The coconut palm is referred to as 'Kalpavriksha' - the 'tree of heaven' as each and every part of the palm is useful to mankind in one way or other. It provides food, drink, fuel and timber. Millions of families in India depend on coconut for their livelihood either directly or indirectly India ranks third in area and production of coconut in the world. The four southern states viz . Kerala, Tamil Nadu, Karnataka and Andhra Pradesh are the major coconut producing states in India accounting for more than 90 per cent of area and production. There is a great scope for enhancing the productivity of coconut through adoption of scientific cultivation technologies, which are described here under.
The coconut palm is found to grow under varying climatic and soil conditions. It is essentially a tropical plant, growing most!y between 20° N and 20° S latitudes. The ideal temperature for coconut growth and yield is 27 ± 5° C and humidity > 60 per cent. The coconut palm grows well upto an elevation of 600 m above MSL. However, near the equator, productive coconut plantations can be established up to an elevation of about 1000 m above MSL. The palms tolerate wide range in intensity and distribution of rainfall. However, a well distributed rainfall of about 200 cm per year is the best for proper growth and higher yield. In areas of inadequate rainfall with uneven distribution, irrigation is required.
Basically, coconut cultivars are classified into two groups viz., tall and dwarf.
The tall cultivars that are extensively grown are the West Coast Tall and East Coast Tall. The dwarf variety is shorter in stature and its life span is short as compared to the tall. Tall x Dwarf (TxD), Dwarf x Tall (DxT) are the two important hybrids.
There are 10 different combination of hybrids, developed by Kerala Agriculture University and Tamil Nadu Agriculture University and released for commercial cultivation. They are high yielders under the good management conditions. Laccadive Ordinary, Andaman Ordinary, Philippines, Java, Cochin-China, Kappadam etc. are the other tall cultivars under cultivation.
Coconut is propagated through seedlings raised from selected seednuts. Generally 9 to 12 month old seedlings are used for planting. Select seedlings, which have 6-8 leaves and 10-12 cm collar girth when they are 9-12 month old. Early splitting of leaves is another criteria in the selection of coconut seedling.
Shallow soils with underlying hard rock, low lying areas subject to water stagnation and clayey soils are to be avoided. Proper supply of moisture either through well distributed rainfall or through irrigation should be ensured before planting.
On slopes and in areas of undulating terrain, prepare the land by contour terracing or bunding. In low-lying areas mounds are to be formed at planting site to a height of at least 1m above water level. In reclaimed ‘kayal’ areas, seedlings are planted on field bunds.
In loamy soils with low water table, a pit size of 1mx1mx1m is recommended. In laterite soils with underlying rocks, take larger pits of size 1.2m x 1.2m x 1.2m. In sandy soils the size need not exceed 0.75m x 0.75m x 0.75 m.
Spacing depends upon the planting system, soil type etc. In general the following spacing are recommended under different planting system in sandy and laterite soils.
|Square||7.6x7.6m, 8x8m, 9x9 m|
|Single||6.5m in rows - 9m between rows.|
|Double Hedge||6.5 to 6.5m in rows - 9m between pairs of rows|
Seedlings can be transplanted in the beginning of the south west monsoon. If irrigation facilities are available, it is advisable to take up planting at least a month before the onset of the monsoon so that the seedlings get well established before heavy rains. Planting can also be taken up before the onset of the north-east monsoon. In low-lying areas subject to inundation during monsoon period, transplanting may be done after the cessation of the monsoon.
Before planting the pits are filled up with top soil and powdered cow dung / compost up to a depth of 50 to 60 cm. Then take a small pit inside this, so as to accommodate the nut attached to the seedling. Plant the seedling inside this pit and fill up with soil. Press the soil well so as to avoid water stagnation. If there is chance for white-ant attack apply Sevidol 8G (5gm.) inside the small pit before planting.
In laterite areas apply 2 kg common salt per pit for improving the physical condition of the soil. Burying 25 to 30 coconut husks per pit in layers will be useful for moisture conservation.
The transplanted seedlings should be shaded and irrigated adequately during the summer months. Also provide staking so that winds may not uproot the young seedlings. For the first two years after planting, irrigate the seedling twice a week during the dry summer months. Shading is a must to the transplanted seedlings.
Regular manuring from the first year of planting is essential to achieve higher productivity. For coconut 20 - 50 kg organic manure should be applied per palm per year with the onset of south west monsoon, when soil moisture content is high. Different forms of organic manures like compost, farm yard manure, bone meal, fish meal, blood meal, neem cake, groundnut cake etc. could be made use for this purpose. In addition to this the following Fertilizer Schedule is recommended.
The fertiliser schedule recommended for the palm at different stages is as follows:-
|Quantity of fertilizer to be applied (gm)|
|Age of Palm||Nutrient dosage||Ammo. Sulphate||Urea||Super Phosphate (single)||or Ultraphos/ Rock Phosphate||Muriate of Potash|
|1. General recommendation: |
(a) Average Management:
|3 months||1/10 of full dose||165||75||95||60||115|
|1 year||1/3 of full dose||550||250||320||200||380|
|2 year||2/3 of full dose||1100||500||640||400||760|
|3 year onwards||full dose||1650||750||950||600||1140|
|(b) Good management:|
|3 months||1/10 of full dose||250||110||180||115||200|
|1 year||1/3 of full dose||800||360||590||380||670|
|2 year||2/3 of full dose||1675||720||1180||760||1340|
|3 year onwards||full dose||2000||1080||1780||1140||2010|
|2. Hybrid and high yielding palms: |
a. Under Irrigated condition:
|3 months||1/10 of full dose||490||220||280||180||335|
|1 year||1/3 of full dose||1625||720||930||600||1110|
|2 year||2/3 of full dose||3250||1450||1850||1200||2220|
|3 year onwards||full dose||4880||2170||2780||1800||3330|
(b) Under rainfed condition:
The full adult doze recommended for the rainfed tall is 0.34kg N, 0.17kg P and 0.68kg K. For the hybrids and irrigated talls the general recommendation is 0.5kg N, 0.34kg P and 1.0kg. K subject to changes in accordance with soil test and/or foliar analysis data.
In addition to the above dose of fertilizers two to three kgs. of finally ground dolomite lime stone or 0.5 kg. Magnesium sulphate per palm per year is also recommended for use in acidic soils, light sandy soils and in root wilt affected tracts in Kerala. The dolomite may be broadcasted prior to the onset of monsoon in the basins and forked in and should not be applied along with other fertilizers. There is however no harm in applying magnesium sulphate along with other fertilizers.
Soil moisture very often limits coconut production in those areas where long spell of dry weather prevail or where the rainfall is scanty and ill-distributed. So irrigate the palms during summer months in basins around the palm. The irrigation requirement varies according to the soil type and climatic condition. Generally, an adult palm requires 600 to 800 litres of water once in four to seven days. Irrigate in basins of 1.8m radius and 10-20 cm depth. In coastal sandy soils, sea water can be used for irrigating adult palms. Do not irrigate seedlings and very young palms upto 2 year with sea water. In irrigated gardens interruption of irrigation would lead to serious set-back in yield and general condition of palms. Hence, when once started irrigation should be continued regularly and systematically. Drip irrigation is the best suited method of irrigation for coconut. It saves water, labour and energy.
Only minimum tillage is required for coconut. Inter-cultural operations are mainly intended to control weeds and to provide aeration to the soil. If these objectives are met, any tillage system (ploughing / digging, making mounds) is as good as another and can be followed depending upon the local conditions.
Burying fresh or dried coconut husks around the palm is a very beneficial practice particularly for moisture retention especially in drought prone areas. The husk can be buried either in linear trenches taken 3 m away from the trunk between rows of palms or in circular trenches taken around the palm at a distance of 2 m from the trunk. The trenches may be dug at 0.5 m wide and at the same depth. The husks are to be placed in layers with concave surface facing upwards and covered with soil. The beneficial effects of husk burial will last for about 5-7 years.
This will help to increase the organic matter content of the soil and also will prevent soil erosion in coconut gardens. The following Green manure / cover crops are recommended for cultivation in coconut gardens.
Sow the green manure / cover crops during April-May with the onset of pre-monsoon showers. The green manure crops should be ploughed in and incorporated in the soil during August-September.
Schedule for inter-mixed cropping may be drawn up based on the canopy size and orientation of palms. A variety of intercrops like pineapple, banana, elephant-foot yam, groundnut, chillies, sweet potato, tapioca and different vegetables can be raised in coconut garden. In older plantation cocoa, cinnamon, pepper, clove, nutmeg etc. can be grown as mixed crops. However, these inter/mixed crops are to be adequately and separately manured in addition to the manures applied to the coconut palm
Mixed farming by raising fodder grasses such as Hybrid Napier or Guinea grass along with leguminous fodder crops such as Stylosanthes has been found to be profitable. Raising the above crops in one ha. of coconut garden can support three to four diary animals. The animals supply large quantities of cattle manure which when applied to the soil will improve its fertility status. This sort of mixed farming will improve the yield of the palm.
The major insect pests of the coconut palm are the rhinoceros beetle, the red palm weevil, the black headed caterpillar, the cockchafer beetle and the coreid bug. Adopt suitable remedial measures as and when required. The following table gives the major symptoms and control measures.
The adult beetle bores into the unopened fronds and spathes. Attacked fronds when fully opened show characteristic geometric cuts.Control measures
As a prophylactic measure, fill up the top most three leaf axils with Sevidol 8G(25g) + fine sand (200g) thrice in April, September and December.
Place 10.5g naphthalene balls in the leaf axils and cover it with fine sand.
To be practiced once in 45 days.
Spraying 0.01% Carbaryl (50WP) in the breeding sites of the beetle help destroy the larva.
Biological control using the virus Baculovirus oryctus (release 10 - 15 virus infected beetles in 1 ha
Green muscardine fungus, Metarrizhium anisopliae (spray 250ml Metarrizhium culture + 750ml water in manure pits and other breeding sites of the beetle)
Practice clean cultivation.
Red Palm Weevil
Presence of holes on the stem, oozing out of viscous brown fluid and extrusion of chewed up fibres through the hole.Some times the gnawing sound produced by the feeding grubs will be audible.
Black headed Caterpillar
Severity of attack is seen during January to May. The caterpillar feeds on green matter from lower leaf surface, remaining within silk and frass gallaries. In severe attack all the green matter of the leaves will be eaten up.
Biological control is very effective against this pest through release of parasitoids like Gorriozus nephantidis, Elasmus nephantidis and Brachimeria nosatoi. In case of severe attack, remove the affected leaves and destroy by burning. Then spray the under surface of leaves with 0.02% Dichlorvos (Dichlorvos 100EC).
The attacked buttons do not develop resulting in immature nut fall. The nuts if developed may become barren.
Pesticide application is necessary if infection is severe. Spraying has to be done 3 times a year. Apply 0.1% Carbaryl on the inflorescence after the receptive phase of the female flowers. Destruction of pollinating insects can be avoided if spraying is done in afternoon hours. Tying perforated polybags (2 bags/palm) containing 2.5g phorate on to the stalk of inflorescence is also effective.
Symptoms - Attack tender nuts resulting in immature nut fall.
Mealy Bugs and Scale InsectsSymptoms - During summer months mealy bugs cause damage to spindle leaves, spathes and bunches and the scale insects make encrustations on the foliage. The infested turn yellow and finally dry up.
Two rounds of spray with 0.1% Fenthion or 0.05% Monocrotophos.
In the case of scale insects spraying with dimethoate or monocrotophos 0.05% is efficacious.
TermitesSymptoms - It is estimated that nearly 20% of the coconut seedlings are damaged by termites particularly in laterite soil.
White Grub - (Leucopholis coneophora Burm.) (Melolonthinae: Coleoptera)Symptoms
The white grubs are mostly found in sandy loam tracts of Kerala and Karnataka. It damage the roots. In seedling, it tunnels in to the bole and collar region.
It has an annual life cycle with a grub period of 8 months. Peak grub population is observed from Sept. to Oct. Adult beetles emerge out of the soil after pre- monsoon showers in May-June during sunset hours.
The Eriophid Mite (Aceria guerreronis (Keifer) (Acarina: Eriophyidae) which was a minor pest of coconut in India has become a major pest on coconut recently.
The attack of this mite was first recorded in 1965 in Guerrero, Mexico. Later it was reported from Ivory cost, Brazil, Costa Rica etc. The first Indian report of this pest is from Ernakulam District of Kerala during 1998. The sporadic occurrence of this pest is reported from almost all the 14 districts of Kerala, Tamil Nadu, Karnataka, Andhra Pradesh and Kalpeni Island of Lakshadweep.
The mites are very minute in size and are not visible by naked eye. The size of this measures to 200-250 microns in length and 20-30 microns in width. The life cycle of this mite is completed in 10-12 days. It remains underneath the periyanth (cap) and cause injury by feeding on the soft paranchymatic tissues. Though the mites are microscopic their damage is enormous and hundreds of mites could be seen in each infested button and tender nut. Visible symptoms are brown discolouration noticed in patches of the husk. In case of severe attack the button sheds, resulting in very poor setting percentage. In other cases the nuts are deformed and undersized with poor development of kernel and husk.
The mites spread through wind and its multiplication is at a high rate. Though this pest was noticed only in a limited area during 1998 it has become a major pest of coconut in India.
Being a micro pest inhabiting under the periyanth, the control measures at field level are not easy. However by adopting the following integrated plant protection measures the mite population could be reduced considerably.
Source : Coconut Development Board