Pest and disease management in coconut cultivation

A. Pest management

Pests	Management strategies
Rhinoceros beetle Oryctes rhinoceros	Remove and burn all dead coconut trees in the garden (which are likely to serve as breeding ground) to maintain good sanitation. Collect and destroy the various bio-stages of the beetle from the manure pits (breeding ground of the pest) whenever manure is lifted from the pits. Incorporate the entomopathogen i.e, fungus (Metarrhizium anisopliae) in manure pits to check the perpetuation of the pest. Soak castor cake at 1 kg in 5 l of water in small mud pots and keep them in the coconut gardens to attract and kill the adults. Treat the longitudinally split tender coconut stem and green petiole of fronds with fresh toddy and keep them in the garden to attract and trap the beetles. Examine the crowns of tree at every harvest and hook out and kill the adults. For seedlings, apply 3 naphthalene balls/palm weighing 3.5 g each at the base of inter space in leaf sheath in the 3 inner most leaves of the crown once in 45 days. Set up light traps following the first rains in summer and monsoon period to attract and kill the adult beetles. Field release of Baculovirus inoculated adult rhinoceros beetle @ 15/ha reduces the leaf and crown damage caused by this beetle. Apply mixture of either neem seed powder + sand (1:2) @150 g/palm or neem seed kernel powder + sand (1:2) @150 g per palm in the base of the 3 inner most leaves in the crown Set up Rhinolure pheromone trap @ 1/ 2 ha to trap and kill the beetles.
Black headed caterpillar Opisina arenosella	The incidence of the pest is noticed from the month of November to May and from August to November after rainfall. The coconut trees of all ages are attacked. Release the larval (Bethylid, Braconid and Ichneumonid) and pupal (Eulophid) parasitoids and predators periodically from January, to check the build up of the pest during summer. Among the larval parasitoids, the bethylid Goniozus nephantidis is the most effective in controlling the pest. The optimum level of release is 1:8 of host-parasitoid ratio. The parasitoid should be released @3000/ha under the coconut trees when the pest is in the 2nd or 3rd instar larval stage. Parasitoids should not be released in the crown region since they will be killed by predators like spiders and reduviid bugs. Remove and burn all affected leaves/leaflets. Spray Malathion 50 EC 0.05% (1mi/lit) to cover the undersurface of the leaves thoroughly in case of severe epidemic outbreak of the pest in young palms. Root feeding for the control of coconut Black headed caterpillar: Select a fresh and live root, cut sharply at an angle and insert the root in the insecticidal solution containing Monocrotophos 36 WSC 10 ml + water 10 ml in a 7 x 10 cm polythene bag. Secure the bag tightly to the root with a cotton thread. Twenty four hours later, check whether there is absorption. If there is no absorption select another root. These methods should not be resorted to as a routine practice and it is suggested only for cases of severe epidemic outbreak of the pest and when the survival of the tree is threatened.
Red palm weevil Rhynchophorus ferrugineus	Remove and burn all wilting or damaged palms in coconut gardens to prevent further perpetuation of the pest. Avoid injuries on stems of palms as the wounds may serve as oviposition sites for the weevil. Fill all holes in the stem with cement. Avoid the cutting of green leaves. If needed, they should be cut about 120 cm away from the stem. Plug all holes and inject Pyrocone E or Carbaryl 1% or 10 ml of Monocrotophos into the stem by drilling a hole above the points of attack. Setting up of attractant traps (mud pots) containing sugarcane molasses 2½ kg or toddy 2½ litres + acetic acid 5 ml + yeast 5 g + longitudinally split tender coconut stem/logs of green petiole of leaves of 30 numbers in one acre to trap adult red palm weevils in large numbers. Root feeding: As under black headed caterpillar
Termites Odontotermes obesus	Locate termite mounds in or near the coconut nursery or garden and destroy. Swabbing with neem oil 5% once on the base and upto 2 m height of the trunk for effective control. Spray Copper sulphate 1 % or Cashew nut shell oil 80 % followed by Copper sulphate 1 % then neem oil 5 % and copper sulphate 1 %, then NSKE 20 % to preserve planted coconut leaves from the termite attack.
Scale insect Aspidiotus destructor	Pluck mature nuts and spray Monocrotophos 36 WSC 1 ml/ha. Do not harvest nuts for 45 days after spraying.
Mealy bugs Pseudococcus longispinus	Remove leaflets harbouring these insects and destroy them Spray any one of the following : Malathion 50 EC 2 ml/lit (or) Dimethoate 30 EC 1 ml/lit (or) Methyl demeton 25 EC 1 ml/lit (or) Phosphamidon 40 SL 1.25 ml/lit (or) Monocrotophos 36 WSC 1 ml/lit (or) Methomyl 25 EC 1 ml/lit (or) Neem oil 3% (or)
Leaf caterpillars Turnaca acuta	Collect and destroy the immature stages of the insects wherever possible and spray Carbaryl 0.1 %. A combined treatment of root feeding of Monocrotophos at 5 ml + 5 ml water, spraying of 0.01% Monocrotophos followed by the release of Parasitoids at every 15 days interval of time effectively control leaf eating caterpillars.
Nut caterpillar
Nut coreid bug
Slug caterpillar Contheyla rotunda	Spray any one of the following: Dichorvos 76 WSC 2 ml/lit Bacillus thuringiensis 2 g/lit, Triazophos 40 EC 5 ml Methyl demeton 25 EC 4 ml/lit Root feeding with monocrotophos 15 ml + 15 ml of water
Scolytid bark borer beetles Xyleborus parvulus	Stem injection through a stove wick soaked in 0.2% fenthion or 0.2% dichlorvos and plugging the hole and repeating the treatment using the same wick and hole a month after.
Palm civet Vivera zibatha	Poison baiting with ripe banana fruit sandwiched with 0.5 g carbofuran 3 G granules.
Rat Rattus rattus wroughtoni	Tree banding with inverted iron cones or Prosophis thorns. Baiting with bromodialone 0.005% at 10 g/tree at crown region twice at an interval of 12 days.

Special problem: Coconut eriophyid mite (Aceria guerreronis)

Package of recommendations for the management of the coconut eriophyid mite

Coconut eriophyid mite

Manurial and fertilizer recommendation (Soil application/tree/year)

Urea 1.3 kg
Super phosphate 2.0 kg
Muriate of potash* 3.5 kg
* Increased quantity is recommended to increase the plant resistance to the mite.
Neem cake application @ 5 kg
Organic manure (well rotten FYM) @ 50 kg

Micronutrients (Soil application / tree / year)

Borax 50 g
Gypsum 1.0 kg
Magnesium sulphate 500g
Grow sunnhemp as intercrop twice a year (Seed rate 30 kg/ha)

Spot application of ecofriendly Botanicals

Round	Eco-friendly Botanical	Quantity / tree
1.	Azadirachtin 1%	5 ml in one lit. of water
2.	Neem oil + Teepol	30 ml in one lit. of water
3.	Azadirachtin 1%	5 ml in one lit. of water

Method of application

The botanicals should be applied in the sequence indicated above at 45 days interval using a one litre hand sprayer. Rocker or Pedal sprayer can be used for spraying small trees.
The spray should be applied at the crown region by a climber covering only the top six bunches during non rainy season.
The bunches must be covered well by the spray fluid and approximately one litre of spray fluid may be required per tree

Precautions and safety measures

Spraying should be avoided during windy season to prevent contamination.
At the time of spraying, protective mask and clothing should be used.
Wash face and hands cleanly with soap after spraying.

B. Disease management

I. Basal stem rot - Ganoderma lucidum
Cultural Method

Apply Pseudomonas fluorescens (Pf1) @ 200 g/palm + Trichoderma viride @ 200 g/palm/year
Apply 200g phosphobacteria and 200 g Azotobactor mixed with 50 Kg of FYM/palm
Green manure crops must be raised and ploughed in situ
Neem cake 5 kg/tree must be applied along with fertilizers

Chemical

Aureofungin-sol 2 g + 1 g Copper sulphate in 100 ml water or 2 ml of Tridemorph in 100 ml water applied as root feeding. (The active absorbing root of pencil thickness must be selected and a slanting cut is made. The solution to be taken in a polythene bag or bottle and the cut end of the root should be dipped in the solution).

Forty litres of 1% Bordeaux mixture should be applied as soil drench around the trunk in a radius of 1.5 metre.

II. Bud rot - Phytophthora palmivora
The infective tissues from the crown region should be removed and protected with Bordeaux paste. Spray Bordeaux mixture at 1% or Copper oxy chloride 0.25 % on crown region as pre-monsoon spray. Spray Copper oxy chloride 0.25 % after the onset of monsoon.
III. Stem bleeding disease
The bark of the trunk should be removed in the bleeding area and Bordeaux paste should be applied in this area.
IV. Pencil point disease
Because of micronutrient deficiency, the stem will taper towards its tip with lesser number of leaves. The leaf size will be greatly reduced and the leaves will be pale and yellow in colour. Along with the recommended fertilizer dose, 225 g each of Borax, Zinc sulphate, Manganese sulphate, Ferrous sulphate, Copper sulphate and 10 g of Ammonium molybdate may be dissolved in 10 1 of water and poured in the basin of 1.5 m radius.

a. Preparation of 1% Bordeaux mixture

A quantity of 400 g of copper sulphate should be dissolved in 20 litres of water and 400 g of lime in another 20 litres of water separately. The copper sulphate solution should be added to the lime solution constantly stirring the mixture. Earthen or wooden vessels alone should be used and metallic containers should not be used. To find out whether the mixture is in correct proportion, a polished knife should be dipped in the mixture for one minute and taken out. If there is reddish brown deposit of copper, additional quantity of lime should be added till there is no deposit in the knife.

b. Preparation of Bordeaux paste
Take 200 g of Copper sulphate and dissolve it in one litre of water and 200 g of lime in one litre of water separately. Both are mixed simultaneously in a third vessel and the resultant mixture can be used as a paste.

Harvest and post harvest technology
Harvest 11-12 months old fully matured nuts at an interval of 30-45 days depending on the yield level of the garden. For household use keep the nuts in vertical direction. Dry copra either by sun drying or by using copra dryers. Store the copra at 5-6 % moisture content. Store the copra in polythene tar coated gunny bags.

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Pests

The insect pests of the coconut palm are

Rhinoceros Beetle - Oryctes rhinoceros

Red Palm Weevil - Rhynchophorus ferrugineus

Black Headed Caterpillar - Opisina arenosella

Slug Caterpillar - Parasa lepida and Contheyla rotunda

Coconut Skipper - Gangara thyrsis and Suastus gremius

Coreid Bug - Paradasynus rostratus

Bag Worm - Manatha albipes

Lacewing Bug - Stephanitis typicus

Scale Insect - Aspidiotus destructor

Rats - Rattus rattus wroughtoni

Palm Civet - Vivera zibatha

Mealy Bugs - Pseudococcus longispinus

Termites - Odontotermes obesus

White Grub - Leucopholis coneophora

Eriophid Mite - Aceria guerreronis

Nut Borer - Cyclodes omma

Nematodes

Diseases

The diseases of the coconut palm are

Bud Rot - Phytophthora palmivora

Leaf Rot - Bipolaris halodes

Stem Bleeding - Ceratocystis paradoxa and Chalara paradoxa

Root (Wilt) Disease - Unknown Etiology

Thanjavur Wilt - Ganoderma lucidum

Mahali - Phytophthora palmivora

Crown Chocking

Leaf Blight or Grey Leaf Spot - Pestalosia palmivora

Lethal leaf blight - Lasiodiplodia theobromae

Tatipaka Disease - Phytoplasma

Botryodiplodia Nut Fall - Botryodiplodia theobromae

Inflorescence Blight and Nut Fall - Colletotrichum gloeosporioides, Gloeosporium spp

Mid Whorl Yellowing / Quick Yellow Declining - Phytoplasma

SPECIAL PROBLEMS IN COCONUT
1. Rejuvenation of existing garden
The low yield in vast majority of gardens is due to thick population, lack of manuring and irrigation. These gardens could be improved if the following measures are taken.

Thinning of thickly populated gardens: In the farmer’s holdings where thick planting is adopted, many trees give an yield of less than 20 nuts/palm/year. By cutting and removal of these trees, the yield could be increased. Besides, there is saving in the cost of cultivation and increase in net profit. After removal of low yielding trees, the populations should be maintained at 175 palms/ha.

Ensuring adequate manuring and irrigation: The yield can be increased in the existing gardens when manuring + irrigation + cultural practice is adopted as per recommendation.

2. Pencil point disorder (Micronutrient deficiency)
Because of micronutrient deficiency, the stem will taper towards its tip with lesser number of leaves. The leaf size will be greatly reduced and the leaves will be pale and yellow in colour. Along with the recommended fertilizer dose, 225 g each of Borax, Zinc sulphate, Manganese sulphate, Ferrous sulphate, Copper sulphate and 10 g of Ammonium molybdate may be dissolved in 10 litres of water and poured in the basin of 1.8 m radius. This disorder can be corrected if noticed early. Severely affected palms may be removed and replanted with new seedlings.

3. Button shedding

Button shedding

Shedding of buttons and premature nuts may be observed to many reasons: Provide regular irrigation, requested nutrition to reduce the button shedding.

Barren nuts
Apply extra 2 kg of K2O with 200 g of Borax/palm over and above the usual dosage of fertilizer to correct the barren nuts in coconut.

Regularly survey for pest and diseases
Select seedlings 9 to 12 months after planting. Seedlings, which have germinated earlier, having good girth at collar and early splitting of leaflets, should be selected for planting.

TNAU MN mixture @ 1 kg/tree/year
(*Enriched FYM prepared at 1:10 ratio of the MN mixture and FYM, mixed at friable moisture and incubated for one month in shade).

Physiological Disorders

Deficiencies for nutrients such as nitrogen, phosphorus, potassium and micronutrients are very common in coconut cultivation. Symptoms are often observed in coconut gardens where the trees are not properly fertilized especially with organic manures.

Major Nutrients

1. Nitrogen (N) Deficiency
Symptoms
N deficiency is typically caused by insufficient N in the soil. Nitrogen deficiency begins as a uniform light green discoloration / yellowing (uniform chlorosis) of the oldest leaves. Yellowing starts from tip to base of the lower leaves and will proceed up. As the deficiency progresses, younger leaves will also become discoloured. Older leaves are golden yellow colour. Growth virtually stops when N deficiency is severe and become shedding of leaves.
Diagnostic Techniques
Nitrogen deficiency is easily diagnosed by symptoms alone, although leaf nutrient analysis can also be helpful. Nitrogen deficiency can be confused with Fe or S deficiency, although the chlorosis in those deficiencies is typically most severe on the youngest leaves. The reverse is true for N deficiency.
Management
Foliar application of 2% urea thrice at fortnightly interval or soil application of 1-2 kg urea / tree or root feeding of 1% urea (1 g/litre of water) 200 ml twice a year.

Deficiency Symptoms

Uniform Chlorosis

Yellowing Starts from Tip to Base

Yellowing of Leaves

2. Potassium (K) Deficiency
Symptoms

Symptoms first appear on oldest leaves and later spread to young leaves.
Translucent yellow or orange spots develop on leaflets (Yellowing of leaf margin).
Older leaves are showing necrotic spotting as well curling of leaflet tips.
Leaflets with necrotic areas along the margins which later wither
The tree appears yellow and nicky, the trunk in slender with few short leaves.

Diagnostic Techniques
Visual symptoms alone may be sufficient for diagnosis of this disorder although leaf nutrient analysis may be helpful in distinguishing late stage K deficiency from manganese (Mn) deficiency. These two deficiencies can be extremely similar from a distance, but close examination should reveal characteristic spotting and marginal necrosis in K deficiency or necrotic streaking for Mn deficiency. Potassium deficiency symptoms are also more severe toward the leaf tip and are less so at the leaf base. The reverse is true for Mn deficiency.
Management

Regular applications of K fertilizers will prevent K deficiency and treat palms already deficient. On sandy soils, or those having little cation exchange capacity, controlled-release K sources are much more effective than the easily leached water-soluble K sources.
Application of resin coated K2SO4 @ 3 - 4 kg/tree, four times a year along with 2 kg MgSO4 / tree.
Root feeding of 200ml of 1% KCL per tree thrice a year.

Deficiency Symptoms

Leaf Declaration and Extensive Necrosis of Leaflet Margins and Tips

Leaflets Tip Necrosis and Curling

Small Chlorotic and Necrotic New Leaves and Trunk Tapering

Translucent Yellow Orange Spotting

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3. Phosphorus Deficiency
Symptoms

Purple coloration in leaves (In severe cases may leaves turn yellow before drying prematurely)
Sluggish growth
Leaves stay upright
Premature leaf shedding

The growth, leaf size and leaf number reduced. The root growth is restricted if phosphorus deficiency is recorded. There are no clear visual symptoms of phosphorus deficiency other than stunting and decrease in yield.
Management
Foliar spray of DAP 2% twice at fortnightly interval or soil application of FYM 5kg/tree. Root feeding of 1% DAP 2 ml twice a year.

Deficiency Symptoms

Yellowing and drying of leaves

4. Sulphur Deficiency
Symptoms
Typical symptoms are yellowish-green or yellowish-orange leaflets. Old leaves remain green. Leaves droop as the stem becomes weak. In older palms, leaf number and size are reduced. Sometimes an apron of dead fronds develops around the stem due to weakness of the rachis. Nuts may fall prematurely. Copra is rubbery and of poor market quality.
Management
Soil application of gypsum 2 - 5 kg/tree/year. Root feeding of 0.2% (2g/litre of water) gypsum.

Deficiency Symptoms

Apron of Dead Fronds Develops Around the Stem due to Weakness of the Rachis

Leaf Number and Size Reduced

Minor Nutrients

1.Boron (B) Deficiency
Symptoms

Symptoms always occur on newly emerging leaves, and remain visible on these leaves as they mature and are replaced by younger leaves.
One of the earliest symptoms of B deficiency on coconut palm is leaf wrinkling and manifested as sharply bent leaflet tips, commonly called “hook leaf”. Leaves have a serrated zigzag appearance.
Other common symptom is the failure of newly emerging spear leaves to open normally. In a chronic stage, multiple unopened spear leaves may be visible at the apex of the canopy.
Boron deficiency also occurs in inflorescence and nuts. The inflorescence and nuts are become necrotic.

Diagnostic Techniques
Boron deficiency symptoms are quite distinctive and are usually sufficient for diagnosis by themselves. Manganese deficiency produces symptoms similar to those of B deficiency, but no other common deficiency produces symptoms that could be confused with those of B deficiency. Because B deficiency is so transient in nature, the element is immobile within the palm (cannot move from one leaf to another), and deficiencies affect only leaf primordial developing within the bud area, leaf analysis is not particularly useful.
Management
Foliar spray of 0.2 % (2g in 1 lire of water) borax at the rate of 75 – 100 ml per seedling. Spraying is commonly practiced when coconut palms are at the nursery stage. 1 year old – Borax 5-10 g/plant per year 2-3 years old – Borax 15- 20 g/plant per year 4 years old and more – Borax 30 -50 g/plant per 2 years

Leaf Fail to Open Properly

Leaf Wrinkling and Distortion

Necrotic Inflorescence

Severe Leaf Distortion

Boron deficiency symptoms

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2.Manganese (Mn) Deficiency
Symptoms
Manganese deficiency is very common on alkaline soils. The newest leaves of Mn deficient palms emerge chlorotic with longitudinal necrotic streaks. As the deficiency progresses, newly emerging leaflets appear necrotic and withered on all but basal portions of the leaflets. This withering results in a curling of the leaflets about the rachis giving the leaf a frizzled appearance (frizzle top). In severely Mn- deficient palms, growth stops and newly emerging leaves consist solely of necrotic petiole stubs.
Diagnostic Techniques
Visual symptoms may be sufficient to diagnose this disorder, but leaf nutrient analysis is also suggested, since symptoms of boron (B) deficiency can be similar. Late stage potassium (K) deficiency symptoms are virtually indistinguishable from those of Mn deficiency at a distance and close examination is required to look for characteristic longitudinal streaking and basal symptom distribution of Mn deficiency.
Management
Soil application of MnSO4 @ 25kg/ha



Manganese (Mn) deficiency symptoms

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3.Magnesium (Mg) Deficiency
Symptoms
Magnesium deficiency appears on the oldest leaves of palms as broad chlorotic (yellow) bands along the margins with the central portion of the leaves remaining distinctly green. In severe cases leaflet tips may become necrotic. Older leaves become bronzed and dry appearance. Leaflets show necrosis and turn to reddish brown with translucent spots yellowing starts at the tip and spreads to the base.
Diagnostic Techniques
Visual symptoms alone are usually sufficient to diagnose Mg deficiency. Magnesium deficiency symptoms differ from those of K deficiency in that symptom severity of discoloration K- deficient leaves is usually orange to bronze, shading gradually to green at the base of the leaf, whereas Mg- deficient leaves have distinctly green leaf centers and bright lemon yellow to orange margins.
Management
Soil application of MgSO4 1-2 kg/tree/year. Root feeding of 200 ml of 0.2% MgSO4 twice a year.


Magnesium (Mg) deficiency symptoms

4.Zinc (Zn) Deficiency
Symptoms
Zinc deficiency is characterized by formation of small leaves wherein the leaf size is reduced to 50%. Leaflets become chlorotic, narrow and reduced in length. In acute deficiency, flowering is delayed. Zinc deficiency will also lead to button shedding.
Management
Soil application of ZnSO4 @ 25kg/ha

Reduced Leaf Size

Small Nuts

Button Shedding

5. Iron (Fe) Deficiency
Symptoms

Iron deficiency usually appears on palms growing in poorly aerated soils or those that have been planted too deeply. Water logged soils and deep planting effectively suffocate the roots and reduce their effectiveness in taking up nutrients such as Fe.
The main symptom of iron deficiency is chlorosis or yellowing between the veins of new leaves (Uniform chlorotic new leaves as the deficiency progresses, the tips become necrotic and leaf size reduced).

Management
Application of Feso4 0.25 to 0.5 kg/tree/year