 10 kg FYM or 5 kg poultry manure with 50 g bio-fertilizersshould be applied when there is optimum soil moisture. Manureapplication should be taken up in the beginning of monsoon (June) atlow rainfall areas and in mid monsoon (August) in high rainfall areas.Addition of bio-fertilizers namely N-fixers and P-solubilisers also givesbenefits. If Varanashi composting method is used, additional dosage ofbio-fertilizers is not required. For young plants, the dosage starts fromone fifth of recommendation and increases year after year till fifth year.

After the application of organic manure around the trees, it should becovered by a thin layer of soil and properly mulched. Periodic spray of


Fig. 10: Providing catchpits for young cashew on sloping land(drawing and photograph)
Fig. 11: Circular catch pit at a distance of 3 m from the trunk of an old tree

Fig. 12: Circular catch pit for old cashew tree on level land
Fig. 13: Mulching of cashew tree with dry leaves

cow’s urine (1:10 dilution) or compost tea (1: 40 dilution) facilitatesbetter growth. They also prevent pest and disease attack.

When there are plants of more than 20 years age in an orchard,pits of 1.0 m length, 1.0 m breadth and 0.5 m depth should be dug atthe centre of the four trees and cashew biomass with fruits are to beincorporated into the pits along with organic manure and bio-fertilizers.Cow dung slurry at 20 per cent of the total biomass should be added toit and covered by a thin layer of soil. May is the ideal month for carryingout this operation. Some of the roots of old trees may get exposed andbecome vulnerable to CSRB attack hence these roots should be coveredby thin layer of soil.

10.1. Alternate manures
In view of rising demand for organically grown cashew, strategiesneed to be developed for organic farming for different agro-ecologicalzones because organic manure availability may vary according to differentlocations. Some of the commonly available organic manures like poultrymanure, farm yard manure (FYM), vermicompost, oil cakes, coir pith,organic manure mixtures etc. hold promise in organic farming in cashewas per the results obtained at National Research Center for Cashew.There is high potentiality to utilize cow dung slurry in major cattle rearingareas. In addition to the above manures, poultry litter and oil cakes arealso available in huge quantities in most of the states. Green leaveswhich are in abundance in Kerala, coastal Karnataka and Maharashtra, where cashew is mostly grown also serve as good organic manure tocashew. Green manure crops like gliricidia and pongamia can be grownvery well under rain fed conditions on the border or inside cashewplantations to produce green manure.

While considering the quantity of nutrients available in soil, theapproximate quantity of organic manure required to meet therecommended dose of Nitrogen of 500 g per tree is presented inTable 2. The recommended dose of Nitrogen has been arrived at, basedon the trials conducted in various research stations. In organic manure,availability of nutrients normally stretches for a longer period and inaddition the loss of nutrients through leaching is least

If the nutrients are applied through chemical fertilisers hardly50 per cent of nitrogen and 75 per cent of the applied potash (K2O) willbe made available to the plants due to nutrient loss through seepage,runoff and denitrification. Such nutrient loss is negligible in the case oforganic manures. Detailed studies need to be taken up for suggestingoptions to farmers like, the exact quantity of different organic manuresto be applied per tree depending upon the availability of these manuresin the respective locality.

The quantity of organic manures mentioned in Table 2 will meetthe full requirement of Phosphorous (P2O5) and Potash (K2O) in all casesexcept in green manure and groundnut cake. When these are used,bone meal and wood ash may be suggested to supplement P2O5 andK2O requirements for producing cashew organically.

Table 2: Quantity of organic manures required for adultcashew tree (kg/tree)

11. Cover cropping
Leguminous crops such as Pueraria javanica, Calopogoniummucunoides and Centrosema pubescens enrich the soil nutrients, addorganic matter, prevent soil erosion and conserve soil moisture. Seedsof these cover crops can be sown in the beginning of rainy season atthe rate of 12 kg per ha in the interspace of cashew orchard. Beds of30 cm x 30 cm are prepared in sloppy degraded soils by loosening thesoil and mixing compost or cow dung. Then the seeds are sown in thebeds and covered by a thin layer of soil. Presoaking of the seeds inwater for six hours ensures better germination. Fencing is necessaryto avoid cattle grazing. Gliricidia maculata can be grown in the interspacebetween two rows of cashew or all along the border (Fig. 14). If it isgrown in the interspace it may be spaced at one meter distance. Threerows of gliricidia can be grown in the interspace of two rows of cashew.Gliricidia may be grown by sowing seeds or planting stem cuttings ofone meter length during rainy season. Nearly 60 kg leaf and tenderbranches can be collected and applied to each cashew plant as greenleaf manure (Fig. 15).

12. Intercropping
Leguminous crops like horse gram, cowpea, and other crops suchas ground nut, tapioca, vegetable and fodder crops, elephant-foot yam(Fig. 16 and 17) are grown as intercrops in cashew plantations. Amongthe various annuals, biennials, fruit crops and tree species, pineapplehas been found to be the best when grown as inter or mixed crop(Fig. 18). In cashew garden for the first seven years, pineapple couldbe grown in the interspace between two rows of cashew. Three trenchescould be opened in between the rows across the slope. Size of trenchshould be 1 m x 0.5 m (width x depth) and of any convenient length. Ineach trench two rows of pineapple suckers should be planted at 60 cmbetween rows and 40 cm between two suckers within the row. For onemeter length, half basket of compost should be added and mixed withsoil before planting suckers. One hectare cashew orchard canaccommodate 15,000 suckers. Pineapple starts yielding from secondyear and after fourth year, it should be replanted in a new trench dug outby the side of existing trench or the same could be retained till seventhyear of cashew plantation. After seven years, because of heavy shadeof cashew tree over the pineapple and due to difficulty in picking rawcashew nuts fallen over pineapple plants, it may not be feasible to grow

Fig. 14: Gliricidia in between cashew plants as a green manure crop

Fig. 15: Application of gliricidia branches and leaves as green manure tothe cashew plants

this intercrop economically. Nearly 40 tons of pineapple fruits can beexpected over a period of seven years with a gross return of aboutRs. Two lakhs. Expenditure would be Rs. One lakh and hence net profitfrom pineapple alone will be Rs. One lakh per ha of cashew garden.Apart from giving an additional income, 30 per cent increase in cashewnut production was also observed mainly due to better soil and waterconservation in the trenches, where pineapple is planted across the

Fig. 16: Tapioca intercrop with cashew

Fig. 17: Elephant foot yam in between cashew plants

Fig. 18: Inter cropping pineapple in cashew orchard

slope between two rows of cashew.

Other crops like turmeric, ginger and elephant foot yams can begrown as intercrops organically for the first 5 years of planting cashew.The profit realized from these crops may range from Rs. 20,000 toRs. 50,000 per year.

13. Mixed cropping
It is not possible to achieve sustainability by growing only oneparticular type of crop. Whatever is the size of the holding, growing avariety of crops within the available land contributes to the ecologicalbalance. While selecting mixed crops its compatibility with the maincrop, spacing, and availability of light, manure and water requirementshould be properly studied. Mango, sapota, kokum, amla, jack fruitetc. could be grown as mixed crops in cashew orchards (Fig. 19). Incountries like Malaysia, Indonesia and Cambodia, rambutan, longon,dwarf bamboos are grown with cashew by providing proper spacing foreach crop according to canopy coverage. Considering various mixedcrops grown in different cashew growing areas and from the experimentsconducted at NRCC Puttur, some of the promising combinations ofcrops are listed below. Nevertheless, farmers are advised to studycarefully various aspects of cultivating mixed crops in their locationsnamely suitability, irrigational requirements, marketing avenues etc.

vision Fig. 19: Mixed cropping of sapota, mango and cashew

before adopting them in their orchards. Some of the crop combinationsalong with spacing recommended for each crop in high densitymultispecies situations are given below.

1. Between two rows of cashew, the spacing maintained is 30 m. In themiddle of two rows planting mango, tamarind, silk cotton, jack,sapota, amla etc. at a uniform distance of 10 m (as shown in Fig. 20)would give additional income. These crops do not require irrigation.But timely pruning of these trees would be highly beneficial afterseven years of planting. Catch pits help in the conservation of soiland water.

2. Between two rows of cashew the spacing maintained is 21 m. In themiddle, two rows of planting with guava or longon and rambutan orbread fruit at 7 m distance between rows and 6 m between plantswould be economical (Fig. 21). These crops require light irrigationand are not suitable for dry areas.

3. Between two rows of cashew the spacing maintained is 10 m. In themiddle, planting acacia or casuarinas along with wild mango to theborders at 12 m distance would give ecological sustainability(Fig. 22). Acacia and casuarina should be regularly pruned after 2-3years and leaves may be incorporated into cashew basins. After 5-6years these trees are cut and sold. For planting along the borders

vision Fig. 20: Mixed cropping of cashew with mango/tamarind/cotton/jack fruitand sapota/ phyllanthus.

-some of the wild mango varieties could be selected and multipliedby softwood grafting and may fetch a better price in the domesticmarket itself when compared to the popular varieties.

4. The other combination would be cashew, dwarf bamboo and kokumas in Fig. 23. Bamboo is increasingly gaining importance due to its

vision Fig. 21: Mixed cropping of cashew with guava / longon andbread fruit/rambutan

vision Fig. 22: Mixed cropping of cashew with acacia, casuarina andwild mango

suitability for fabrication of inexpensive and beautiful furniture andhandicrafts. It also serves as a basic raw material to industry. Due toflowering, there is decline in bamboo crop over the years and abruptshortfall of supply may increase the price in the future . Kokum is afruit of various medicinal uses. The rind of the fruit, is used in makingjuices and beverages. The juice prepared from the rind has a naturalcooling effect on the body and is widely used in Maharastra and

Fig. 23: Mixed cropping of cashew with dwarf bamboo andgarcinia (kokum)

Karnataka. It contains the chemical-Hydroxy citric acid, which isknown to have an anti-obesity effect.The fat extracted from the kokumseeds has a special property of melting at higher temperature. Henceit can be blended with cocoa, milk and sugar so that the chocolatecan be kept stable at room temperature, unlike the chocolates prepared purely from cocoa butter. At NRCC, kokum is grown asmixed crop in cashew garden accommodating 200 plants in onehectare area. About 20-30 kg yield from single tree (400-600 kg perha) can be expected. The return from a kokum tree will be aboutRs. 100 to Rs.150 per tree and Rs. 20,000 to Rs. 30,000 per ha.The cost of cultivation is Rs. 30 per plant (Rs. 6,000 per ha.) and netprofit will be Rs. 70 to Rs. 120 per plant or Rs. 14,000 to Rs. 24,000per ha.

14. Estimating the number of plants per unit area
With a simple calculation one can estimate the number of cashewplants and other inter or mixed crops to be planted in a unit area. Onehectare is equal to 10,000 square meters. When this figure is dividedby the area covered by each plant as per the spacing provided, thetotal number of plants accommodated can be determined as detailedbelow. Lay-out explained in Fig. 21 is taken as example.


15. Bee keeping
The yield of cashew may be enhanced to a little extent through beekeeping since cashew is a highly cross pollinated crop. Honey beesassist in the process of pollination. Intercropping or mixed croppingwith other tree crops would definitely meet the nutritional requirementsof the colony. Honey will be an additional source of income.

16. Irrigation and drainage
Cashew is grown under rainfed conditions. However, it is preferableto give supplementary irrigation during summer months, especiallyduring January-March at fortnightly intervals at the rate of 200 litres perplant which has proved to double the yield. This is evident from theresearch results obtained at NRCC. The frequency and quantity of irrigation water varies. Cashew responds well to drip irrigation at therate of 60-80 litres of water per tree once in four days after the initiationof flower panicles till fruit setting and development (January-March).Cashew cannot withstand water stagnation. In high rainfall areasplantations located in low lying areas should have trenches to drain outexcess water.

17. Weed managementGenerally weeding in cashew can be done twice a year. Oneweeding in the month of August before manure application and another,just before the start of flushing and flowering (October or November).The weed biomass can be effectively recycled as mulch cum greenmanure by applying around the plant basin.

18. Plant protectionIn India about 60 insect pest species are identified on cashew.Major pests are Tea Mosquito Bug (TMB), Cashew Stem and RootBorer (CSRB), Leaf Miner, Leaf and Blossom Webber and Flower Thripsas well as CashewApple and Nut borer. So far there are no major fungalor viral diseases causing economic loss in cashew

18.1. Management of Tea Mosquito Bug (TMB) -

Helopeltis antonii Sign. (Heteroptera ; Miridae)
Tea mosquito bug can cause yield reduction to the tune of 30-40per cent by damaging tender shoots, inflorescences and nuts. Bothadults and nymphs (Fig 24 and 25) of TMB suck the sap from tendershoots, panicles, immature nuts and apples resulting in the formationof black lesions. These lesions on shoots and panicles coalesce causingshoot blight or blossom blight (Fig. 26). The plants can escape TMBattack if the new flush is delayed. Planting mid season or late seasonflowering varieties would be the right strategy to escape TMB. Evenearly flowering varieties also flower 10-15 days late if the plants aregrown organically compared to chemical fertilizer applied ones. Thedelay in flowering naturally minimizes the incidence by escapingmultiplication of TMB population. The pest could be repelled by smokingthe garden by burning organic residues three times during flushing,flowering and fruiting. Care must be taken to see that small heaps oforganic wastes in several places on the ground below the canopy of thetree is burnt slowly. This can be achieved by putting a thin layer of soilon the heaps and setting fire. At any chance the burning should notproduce too much of heat lest flowers and shoots get affected. Clean

vision Fig. 24: An adult TMB

vision Fig. 25: TMB nymph

vision Fig. 26: TMB damage in cashew

cultivation is another method to check multiplication of TMB considerably.All weeds should be removed and heaped as mulch. Encouragingmultiplication of weaver ants (Oecoyphylla smaragdina) checks thespread of TMB (Fig. 27) by feeding on its eggs and nymphs. In theinitial stages the colonies of weaver ants may be brought from near byforest.

At NRCC Puttur, a plot of 2.5 hectares is maintained for the lastfour years and though initially the TMB damage was noticed in smallpockets, no economic loss on yield was observed. Here the organicinsecticides like Servo-agro-spray oil (Petroleum by-product), PhaladaIII C1 and Phytozeal were sprayed during flushing, flowering and fruitingperiods. Foliar spray of Phalada phytozeal was found effective. Thougha little damage was noticed due to TMB initially in certain mid varieties(V-4), it did not spread later indicating that the pest can be broughtunder check with these organic pesticides.

18.2. Management of Cashew Stem and Root Borer (CSRB)
Plocaederus ferrugineus L. (Coleoptera; cerambycidae)
Older cashew trees are more prone to infestation by CSRB(Fig. 28). Adult female beetles (Fig. 29) lay eggs in the bark crevicesof the stem (near the collar region) or on the exposed roots. After

vision Fig. 27: Weaver ants - natural enemy for TMB

hatching, the young grubs (Fig. 30-a) tunnel immediately into the barkof the trunk or root regions. Due to their extensive feeding by irregulartunneling in the bark, the translocation of the nutrients is hamperedleading to drying of leaves and twigs. In the infested portions the gumand frass (chewed fibres and excreta pellets) start oozing out from thetree which is the initial symptom of pest attack. Curative measuresgiven below should be taken up immediately.

The infested portion, having frass below the bark on either the mainstem or root portion (up to a depth of 2 ft) should be carefully chiselledto inflict minimum damage to the bark. Tunnels should be tracked (Fig.32) towards the fresher frass to locate the CSRB grubs, which shouldthen be removed and killed. In case white powdery fibres are seen itindicates that the grubs have entered the heart wood for pupation. Insuch cases a pliable wire (for example automobile gear wire ) should beinserted deep into the pupation hole and pushed in till a slushy soundis heard or milky white fluid flows out indicating damage to the grub or

vision Fig. 28: CSRB infested cashew tree

vision Fig. 29: CSRB adults vision Fig. 30: CSRB just emerged gruband egg

vision Fig. 30-a: CSRB grubs vision Fig. 31: CSRB pupa

pupa. Later chiselled portion of the bark should be swabbed with 10 percent bordeaux paste. When a paste of cow dung and ash is applied tothe injured portion of the bark, it helps in curing of wounds. Swabbingneem oil is also quite effective.

Trees having more than 50 per cent of the bark circumferencedamaged by the insect or with yellowing of the canopy hardly everrecover. In addition, the pest stages in such trees will act as inoculumfor the next season. Hence phyto-sanitation should be adopted byuprooting such trees which are beyond recovery and disposed offimmediately, along with removal of pest stages in other infested trees.Such operations prevent build up of pest inoculum.As the pest incidenceoccurs during the period of nut collection (Feb-May), the infested treescan be marked and curative measures could be adopted immediately,so that the grubs do not inflict more damage. As a preventive measure,brushing waste motor oil or clay soil once or twice a year to the lowertrunk region discourages egg laying (Fig. 32).

Minor pests like Cashew Apple and Nut Borer (Fig. 33 and 34), leafminer, leaf and blossom webber can be mechanically controlled atyounger stages of plant growth or with organic sprays suggested forTMB. As the plant grows older the loss is insignificant.
vision Fig. 32: CSRB grubs being removed from the infested trunk of a cashew treeInset : Hand axe, cable and waste motor oil.

vision Fig. 33: Cashew nut damaged by cashew apple and nut borer

vision Fig. 34: Cashew apple damaged by cashew apple and nut borer