 PLANT
PROTECTION
B.
Diseases
The
coconut palm is affected by a number of diseases,
some of which are lethal while others gradually
reduce the vigour of the palm causing severe loss
in yield. A brief account of the important coconut
diseases is given.
VI.
Mahali
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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.
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Control
measures
-
Spray
1% Bordeaux mixture on the crown of
the palm once before the monsoon and
later after 40 days interval.
-
Remove
and destroy fallen nuts.
-
In
dwarf palms, apply Dithane M-45 in place
of Bordeaux mixture.
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VII.
Crown Chocking
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 200gm -
300gm per palm per year is recommended.
VIII.
Leaf blight or Grey Leaf Spot
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.
IX.
Tatipaka Disease
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 and
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 Phytoplasm.
For details regarding Pests
of Coconut click here: Pests
For more details please contact
us:
E-mail: cdbkochi@dataone.in
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