Coconut is a majestic perennial palm. It is grown in numerous islands and also in the humid coastal tracks of tropical countries. India ranks second in the world production of coconuts 6088 million nuts from 108 million hectares.
The coconut palm, or ‘kalpa vriksha’ provides many necessities of life like food and shelter. of all the tropical palms it is the outstanding one. It is mainly cultivated for the nuts from which 2 important products ‘copra’ and fiber are obtained. Copra yields oil and oil cake. The trunk of the mature palm is used as timber for houses and the leaves are used for thatching houses, fencing etc. The unopened spathe is tapped for toddy called ‘neera’. Sweet toddy can be converted into jaggery and sugar, fermented toddy is a mild alcoholic drink and vinegar can be made from it. Water from tender coconut is a refreshing drink. In kerela the extraction of coir from the husk of nuts and the manufacture of coir products provides employment for thousands of people. The coconut shell is largely used for fuel and for the production of charcoal and making a variety of curios. The shell flour is used as filler for plastics. Thus every part of the palm is useful in one-way or the other.
CLIMATE. Coconut is essentially a crop of the humid tropics. It is mainly grown in the coastal plains. Rainfall is the most important factor affecting its growth. A rainfall for 100 to 225 cm per annum, evenly distributed is most important.
Coconut requires an equable climate. The optimum mean annual temperature for its best growth and maximum yield is 27 deg Celsius. Frost and low humidity adversely affect the yield of the palm. Persistent high humidity is also harmful and bud rot is more common under such conditions. The palm requires bright sunshine of 2000 hrs a year.
SOIL. The coconut palm adapts itself remarkably well and thrives in almost all types of well-drained tropical soils, such as coastal sand, red loam, laterite, alluvial and reclaimed soil of the marshy lowland. A water table that is too high and remains static for too long is harmful.
PLANTING MATERIAL. Since coconut is a cross-pollinated perennial crop the selection of seeds is of vital importance. Selection has to be made at the mother-palm level and at the seedling stage. The mother palms should be healthy, high yielding and regular in bearing. Also factors such as proportion and distribution of female flowers, high setting percentage and a high copra content should also be taken into consideration. If progeny testing the yielding ability of can identify prepotent palms the planting material can be further assured. A careful selection of the seedlings is important. The seedlings should be healthy and have a minimum of six leaves when they are one year old. The early splitting of leaves is a desirable character. Nine-month-old seedlings having a minimum of four leaves can also be planted.
PREPARATION OF LAND. The clearing and leveling of land have to be done before preparing the pits for transplanting seedlings. The depth of the pit depends on the soil type. In the sandy loam of low water table the planting pits of the size 1mx1mx1m is recommended. In laterite soils with a rocky substratum, deeper and wider pits 1.2×1.2×1.2m are necessary. At the time of planting the pits have to be filled up with loose soil leaving a final depth of about 60cm. However when the water table is high planting on the surface or on soil mounds may be necessary. In a littoral sandy soil, circular pits 1.5mx1.5mx1.5m are made and partially filled with alternate layers of red earth and coconut husks(150 husks).
The spacing of palms requires careful consideration. A spacing of 7.5 to 9 m accommodating 177 to 124 palms per hectare is adopted under the square system of planting. The triangular method accommodates 20 to 25 more palms per hectare. In the hedge system of planting, a spacing of 5 to 5.5m along the row is given. Larger number of palms can be planted in a unit area ensuring sufficient light on each palm.
TRANSPLANTING AND AFTER CARE. In well-drained soils seedlings can be transplanted at the beginning of the southwesterly monsoon. If facilities for irrigation are available, it is advisable to take up planting at least a month before the onset of the monsoon. In the low-lying areas, seedlings are better transplanted after the rainy season.
The transplanted seedlings should be shaded and irrigated properly during the summer. Irrigation with 45 liters of water once in four days is the optimum in sandy soils. Provision for drainage is also important. Apply the complete NPK fertilizer from the early stage. The first dose should be applied 3 months after planting. The scheduled dose is given in table 4.
Large quantities of green leaf or compost to the soil can be applied where it has poor organic matter content. The pits should be cleared of all the weeds and the soil washed down by rain. The palms should be frequently examined for insect attack or fungus diseases and the necessary remedial action adopted promptly.
CARE OF ADULT PALMS. The palms generally start bearing at the age of five or seven years after planting and the stabilized yield is obtained from about the tenth year onwards for 50 to 60 years. Regular intercultivation and manuring of the palm are essential for stepping up and maintaining the productivity of palms at a high level. Tillage including digging, ploughing, piling of mounds, leveling of mounds, etc. and the making of shallow basins each with a radius of 2 m, at the beginning of the monsoon and filling them up at the close of the monsoon are beneficial. In sandy soils, which are of low fertility and do not have a luxuriant growth of weeds, regular intercultivation may not be quite necessary but in other types of soils, intercultivation is essential for keeping down the weeds under check and for creating a soil mulch. Table 4. Recommendations in terms of commonly available fertilizers (g/Palm/year)
The method of intercultivation mainly depends on the local conditions, soil type, topography, size of holding, intensity of rainfall, etc.
The recommended dose of fertilizers is 500g of N, 300g of P2O5 and 1,200g of K2O per palm per year for the ordinary tall variety. For soil which are poor in organic matter, the application of green manure or compost at 50kg per palm is recommended. Green-manuring crops usually grown are cowpea, sun hemp. Fertilizers may be applied in two spilt doses. After the receipt of summer showers one third of ht edose of fertilizers is spread around the palm within a radius of 1.8m and raked in. Circular basins 1.8m in radius and 25cm in depth may be dug in July-August and the green leaf manure or compost applied and partially covered. The remaining two-third dose of the fertilizers may be spread in the first week of September and the basins closed. Under irrigated conditions and in areas with assured supply of moisture throughout the year the annual dose of fertilizers may be applied every three months in equal split doses.
In regions with a long spell of dry weather, there is a definite set back in the growth and yield of the coconut palm. An increase of 50% to 100% in the yield of nuts can be obtained by giving summer irrigation. The quantity and interval between irrigations depend upon the soil and the climatic conditions. In loamy soils copious irrigation, once a week is sufficient. In sandy soils along the sea coast during summer without any adverse effects
Mango, jackfruit, areca nut and other crops and a number of annual crops are commonly grown along the coconut palms in household gardens. Recent studies have shown that under rain fed conditions tuber crops, banana, pineapple, upland rice and pulses can be grown successfully as intercrops in adult coconut plantations without any detrimental effects on the fertility of the soil and the productivity of the palms. Under irrigated conditions cacao forms a very beneficial crop combination with coconut. Other crops suitable for mixed cropping include pepper and tree spices, such as cinnamon, clove, and nutmeg. Mixed farming including the raising of milch animals on fodder grass and legumes raised as intercrops are manured with cow dung and urine. This practice improves the soil fertility by recycling organic wastes, enhances the yield of palms and generates additional income and employment potential for the farmer’s family.
HARVEST AND YIELD. The coconut palm is unique in that once it attains the normal bearing stage, it continues to bear a bunch of nuts in every leaf axils almost at monthly intervals all year round and throughout its life extended over 50 to 60 years. The nuts mature nearly one year after fertilization. Generally, harvesting is done once in 45 to 60 days. Tender nuts in demand as a delicious drink in West Bengal and Maharashtra are best harvested at the age of 6-7months. Large scale harvesting of the tender nuts is not being done in other parts of the country. Nuts for culinary purposes, for making cup copra and good quality fiber are harvested at the age of about 11 months whereas those for ball copra and coarse coir are harvested only when they are fully ripe.
The average yield per hectare varies from 10,000 to 14,000 nuts per annum. From a well-maintained garden an annual yield of 25,000 nuts per hectare can be obtained. Nearly one-third of the annual yield is harvested during the three months– March, April and May–in conditions obtaining on the west coast.
The main product obtained from the coconut is copra or the dried kernel of the nut. Splitting the husked nut into two halves and drying them in the sun prepare the cup copra. After drying for a day or two the kernel gets detached from the shell. The drying is continued for another four to five days. Ball copra is prepared by storing fully ripe nuts for 8-12 months on a raised platform in a shed. They are sometime smoked or heated with a slow fire to accelerate drying. During storage water inside the nuts gets dried up and the kernel gets detached. Nuts are then husked and the shells are carefully broken. The ball copra thus obtained is clean, sweet and highly valued.
The coconut fiber is known as coir. For retting, husks are buried in shallow pits in low-lying areas subject to the tidal flow of backwaters for about 6-12 months. The coir obtained from dry husks would be of inferior quality. it is easier to extract coir from green husks after sufficient retting and the quality of coir is good. The coir is then dried in the sun and spun into coir yarn by hand or with a machine. Coir yarn is used as such or made into ropes, mats, nets, bags etc.
VARIETIES. There are two distinct varieties of coconut the tall and the dwarf. Dwarf x tall and tall x dwarf hybrids have been found to be early bearers and superior to their parents in yield potential under favorable conditions. The tolerance of these hybrids to the root wilt disease adds to their virtue.