Introduction
- The coconut is essentially a cash crop though in certain countries such as
India, Ceylon, etc., it is also a food crop in the sense that coconut kernel and
oil invariably find a place in the dietary of the inhabitants.
- The main consideration
in plantation management should, therefore, be to maximise the net income from
it and this can be achieved only by increasing production, reducing costs, creating
additional sources of income, proper disposal of major and minor products, etc.
Top Management Practices
- The poor productivity of most of the coconut plantations is undoubtedly due
to faulty, improper or inadequate soil management.
- A fuller appreciation of
this fact and a systematic adoption of improved practices will help to step up
production.
- The important soil management practices that are to be given due
consideration in relation to the coconut are : tillage, drainage, mulching, erosion
control, cover cropping, manuring, replenishing organic matter, husk-burying,
use of soil amendments and ameliorants.
- The need for and the importance of
each of these practices will differ with the soil type, situation, condition,
etc.
- For example, in a heavy soil, the primary object will be to make it more
porous, whereas in a lighter soil, the main concern will be to improve its water
and nutrient retaining capacity.
- Again, in a sloping land, more than anything
else, the essential need is to conserve the soil.
- Some soil management practices
that are adopted in coconut are as follows.
Tillage
- In coconut gardens, inter-cultivation or cultivating the interspaces
is the main tillage operation and consists of ploughing, harrowing and digging.
- The objects of tillage in a coconut garden may be summed up as follows:
- To make the soil receptive to the first rains after a rainless period, and
to retain more moisture.
- To produce favorable tilth or soil structure for
the development of roots, thereby increasing the available feeding area for the
palm.
- To improve the aeration of the soil resulting in increased bacterial
and chemical activity which in turn increases the available plant food in the
soil.
- To kill weeds and thereby conserve both plant food and water for the
palm.
- To incorporate organic matter into the soil.
- Under
the soil and climatic conditions obtaining on the West Coast of India, regular
cultivation is found to help in conserving soil moisture, through the combined
effects of weed removal, better percolation of water to sub-soil layers and reduced
loss of moisture by evaporation from soil surface.
- Cultivation is an important
item of expenditure in the maintenance of a coconut garden and it is therefore
necessary to limit it to the irreducible minimum.
- To get the maximum benefit
from cultivation, a number of factors have to be taken into consideration, such
as form, frequency, time and depth of intercultivation, etc.
- In the coconut
tracts of India, different cultivation practices such as ploughing, digging with
spade, opening basins and covering them, forming bunds and subsequent levelling
etc., are being followed by progressive growers.
- The cost involved varies
with the different operations and a correct evaluation of them under similar conditions
is necessary before a particular practice is advocated.
- Ploughing is the cheapest
of the above, yet a small grower may prefer to dig up his garden with spade.
- Where
the soil is light, cultivation can be done with hoes or harrows with ease and
rapidity at less cost.
- Cultivation is to be practiced at the proper time,
taking into consideration the incidence and distribution of rainfall, soil type
and slope of the land.
- The soil should be ploughed only when it contains proper
amount of moisture lest it should spoil the structure of the soil and create hard
pans.
- In sloping lands, ploughing may be done along the contour after the
heavy monsoon rains are over, in order to avoid the risk of soil erosion.
- The
depth of inter-cultivation, has to be determined with reference to the depth of
soil, the height of water table, the condition and distribution of the root system,
etc.
- Shallow cultivation should be preferred in order to avoid damage to the
root system.
- This is particularly important when the area of root spread is
restricted or the palms are weak, because then rejuvenation of roots does not
take place satisfactorily.
- If the soil is deep and the palms healthy, cultivation
has the effect of forcing the roots to go to lower layers where they do not suffer
much during drought periods.
- The garden should be cultivated when the soil
has become hard and compact or when it is foul with weeds.
- Too frequent cultivation
can prove harmful under tropical conditions, as it may accelerate the depletion
of soil organic matter.
- The weeds may be incorporated into the soil by ploughing
or by burying them in trenches where they will rot in course of time and augment
the organic matter content of the soil.
- As the primary object of cultivation
is to reduce weed growth, it should be done before the weeds flower and set seeds.
Mulching - Mulching is the practice
of covering the surface of the soil with a layer of vegetable waste material,
with a view to keeping the surface layers at a more even temperature, more premeable
to water and for reducing weed growth.
- Though considerable literature has
accumulated on the effects of mulching on other horticultural crops, comparatively
little is found reported in respect of the coconut.
- The materials that can
be used for mulching are husks, leaves and fibre dust.
- These materials though
available in large quantities in Ceylon and other countries, are difficult to
obtain in India for mulching purposes.
- Mulching with husks upto a distance
of 2 m from the base of the bearing tree is being done in Ceylon and has been
reported to help in conserving moisture and preventing weed growth.
- In India,
mulching with dry coconut leaves during summer did not have any marked beneficial
effects on the palms growing in sandy soil.
- Mulching should be done at the
end of the rainy period.
- The preliminary observations on the use of coir dust
as mulch in Ceylon appeared to show that it can conserve soil moisture but has
no effect on immature nut-fall.
Cover Cropping
- The growing of cover crops in coconut plantations is now becoming
more and more popular in coconut growing countries. Cover crops are those crops,
which are able to make vigorous growth and cover the ground densely in a short
period of time.
- As distinct from a catch crop, a cover crop is chosen more
with regard to the interest of the main crop than of the cover crop itself.
- The
following are the benefits expected by growing the cover crops.
- Prevention
of soil erosion.
- Smothering of weeds thus reducing weeding costs.
- Addition
of organic matter to the soil and thus maintaining the structure of the topsoil.
- Improving aeration of the soil.
- Protecting the soil and roots of crops
from excessive heat of the sun.
- Conservation of fertility by using available
plant food which might otherwise be leached away.
- Fixing of atmospheric nitrogen
from the air in the case of leguminous plants.
- Taking away moisture and nutrient
supply from the soil, thus reducing the amounts available to the trees.
- This
will check fresh wood growth and produce conditions favourable for proper ripening
and better colour of the fruits.
Erosion
Control - Soil erosion is a really serious problem in gardens raised
on hill slopes, particularly in areas where heavy rains are received.
- The
loss of fertile top soil exposes the roots of the palm and creates plant food
deficiencies with the result that the palms look diseased and become unproductive.
- The importance of taking adequate measures for the control of soil erosion
cannot, therefore, be over emphasized.
- A number of methods such as terracing,
contour bunding, cover cropping, building crescent bunds, etc. suited to different
situations.
Top Intercropping
- In coconut gardens where the palms are planted 7.5 m to 9 m apart the interspaces
might appear to offer opportunities for raising other crops, annuals or perennials,
as a source of additional income to the grower.
- In fact, a variety of crops
depending upon the soil and climatic conditions and local demand are being grown
in the gardens of small growers.
- In the early stages of the plantation, when
the seedlings are still young and the ground is unshaded, there is no harm in
raising such crops, provided care is taken to see that the subsidiary crops are
well manured and that they are not grown to the very base of the palms.
- It
is better to leave uncropped about 2 m all round the base of the palms and keep
the area free of weeds by repeated cultivation.
- Manures for the young palms
can be applied in this area and incorporated.
The
crops commonly cultivated in young plantations in India are - Tapioca
(Manihot utilissima), sweet potato, banana, yams (Amorphophallus companulatus),
colocasia (Colocasia antiquorum), turmeric (Curcuma longa), ginger (Zingiber officinale),
paddy (Oryza sativa), ragi (Eleusine coracana), jowar (Sorghum durra), sugarcane
(Saccharum officinarum) and crops like horse gram (Dolichos biflorus), cowpea
(Vigna catjang), green gram (Vigna mungo), pine-apple (Ananas sativus) and different
kinds of vegetables.
- The subsidiary crops can and are being raised in the
adult plantations also, but, because of the shade of the canopy of the overhanging
leaves, the range of crops that can be grown is limited and the yield that can
be obtained will also be much less than in the open have shown, that, the subsidiary
crops with proper attention to manuring can be grown without in any way affecting
the yield of the coconut palms.
- In fact, subsidiary crops raised with adequate
manuring and irrigation have been found to considerably benefit the coconut palms.
- The results can certainly be adverse if crops which are heavy potash feeders
such as tapioca are grown without manuring continuously for long periods.
- In
Ceylon, Napier grass (Pennisetum purpureum) grown without manuring was found to
depress the yields of the coconut.
- In Brazil, Manihot (cassava) is recommended
to be grown in coconut plantations because of the reported favourable effects
on soil permeability and moisture conservation.
- The practice of growing trees
of a perennial nature along with the coconut is also widely prevalent in the coconut
areas particularly in the holdings of small growers.
- Mango (Mangifera indica),
jack (Artocarpus integrifolia), Arecanut (Areca catechu), bead fruit (Artocarpus
incisa) and other trees which satisfy some of the needs of the growers are found
grown in the coconut gardens on the West Coast of India.
- Rubber and coffee
(Coffea sp.) are also sometimes found grown.
- In Malaya, coffee, mangosteen
(Garcinia and Seychelles, clove (Eugenia caryophyllata) is being raised.
- In
some coconut growing countries cocoa (Theobroma cacao) is also being interplanted
with coconut.
- Intercropping of perennial plants in gardens where palms are
planted adopting the usual spacing is not be encouraged as such cropping will
result in intense competition and adversely affect the growth and performance
of both the crops.
- Such intercropping will further make it rather difficult
to give proper attention to the different kinds of trees according to their special
and individual requirements.
- If, however, it is desired to raise other trees
also, to diversity the sources of income of the grower, two ways are open.
- One
is to plant the trees in alternate rows giving sufficiently wide spacing to reduce
mutual interference of one over the other and the second is to assign different
portions of the available area among the different crops.
- The latter is better
than the former.
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