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COCONUT (Cocos nucifera).pptx
1. Maintenance of healthy coconut plantation
Rajib Kumar De
Principal Scientist
Crop Protection Division
ICAR-Central Research Institute for Jute and
Allied Fibres
Barrackpore, Kolkata 700 120 (WB)
2. COCONUT (Cocos nucifera)
The coconut tree is a member of
the family Arecaceae (palm family).
Coconut is found in the tropics and subtropics.
Coconut is unique for containing "water" for
drinking. It is a “superfood” with amazing
benefits.
Coconuts can be processed to oil from the
kernel, charcoal from the hard shell
and coir from the fibrous husk.
The cellular layers of endosperm deposit along
the walls of the coconut, to become flesh
or dried into copra for oil and milk.
The coconut palm thrives on sandy soils and is
highly tolerant of salinity. It prefers abundant
sunlight and regular rainfall (1500 to 2500 mm
annually), high humidity (70–80%+) and
mean temperature 28 - 37 °C for optimum
growth.
3. Coconut is cultivated in Kerala, Tamil Nadu,
Karnataka, Andhra Pradesh, Puducherry, Goa,
Maharashtra, Odisha, West Bengal and the
islands Lakshadweep and Andaman and Nicobar.
Four southern states account for 92% of total
production: Kerala (45%), Tamil Nadu (27%),
Karnataka (11%), and Andhra Pradesh (9%).
Kerala has largest number of coconut trees, is
famous for coconut-based products—coconut
water, copra, coconut oil, coconut cake, coconut
toddy, coconut shell-based products, coconut
wood-based products, coconut leaves, and coir
pith.
In Kerala, the coconut tree is termed as kalpa
vriksham, which essentially means all parts of
coconut tree is useful some way or other.
COCONUT IN INDIA
4. Maintenance of healthy coconut plantation
Planting materials : Good mother plants and healthy seedlings,
proportion of female flowers, high fruit setting, copra content,
Spacing: 7.5 – 9 m x to accommodate 177 – 124 plants /ha
Irrigation: 45 litres once in 4 days or 250 litres water / week with
good drainage. Inter-culture: Regular weeding, ploughing, intercropping, etc.
Follow integrated nutrient management
Grow green manure crops - cowpea, sunhemp (Crotalaria juncea),
Mimosa invisa, Calapagonium mucanoides, Pueraria phaseoloides,
etc. may be sown in coconut basins during April-May and
incorporated during September-October.
Apply organic or compost manure @ 50kg / palm / year.
Apply balanced dose of chemical fertilizers i.e. 500g Nitrogen (1.1kg
urea), 300 g Phosphorus (1.7 kg Mussouriphos), 1000g Potassium
(1.7 kg Muriate of potash) in two splits - 1/3rd during April-May and
2/3rd during September-October under rainfed condition and in four
splits during January, April, July and October under irrigated
condition and 1000:500:2000 per plant for hybrids making circular
basin of 1.8 -2 m radius.
In addition to this 500g MgO (1 kg Magnesium sulphate) also has to
be applied along with second dose of fertilizer application.
5. Follow strictly all the prescribed prophylactic measures
against leaf rot disease, red palm weevil, rhinoceros
beetle etc. so as to ensure that the palms are not
debilitated.
Practice clean cultivation and burn off diseased plant
parts;
Cleaning at regular interval;
Rouging of diseased and low yielding plants;
Root feeding with 3-5% Tridemorph (Calixin) or 3%
metalaxyl (Ridomil, Apron) may be adopted 3 times a
year for sick plants.
Cut and burn severely affected palms which cannot be
saved.
Harvesting: Starting at 5- 7 years to 50-60 years,
average yield 10000 -14000 and up to 25000 nuts per ha
per annum.
FIELD SANITATION IS MOST IMPORTANT
FOR HEALTHY COCONUT PLANTATION
7. Bacterial, virus and viroid, phytoplasmal diseases
miscellaneous disorders of coconut
Bacterial diseases
37 Bacterial bud rot Erwinia spp.
Virus and viroid diseases
25 Cadang-cadang Coconut cadang-cadang viroid
26 Foliar decay SS-DNA, identity uncertain
27 Tinangaja Coconut tinangaja viroid
28 Natuna wilt Not known
29 Premature decline Not known
30 Soccoro wilt Not known
Phytoplasmal diseases
38 Awka disease Phytoplasma
39 Blast
Phytoplasma
suspected
40 Cape St. Paul wilt Phytoplasma
41 Cedros wilt
Phytomonas
stahellii
42 Heart rot
Phytomonas
stahellii
43 Kaincope disease Phytoplasma
44 Kalimantan wilt
Phytoplasma
suspected
45 Kribi disease Phytoplasma
46 Lethal decline Phytoplasma
47 Lethal disease Phytoplasma
48 Lethal yellowing Phytoplasma
49 Pudricion del cogollo Phytoplasma
50 Root wilt disease Phytoplasma
51 Stem necrosis
Phytoplasma
suspected
Miscellaneous diseases and disorders
31 Bristle top Not known
32 Dry bud rot
Not known, but possibly vectored by
the insects Sogatella kolophon and S.
yubana
33 Finschafen disease Not known
34 Frond rot Physiological disorder
35 Leaf scorch decline Not known
36 Malaysia wilt Not known
8. ROOT (WILT) DISEASE
The most important disease of coconut in the State.
Non lethal but debilitating disease affecting palms of all ages.
Occurs in a contiguous manner in an area of 4.1 lakh ha in eight southern districts of the State,
stretching from Thiruvananthapuram in the South to Thrissur in the North.
The disease is not a fatal one but a slow decline disease causing drastic yield reduction.
Symptoms
Abnormal bending or ribbing of the leaflets, flaccidity of the leaves, general yellowing followed by
marginal necrosis of the leaflets.
Abnormal shedding of buttons, reduced leaves and crown, gradual reduction in yield. Symptoms
Flaccidity of leaves of the central and outer whorls is the earliest consistent symptom irrespective of the
age of the palm or the soil type
Whole frond develops a cup like appearance (Plate2)
Foliar yellowing and marginal necrosis of leaflets of the outer whorls of leaves (Plate3)
In seedling and juvenile palms, yellowing of foliage is not common and flaccidity is the only evident
symptom. Leaves produced subsequently become smaller and thinner
Paling of the younger leaves and stunting of the crown due to the reduction in number and size of the
leaves
Deterioration and decay of roots and rootlets from tip backwards and reduction in regeneration of fresh
roots
Root cortex turn brown and dries up in flakes
Superimposing of leaf rot disease on about 65% of the root (wilt) diseased palms contributes to the rapid
decline and reduction in yield of the affected palms (Plate4)
Drying up of the spathes and necrosis of spikelets from tip downward in unopened inflorescence (Plate
5)
Inflorescence necrosis, production of little or no female flowers, pollen sterility and shedding of
immature nuts and buttons
Reduction in size and number of nuts
Production of poor quality nut / copra, thinner husk, less firm shell, weaker fibres, uneven thickness of
kernel
Thinner kernel never dries up into copra but remains soft and flexible with very less oil content
Insipid tender coconut water Leaf bending
yellowing
marginal necrosis
reduced leaves
and crown
9. Causal Organism
• Mycoplasma Like Organism (MLO) Phytoplasma; Vectors – Lace wing bug – Stephanitis typicus
(Plate6); Plant hopper - Proutista moesta ; Occurs in all major soil types but the spread is faster in
sandy, sandy loam, alluvial and heavy textured soils. Laterite soils have lower incidence and intensity
of the disease.
• Higher incidence in water logged low lying areas adjacent to rivers and canals and also in neglected
gardens.
Management practices
• Being a non-lethal, debilitating disease an integrated approach is to be followed for management of
root wilt.
Efficient management of root (wilt) affected palms demand control of all pests and diseases, imparting
natural resistance and health to the palms through proper manuring and agronomic practices.
Recommended control measures for leaf rot disease as this disease gets superimposed on most of the
root wilt affected palms.
Cut and remove disease advanced, uneconomical palms yielding less than 10 nuts per palm per year.
Irrigate coconut palms with at least 250 litre water in a week. Provide adequate drainage facilities.
Adopt suitable inter/mixed cropping in coconut gardens.
• Desilt the channel and strengthen the bunds during summer months when the crop is grown under the
bund and channel system
• Adopt strictly all the prescribed prophylactic measures against leaf rot disease, red palm weevil,
rhinoceros beetle etc.
• Initial stage of the disease, spray the crown and drench the basin with 500 ppm tetracycline.
ROOT (WILT) DISEASE
10. FOLLOW INTEGRATED NUTRIENT
MANAGEMENT TO CHECK ROOT (WILT)
• Apply balanced dose of NPK fertilizers in the form of urea, rock phosphate and potash
• Average management : 0.34 kg N, 0.17 kg P2O5 and 0.68 kg K2O per palm per year
• Good management : 0.50 kg N, 0.32 kg P2O5 and 1.20 kg K2O per palm per year
• Add organic manures (cattle or green manure) @ 50 kg per palm per year
• Lime : 1 kg per palm per year and MgO (Magnesite Magnesium source) : 100g (In
Onattukara region: 500g)
• Grow green manure crops like sunhemp, sesbania, cowpea, calapagonium etc in the
coconut basin and incorporate in situ
• Adopt mixed farming by raising fodder crops in the interspaces and maintaining milch
cows
• Mixed cropping with cocoa and intercropping with tapioca, yams and elephant foot
yam
• Under rainfed conditions apply fertilizers in 2 splits, 1/3 at the time of south-west
monsoon and 2/3rd before the north-east monsoon. Under irrigated conditions apply
fertilizers in three equal splits during April-May, August-September and December-
January
• Apply fertilizers and manures in 10 cm deep circular basins at a radius of 2m from the
bole of the palm
11. Bud Rot/ Fruit Rot of Coconut
Symptoms
The earlier symptom is the yellowing of one or two
younger leaves. Black spots appear on spindle leaves.
In the later stages the spindle withers and drops
down.
The tender leaf base and soft tissues of the crown rot
into a slimy mass of decayed material emitting foul
smell.
Ultimately the entire crown falls down and the palm
dies
Management practices
Remove all affected tissue of the crown and apply
Bordeaux paste on cut end and provide a protective
covering till normal shoot emerges.
Spray 1% Bordeaux mixture on the crown of the
neighbouring palms as a prophylatic measure.
Spray with 1% Bordeaux mixture during May and
September if the disease occur frequently.
Cut and burn severely affected palms which cannot be
saved.
12. Bud Rot/ Fruit Rot of Coconut
Symptoms
•Common killer / fatal disease in mid and uplands of the State
•Affects palms of all ages, but young palms of less than 20 years of age are more
susceptible especially during rainy / monsoon season
•Characterized by rotting of the terminal bud and surrounding tissues which emit
foul smell (Plate13)
•Water soaked lesions at the base of the petioles of the young leaves in the
seedlings
•The spear leaf turns pale and comes off with a gentle pull in the seedlings
(Plate14)
•In adult palm, the first externally visible symptom is withering of the spear leaf,
which subsequently turns pale in colour, bends over at the base and hangs down
•Withering and yellowing of one or two younger leaves surrounding the spindle
•Rotting of the tender leaf base and soft tissues of the crown into a shiny mass of
decayed material that emit a foul smell which attracts flies (Plate15)
•Rotting progresses downwards, affects the meristem and kills the palms
•The internal tissues show discolouration assuming a pale pink with a brown
border (Plate16)
•Drooping of successive leaves and falling of leaves one by one, leaving only
mature leaves in the lower whorls at the crown (Plate17)
•Retained nuts on the palm grow to maturity
•The palm ultimately succumbs to the disease, if not checked
Causal Organism
Phytophthora palmivora and Phytophthora katsurae
13. Management of Bud Rot/ Fruit Rot of Coconut
1. In early stages of the disease, when the spindle leaf starts withering, cut and remove all affected
tissues of the crown along with some healthy tissues and apply Bordeaux paste and protect it
from rain by providing a mud pot or a polythene covering till normal shoots emerges (Plate18)
2. Spray 1% Bordeaux mixture to the spindle leaves and 2-3 innermost whorls of leaves
3. Burn all diseased tissues removed from the palm
4. As a prophylactic measure, spray 1% Bordeaux mixture on the spindle leaves and on the base of
3-4 innermost whorls of leaves of neighbouring palms
5. In palms that are sensitive to copper containing fungicides, spray and spray drench with
Mancozeb 0.4% (4g/L)
6. Small perforated sachets containing 2g Mancozeb may be tied to the top of the leaf axil. When it
rains, a small quantity of the fungicide is released from the sachets to the leaf base, thus
protecting the palm
7. Adopt control measures for rhinoceros beetle and red palm weevil
8. Provide adequate drainage in gardens
9. Adopt proper spacing and avoid overcrowding in bud rot prone gardens
10. In bud rot prone gardens, prophylactic measures should be done to all palms 2-3 times at 45
days intervals
11. Clean the crown before monsoon and follow strict phytosanitation
12. Regular application of organic matters favours the establishment of biocontrol agents and
suppression of pathogens
13. Apply salt and ash mixture or paddy husk after removing the affected portion in the crown and
subsequently cover with a mud pot. They absorb moisture and keep the protected portion dry
14. Apply bleaching powder on the affected portion
15. Cut and remove badly affected palms from the field
14. Management of Bud Rot/ Fruit Rot of Coconut
Spraying of
– metalaxyl (e.g., Tagron 35 WS) at
the rate of 0.2 % (i.e., 2 gm per
litre of water) or
– metalaxyl + mancozeb (e.g.,
Krilaxyl ML 72 WP) at the rate
of 0.2 % (i.e., 2 gm per litre of
water) or
– copper oxychloride (e.g., Blitox
50 WP, Fytolan 50 WP, Blue
Copper 50 WP) at the rate of 0.5
% (i.e., 5 gm per litre of water)
– mancozeb (e.g., Indofil M 45,
Dithane M 45) at the rate of 0.5
% (i.e., 5 gm per litre of water)
may check the disease to a great
extent.
Bordeaux paste
Dissolve 100 gm of copper sulphate (CuSO4)
in 500 ml water.
Dissolve 100 gm of quick lime (Ca(OH)2) in
500 ml water separately.
Mix two solutions to form 1 litre of
Bordeaux paste
Repeat spray at 20 – 30 day interval till problems persists.
FOUR NEW SYSTEMIC FUNGICIDES
(1) phenylamide (MEFENOXAM Ridomil
Gold SL), (2) phosphonate (FOSETYL-AL
Aliette), (3) cinnamic acid (Dimethomorph),
and (4) quinone outside inhibitor (QoI)
(azoxystrobin, kresoxim-methyl) groups .
They move into and within the plant and are
used to manage Phytophthora diseases.
15. Symptoms
Shedding of female flowers and immature nuts.
Lesions appear on the young fruits or buttons near
stalk which later result in decay of the underlying
tissues.
Female flowers and immature nuts rot and shed
especially during rainy season
Nuts of 2-5 months old are highly susceptible
Water soaked dark green lesions appear, usually near
the fruit stalk of immature nuts, which later turn
brown and become irregular in shape (Plate19)
Lesions spread on the husk and endosperm resulting
in their discolouration and rotting
Nuts fall prematurely (Plate20)
Fluffy white mycelial growth forms on the fallen nuts
or buttons (Plate21, 22)
Water soaked lesions on the inflorescence and rachis
result in rotting and drying of inflorescence and
rachis
Mahali / Fruit Rot / Nut Fall of Coconut
Fluffy white mycelial
growth
brown lesions with
discolouration and
rotting
16. Causal Organism
Phytophthora palmivora and Phytophthora katsurae
Spread of Disease
The fungus survives as oospores, chlamydospores and mycelium in the soil,
frond base or basal part of the crown. Heavy rainfall, high relative
humidity of 94-100% and temperature below 24oC are highly favourable
for the disease spread. Dissemination of the disease is primarily by wind
and wind blown rain and also by contact between bunches, dripping of
rain water from the diseased to healthy bunches and also through insects
Management practices
Remove and destroy fallen nuts.
In dwarf palms, apply Dithane M-45 in place of Bordeaux mixture.
Spray 1% Bordeaux mixture or copper oxychloride (5g/L) on the
bunches and crown during monsoon and subsequently twice at 40 days
interval along with stickers as prophylatic measure in disease prone
area
Collect and destroy the fallen nuts
In disease prone areas, adopt proper spacing of palms
Provide proper drainage
Regular manuring and proper cultural practices reduce the disease
incidence
Mahali / Fruit Rot / Nut Fall of Coconut
Nuts fall prematurely
17. Leaf Rot of Coconut
Symptoms
Blackening and shriveling up of distal ends of the leaflets in the
central spindle and younger leaves which later break off in bits.
Gradual weakening of the tree resulting in decline yield.
Affects palms of all ages, especially palms below 25 years
Water soaked lesions with different shape and colours on the
emerging spindle and young tender leaves (Plate7). Dark brown
spots develop on the tender leaves which later enlarge and dry up
as the leaf emerges (Plate8) and leaflets will not open fully
(Plate9). Successive central shoots are affected, resulting in rotting
of all the leaves on the crown. These lesions enlarge, coalesce
leading to extensive rotting of spindle leaves (Plate10). Extension
of rotting into the interior of spindle resulting in decay and
sometime rotting of buds
Tips of leaflets and midribs often become blackish, shriveled and
fall off in wind, giving a ‘fan’ like or ‘arrow leaf’ appearance to
the leaves (Plate11)
Successive infection of the emerging spindles results in
appearance of symptoms in most of the leaves of the crown
Extensive lesions and their coalescing results in severe blighting
of lamina (Plate12)
Breaking of ends of leaves which subsequently become yellow and
eventually hang, dry and fall of
Tips of leaflets and midribs
become blackish, shriveled
and fall off
Dark brown spots
18. Causal Organism
Fungal complex initiated predominantly by Colletotrichum gloeosporioides,
Exserohilum rostratum and Fusarium spp.
Spread of Disease
Primary spread through air-borne conidia. Free water, raindrops, high relative humidity
and low temperature especially during monsoon season are highly favaourable.
Management practices
Improve general condition of palms through proper manuring and management.
Remove and destroy severely affected / senile and uneconomic decayed portions
of spindle leaf and upmost two leaves only.
Pour fungicide solution of Hexaconazol (Contaf 5E) - 2ml or Mancozeb (Dithane
M45/ Indifil M45) - 3g in 300ml water per palm to the base of spindle leaf.
Apply 20g Phorate 10G mixed with 200g fine sand around the base of spindle
leaf.
2-3 rounds of spraying is sufficient in case of mild infection.
Clean the crown in general during pre-monsoon period.
Remove and destroy the rotten portions from the spear leaf and the 2-3
adjacent leaves
Pour 300 -1000 ml of fungicidal solution of 3g mancozeb in 300ml water at the
base of spear
Spray crowns and leaves with 1% Bordeaux mixture or 0.5% Copper
oxychloride formulation (5g/L) or 0.4% Mancozeb (4g/L) in January, April-
May and September. While spraying, care should be taken to spray the spindle
leaf and 2-3 adjacent leaves
Leaf Rot of Coconut
19. Symptoms
Exudation of reddish brown liquid through cracks developing on stem.
Decaying of tissues at bleeding point
Vigour and yield declining.
Development of big holes inside the trunk
Management practices
Chisel affected tissue and dress the wound with 5% Calixin (5 ml in 100
ml water).
Apply coal tar after 2 days. Burn off chiselled pieces.
Avoid any mechanical injury to the stem.
To avoid spread of disease on to upper portion of trunk, root feeding
with 5% calixin may be adopted 3 times a year - April-May, Spetember-
October and January-February.
Along with 50 kg organic manure, apply 5 kg neem cake containing
the antagonistic fungi, Trichoderma culture to the basin during
September.
Provide adequate irrigation during summer and drainage during rainy
season.
Apply recommended doses of organic manures and chemical fertilizers.
Coconut stem boring insects like, Xyleborus, Diocalandra should be
controlled by applying Carbaryl 50% WP on the trunk @ 3g per litre
water.
Stem Bleeding of Coconut
20. Middle aged palms are more fatally affected. Palms bear profusely just
prior to and at the initiation of symptoms.
Symptoms
Outer whorl of leaves wither and droop with yellowing and browning.
The outer whorl of leaves remaining suspended vertically around the stem
for a long time to form a skirt of dead leaves around the trunk (Plate31).
Leaves break or buckle very close to their bases. Successively produced
leaves are smaller and the crown is reduced to a mere handful of short
erect yellow leaves (Plate 32). Apex of the trunk tapers. Drooped leaves
fall off one by one leaving only a few smaller leaves at the apex.The
newly formed leaves are pale and smaller in size. Finally smaller leaves
wither and bud decays. Crown is easily blown off by wind. Rotting of the
basal portion of the stem is very characteristic (Plate33). Brittle bark often
gets peeled off in flakes leaving open cracks and crevices. Bleeding of
reddish brown viscous fluid with the decayed tissues beneath. (Plate34) It
is restricted to basal portion of the stem (0.1-1.5 m) from the base
(Plate35). The internal tissues are discoloured, disintegrated and emitting
a bad smell. Bole decays rapidly resulting in the formation of large
cavities. Extensive damage of the root system following rotting and
disintegration of cortical tissues. Necrosis of male flowers and poorly
developed few female flowers in the inflorescence, arrest the
development of bunches and barren nuts. Bracket shaped shiny waxy
brown frutification of the fungus at the base of the trunk after the death of
the palm (Plate 36, 37).
Basal Stem Rot / Tanjore Wilt / Foot Rot / Ganoderma Wilt / Anabe Roga of Coconut
Bleeding of reddish
brown viscous fluid
yellowing
Exudation of reddish
brown fluid
21. Causal Organism : Ganoderma lucidum, Ganoderma applanatum and G. boninense
Spread of Disease
Fungus is soil borne inhabiting in roots of dead as well as living woody plants in the soil. Prolonged
drought, high soil temperature, low rainfall, extensive flooding, sandy or sandy loam soils, presence of hard
pan in the sub-soil and neglected gardens are conditions favourable for the disease incidence
Management practices
1. Practice growing banana as intercrop in coconut.
2. Practice clean cultivation and burn off diseased plant pests.
3. Isolate infected palms by making trenches of 1m depth and 0.5 m width around the palm at 1.5 m
away from it.
4. Completely remove dead palms and palms in advanced stage of the disease. Burn the boles and root bits
of the palms
5. Isolate the affected palm from the healthy ones by digging a trench of 1m deep and 50cm wide at 2.0m
away from the bole of the infected palm
6. Add 50 kg farmyard manure or green leaves per palm per year. Reduce fertilizer application to one
fourth of the recommended dose
7. Root feeding with Calixin (2 ml in 100 ml water) once in 3 months.
8. Drench the basin with 40 litres of 1% Bordeaux mixture or 0.1% calixin (1ml/L) after soaking soil,
at quarterly interval for one year
9. Root feeding of 2 g Aureofungin-sol + 1g of Copper sulphate in 100 ml of water or Calixin 2ml in
100 ml water at quarterly interval
10. Avoid flood irrigation or ploughing in infected gardens to prevent spread of inoculums and follow drip
irrigation. Regularly irrigate basins during summer months or conserve moisture by coconut husk burial
11. Apply neem cake containing Trichoderma @ 5kg /palm/year. Apply Trichoderma harzianum
fortified in neem cake /compost / vermicompost / other organic wastes.
BASAL STEM ROT / TANJORE WILT / FOOT ROT / GANODERMA WILT / ANABE ROGA OF COCONUT
22. Symptoms
Characterised by emergence of shorter leaves with fascinated
and crinkled leaves.
The leaflets show severe tip necrosis and fail to unfurl. In
many cases, it gives a choked appearance to the frond.
Ultimately the affected palm dies.
Control measures
Application of 50 g Borax at half-yearly intervals (Feb-Mar
and Sept-Oct) along with recommended fertilizer in the basins
will control the disease when it is in the early stage.
In root wilt affected areas a dosage of 200 – 300 gm per palm
per year is recommended.
Crown Chocking of Coconut
23. Symptoms
Minute yellow spots encircled by greyish bands appear on the
surface of mature leaves of the outer whorl.
Later they become greyish white. These spots coalesce into
irregular necrotic patches.
Complete drying and shrivelling of the leaf
blade are common when the infection is severe.
Control measures
Removal of the older 2-3 disease affected leaves
and spraying the foliage with 1% Bordeaux
Mixture will check the spread of the disease.
Leaf blight or Grey Leaf Spot of Coconut
24. Symptoms
Palms of 20-40 year old are highly susceptible
Appears on the leaflets of mature leaves of the outer whorls of palm
Yellowish brown oval spots of 1-5 cm long with grey brown margins appear on leaflets
(Plate23)
The centre of the spots become greyish white, while the brown colour of the margins
deepens
Many spots coalesce to form larger irregular necrotic patches causing extensive leaf
blight (Plate24)
The fruiting bodies (acervuli) of the fungus appears as black minute dots / specks
(Plate25)
In advanced stages, the tips and margins of the leaflets dry and shrivel giving a burnt
appearance (Plate26)
Premature shedding of leaves and reduction in the number of leaves prolong the
prebearing age of young palms
Causal Organism
Pestalotia palmarum
Spread of Disease
Spread is through air borne conidia. Disease intensity is severe during rainy season with
low temperature and high humidity. Poor soil nutritional status, especially potash
deficiency increases the disease incidence.
Management
Remove severely affected older leaves and burn
Spray the crown with 1% Bordeaux mixture or 0.3% tilt (3ml/L)
Apply higher dose of potash (25% extra) along with recommended dose of NPK
Apply increased dose of farmyard manure and composted coir pith (@100 kg/palm/year)
CGD, COD and their hybrids are tolerant
Leaf blight or Grey Leaf Spot of Coconut
25. New coconut plantation at north farm is 5 years old.
The coconut plantation consisted of around 496
growing seedlings planted along road side spaces.
Out of these, approximately 70 % of newly planted
coconut seedlings were observed to be infected by
leaf spot disease caused by Pestaliopsis palmarum.
The affected plants were severely infected with the
disease with large spots visible from a long distance
on almost dried leaves (Figure) and were dying.
Copper oxy chloride (Blitox 50 WP) was
immediately sprayed @ 0.5 % along with NPK
fertilizer and irrigation. Chlorothalonil was also good
for it.
Our careful attention and intervention saved the
plantation from disaster.
Management of Leaf blight or Grey Leaf Spot
of Coconut caused by Pestaliopsis palmarum
at North Farm, CRIJAF, Barrackpore
26. Symptoms
First appeared in Tatipaka village of East Godavari district of
Andhra Pradesh, following a cyclone in 1949.
Palms in the age group of 25 to 60 years are more susceptible.
Development of an abnormally large crown with dark green
inner leaves
Higher yield is the precursor of disease incidence.
Subsequently the crown becomes smaller in size producing
progressively shorter leaves.
The stem begins to taper. The leaves give a fascinated
appearance due to improper unfolding of leaflets.
The affected tree produces smaller bunches with atrophied
barren nuts.
The causal agent is suspected to be Phytoplasma.
Tatipaka Disease of Coconut
27. Symptoms
Affect palms of all ages especially on outer whorls of
mature leaves. Burnt or dried appearance of outer whorls
of leaves (Plate 27). Reddish brown oval to irregular
sunken lesions with dark brown margin on leaves (Plate
28). Salmon or reddish brown fruitification of the fungus
as dots on the affected leaves (Plate29). Lesions coalesce
resulting in leaf blight (Plate30). Disease progress to mid
whorl of leaves causing premature drying and falling of
leaves.
Causal Organism
Colletotrichum gloeosporioides. The disease is air borne
Management
1. Remove and destroy severely affected leaves.
2. Spray 1% Bordeaux mixture or Mancozeb 0.4%
(4g/L) on outer and mid whorls of leaves at 45 days
intervals.
3. In severe case, spray 0.3% (3ml/L) Propiconazole
(Tilt) / Hexaconazole (Contaf) at monthly interval.
ANTHRACNOSE AND LEAF BLIGHT
Burnt or dried
appearance
Reddish brown
sunken lesions
premature drying
29. • Killing of pathogens with other living organism
• Kills by competition, mycoparasitism and
antibiosis (toxin or enzymes)
• PROCESS: Biocontrol agents are isolated from
nature, tested on pathogens in lab, mass
cultured on cheap media, tested viability and
then applied in field.
• Examples in jute: Fungi –Trichoderma spp.,
Aspergillus niger,
• PGPR – Promotes plant growth, suppresses
disease, e.g., Fluorescent Pseudomonas
BIOLOGICAL CONTROL