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Garden management - Cocoa |
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Nutrient Requirement
Cocoa requires 100 g N (220 g urea), 40 g P2O5 (200
g rock phosphate) and 140 g K2O (235 g muriate of potash) per
year.
One third of the fertilizer is applied in May - June and two third
during September-October.
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Pruning
The cocoa tree is to
be pruned regularly to maintain good canopy.
In young cocoa it is necessary to have formation pruning.
This is done mainly to adjust height of first jorquette.
The jorquette is allowed to form at a height of 1-2 m, which will
help in undertaking cultural operations. Pruning
in mature cocoa includes two types viz., sanitary pruning and structural
pruning. In sanitary pruning,
diseased or unnecessary branches are removed.
Structural pruning is done to shape the canopy to desired size and
architecture. Maximum leaf
area should be maintained with pruning practices to avoid self-shading of
leaves. Cocoa grows in a
series of storeys. The chupon
or vertical growth of plant terminates at the jorquette where 4-5 fan
branches develop. Further
chupon develops just below jorquette and continues vertical growth till
another jorquette is formed. When
grown as intercrop of palms, it is desirable to restrict the height of
canopy to two storey level. In
studies on spacing and pruning,
it has been found that a spacing of 2.7 x 5.4 m and a canopy area of 15-20
m2 was found to give highest bean yield. |
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Irrigation
Cocoa is usually grown in
areas where water availability is adequate.
But in some areas although plenty of water is received, long
periods of dry spells ranging from 3-6 months are common.
Since cocoa plants are sensitive to drought, irrigation in such
cases are essential.
During summer, as it exists
in Southern India, the crop is irrigated at weekly intervals. When it is grown as mixed crop with arecanut, the crop is to be
irrigated once in a week during November-December, once in 6 days during
January-March and once in 4-5 days during April-May with 175 litres of
water. Cocoa responds to drip
irrigation well. Maximum
yields are obtained in cocoa irrigated through drip with 20 litres/day/tree
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Can we reduce the doze of
inorganic?
Based on
experiments conducted nationally and internationally, it has been well
accepted that soils with 1% organic C status was ideal for coconut
cultivation. Further,
long-term observations led to conclude that 70 to 80 ppm of mineralizable
nitrogen in soil and 10 to 12 ppm Bray extractable 'P' can sustain
sufficient levels in coconut.
Further work at CPCRI revealed that if soil available P is less than 10
ppm, full recommended dose of 320g P2O5/palm/year
may be applied and for a soil test value of 10 to 20 ppm, 50 per cent of
the same may be applied. For
soil test values of more than 20 ppm, P application can be skipped.
The various data on leaf analysis and nutrient responses available
in the country suggest the following critical levels (14th Frond ) for
coconut:
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N |
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1.7 - 1.8 per cent
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P |
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0.11- 0.12 per
cent
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K |
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0.8 - 1.0 per cent
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Ca |
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0.3 per cent
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Mg |
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0.2 per cent
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Some leguminous plants are capable of contributing
large quantities of green leaf manure and nitrogen to the coconut
palms by symbiotic nitrogen fixing bacteria, Rhizobium in their root nodules.
Peuraria phaseoloides, Mimosa invisa and Calapagonium mucunoides
are the most suitable legumes. They contribute 15-25 kg of wet biomass and
150-200 g of nitrogen in the basin of a coconut palm during its 5 months
growth in monsoon period as found in the experimental trial at our research
farm. This consequently resulted in significant improvement in soil
fertility and the yield of coconut palms
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Biofertilizers
The root regions of coconut palm are inhabited by a
number of free living and associative symbiotic nitrogen–fixing bacteria
having nitrogenase activity. The association of N2 –fixing Azospirillum
amazonense with the roots of coconut palm has recently been confirmed.
The other associative nitrogen fixers include Azospirillum
lipoferum, Azospirillum brasilense, Herbaspirillum
frisingense, Bacillus spp., Burkholderia
spp., Azoarcus
spp., Arthrobacter spp. and many
more which are yet to be
identified. Some of these are capable of fixing nitrogen even in the
presence of nitrogen fertilizer. These organisms may have additive or
synergistic effects on plant growth and health if they function in concert
in the rhizosphere of coconut palms.
Microbial
combinations may have very great potential for plant growth enhancement.
While raising coconut seedlings in coir dust-soil mixture, Beijerinckia indica and associative diazotrophs
such as Azospirillum,
Arthrobacter, Azoarcus, Herbaspirillum, Bacillus, Burkholderia and Pseudomonas
are promising microbiological inoculants which enhances the growth and
performance of seedlings.
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Vermicomposting
The local species of
Eudrilus
identified from coconut garden which is superior to other species in composting
of coconut plantation wastes.This earthworm can be
multiplied fast in a 1:1 mixture of cowdung and decayed organic wastes.
Keep 10 kg of this mixture in bucket and release 50 to 100 worms. Mulch
the mixture with grass and cover with a net. Maintain the moisture. In
1 to 2 months 150 to 300 g earthworm will be produced. |
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Irrigation
The coconut
plantations can be irrigated during summer months by hose irrigation, perfo/sprinkler
or drip system of irrigation depending on farmer’s resources and
convenience. The quantity of water, 200 l/palm once in four days for hose
irrigation, 20 mm water once in 4-5 days under perfo/sprinkler and 32
l/palm/day through four dripping points in drip systems is to be given from
Dec. to May months in the West Coast region of India. |
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Moisture Conservation
Coconut is mainly
grown under rainfed conditions in most coconut growing regions. For reducing
surface evaporation and improving water retention under rainfed conditions
and to reduce the erosion hazard the following conservation methods are
suggested.
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Mulching with
coconut husk, coir dust, green leaves, dried coconut leaves etc.
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Addition of organic
manures or green manure
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Husk burial- effect
lasts for 7 years
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Inter cultivation
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Bunding, terracing,
etc.
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Coconut harvest
Twelve months old nuts are harvested for seed as well
as copra making. However, for tender nut purposes 7 to 8 months old nuts are
harvested. In case of tall the nuts harvested for seed purpose can be
stored for 2 to 3 months period before sowing, whereas in case of dwarfs and
hybrids, nuts should be sown with in a period of 10 –15 days of harvest. On
an average, we can have eight harvests, though the coconut palm produces
inflorescence every month. For oil extraction, nuts are generally sun dried
for copra making. In this case there is a chance of dirt accumulation
followed by oil quality deterioration, nuts can be dried in various types of
driers available (Kiln, electric and solar driers). Good quality copra can
be obtained in short time by using these driers. Moisture content in copra
for final use should be around 5-6%. The oil yield of WCT palms under
rainfed condition will be around 1.7 to 2 tons/ha |
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