Average rainfall of 1250-3000 mm. per annum and preferably between 1500-2000mm. with a dry season of not more than 3 months with less than 100mm. rain per month is ideal, but the quantity is less important than distribution. Rainfall can be supplemented with irrigation during dry months.
Temperature varying between 30-320C mean maximum and 18-210C mean minimum but around 250C is considered to be a favourable. It can�t be grown commercially in areas where the minimum temperature fall below 100C and annual average temperature is less than 210C
Cocoa is grown on a wide range of soil types and the standards for soil suitable for cocoa vary considerably. Cocoa trees are more sensitive to moisture stress than other tropical crops. In addition cocoa trees are sensitive to water logging. While they can withstand flooding, they will not tolerate stagnant, water logged conditions. The depth of the soil should be at least 1.5m. The best soil for cocoa is forest soil rich in humus. The soil should be such as allowing easy penetration of roots capable of retaining moisture during summer and allowing circulation of air and moisture. Clay loams and sandy loams are suitable. Shallow soils should be avoided. A minimum requirement of 3.5% organic matter say 2% Carbon in the top 15cm. is ideal for growing cocoa plantation. Cocoa is grown on soils with a wide range of PH from 6-7.5 where major nutrients and trace elements will be available. Cocoa does not come up in coastal sandy soils where coconut flourish.
Cocoa can be propagated through seeds or by vegetative means. For raising seedlings, seeds of mature pods are taken from high yielding mother plants. The mother plants selected should yield more than 100 pods per year and should have medium or large green pods with an average dry bean weight of not less than one gram. A more suitable procedure for planting good quality seedling will be to collect hybrid seeds from bi clonal or polyclonal seed gardens involving superior self- incompatible parents. The seeds generally lose their viability after seven days of harvest. To avoid these drop in viability during long periods of storage, the extracted seeds may be stored in moist charcoal and then packed in polythene bags.
The normal potting mixture with farm yard manure, sand and soil in equal proportions is good for raising cocoa seedlings. Though cocoa seeds germinate at any time of the year, the best period of sowing the seeds in nursery is December- January so that four to six months old seedlings will become available for field planting by the onset of the monsoon in the traditional areas.
The seeds are to be sown with the helium end facing downwards or are sown flat. The seeds should not be placed too deep in the soil. The seeds start germinating in a week's time but the process may continue for another week. Generally 90% of the seeds germinate. Regular watering is essential to keep the soil moist. Over watering should be avoided in order to check the outbreaks of diseases.
Four to six months old seedlings are generally used for field planting. Since seedling vigour and final yield are closely related, the seedlings for field planting should be selected based on seedling vigour. Seedling vigour can be estimated based on height of seedlings and stem girth.
Vegetative propagation: Large scale production of superior planting material is possible in cocoa through vegetative means like budding and grafting of which budding is the easiest. The different budding methods feasible are patch and modified Forkert. The new method of micro budding also may be followed. Selection of root stocks and bud wood: Seedlings of about 60-90 days are generally used as root stock. While selecting root stock, care should be taken to see that both root stock and scion are of same thickness and physiological age. Bud wood from chupons can be taken for budding. The patch to be taken should be above 2.5 cm. long and 0.5cm. wide with a single vigorous bud on it. Bark of the same size is removed from the root stock and the bud patch is inserted. It is then tied with grafting tape. The patch selected should have bud that is visible to the naked eye but it should not have signs of proliferation. Even though bud wood freshly collected can be used for budding, pre-curing of bud wood is found to increase the percentage of success. Such a pre-curing consists of removing the lamina portions of all the leaves from the region of bud stick chosen. The petiole stump will fall off in about 10 days and the buds would have been initiated to grow. Buds may now be extracted from the pre-cured portion. If the root stocks are less than four months old, the bud wood selected should also be green or greenish brown.
About three weeks after budding, the grafting tape is removed. If there is successful bud union, a vertical cut is made half way through the stem above the bud and the stock portion is snapped back. Such snapped root stock portion is cut and removed only after the bud has grown sufficiently with at least two leaves hardened. After about four to six months, they are ready for field planting. Care should be taken to remove the new sprouts from the root stock portion.
Cocoa needs shade for its natural habitat young cocoa plants grow best with 50% full sunlight. As the tree grows, its shade requirement is reduced.
Cocoa is planted as a pure, mixed crop or intercrop. When planted as a pure crop, Dadap (Erythnina lithosperma) is planted at 3x 3m spacing to provide shade. Dadap needs pruning every year. For more permanent shade, Albizzia stipulate can be planted adopting 9x9 or 12x12m spacings. This requires 4 to 6 years to develop proper canopy to provide sufficient shade. Protection from north east winds by planting wind-breaks is also necessary. Cocoa can be planted as intercrop in coconut gardens provided the spacing of coconut is sufficient to provide enough shade and the soil is suited to cocoa. In arecanut gardens too, cocoa can be planted as intercrop. The spacing of arecanut should not be less than 2.7 x 2.7 m. The planting hole should be at least the same size as to hold the basket or polythene bag in which seedlings are raised. Planting should coincide with the onset of monsoon but in places where irrigation facilities are available planting cocoa can be done throughout the year.
Pruning is an important continuous operation in cocoa. Cocoa grows in a series of stories. The chupon or vertical branch of the seedlings terminates at the jorquette when four or five branches develop. Further chupon develops just below the jorquette and continues its vertical growth till another jorquette develops and so on. When the first jorquette develops at a height of 1.5m, the canopy will form at a height convenient for harvesting and other operations. It is desirable to limit the tree at that level by periodical removal of chupon growth. The second jorquette may be allowed to form if so desired. Operations like harvesting, spraying etc. will be easier if the height of the trees is kept at the second story level. Generally three to five branches develop at each jorquette. When more fan branches develop one or two weaker ones have to be removed. Similarly overlapping branches are also have to be removed for facilitating uniform light; penetration of every part of canopy Where the climate and soil allow a continuous growth cocoa trees will form a jorquette within 6-9 months of planting, the canopies will meet at a spacing of 3 x 3m within 18 months and the 1st crop may be obtained towards the end of 2nd year or in 3rd year.
The development of the pod takes 5-6 months from fertilizing the flower to full ripening. Harvesting involves removing the ripe pods from the trees and opening them to extract the wet beans. As they ripen, the pods change colours, green pods becoming orange, yellow and red pods turning orange. Each pod will have 25-45 beans embedded in white pulp ( Mucilage). Generally cocoa gives two main crops in a year during September � January and April-June, though off-season crops may be seen almost all through the year especially under irrigated condition.
Only ripe pods have to be harvested without damaging the flower cushions by cutting the stalk with the help of knife. The harvesting is to be done at regular intervals of 10-15 days. The damaged , unripe and infested pods have to be separated out to ensure better quality of beans after processing. The harvested pods should be kept for minimum period of two days before opening for fermentation. However, pod should not be kept beyond four days.
Curing is the process by which cocoa beans are prepared for the market which requires beans of good flavour, potential and good keeping qualities. The curing process involves fermentation followed by drying. Fermentation involves keeping the mass of cocoa beans well insulated so that heat is retained, while at the same time air is allowed to pass through the mass. The process lasts up to 7 days and followed immediately by drying. Cocoa bean mass under the process of fermentation has to be overturned regularly to maintain the uniform specified temperature all over the mass.
1.Fermentation 2.Heap Method 3.Tray Method 4.Box Method 5.Drying & Storage
Fermentation of Cocoa beans is essential to remove the mucilaginous pulp, to develop flavour and aroma precursors, reduce bitterness, kill the germ of the seed and to loosen the testa. Among the various methods adopted for fermentation in different cocoa producing countries, Heap, Box Tray and Basket methods are considered as the standard methods.
This method involves keeping a mass of not less than 50 kg. of wet beans over a layer of banana leaves. The banana leaves are spread over a few sticks to keep them a little raised over the ground level to facilitate the flow of sweating. The leaves are folded and kept over a heap of beans and a few wooden pieces kept over it to keep the leaves in position. The heaps are dismantled and the beans mixed the third and fifth days. It needs about six days for the completion of fermentation and the beans can be taken out for drying on the seventh day.
Even though the minimum quantity of beans required for effective fermentation is 50 kg. a further increase in quantity of beans in a heap will be beneficial. However, heaps of more than about 500 kg. may be difficult to handle.
Wooden trays of size 90 cm x 60 cm x 13 cm with battens or reapers fixed at the bottom with gaps in between, are filled with beans. Each tray can contain about 45 kg. wet beans. Six such trays are stacked one over the other and an empty tray is kept at the bottom to allow for drainage of sweating. After stacking, the beans of the top most tray are kept covered with banana leaves. After 24 hours of setting the stack of trays is kept covered with gunny sacking to conserve the heat that develops. There is no need for mixing the beans and fermentation will be completed in four days. On the fifth day the beans can be taken out for drying.
The minimum number of trays required to be stacked is about six but as many as 12 trays can be used simultaneously.
Wooden boxes of 1.2 x 0.95 m x 0.75 m with holes at the bottom and sides of the box are filled with wet beans. These boxes can hold one M.T. of wet beans. The beans are to be mixed on alternate days. As the quantity of beans is high, this is best done by changing the beans from one box to another at the time of mixing. This would necessitate having a minimum of three boxes.
Wet beans taken for fermentation should be sufficiently ripe so as to separate the beans form the polacuta and husk easily. Minimum quantity of wet beans for a normal fermentation is about 100 kg. The duration of fermentation is commonly for 3-5 days i.e., 72-120 hrs. Fermentation over 120 hours will cause loss of chocolate flavour and development of off flavour.
The fermented beans can be dried either in the sun or by artificial means. Sun drying can be done in thin layers of 2 - 3 cm. depth and stirring from time to time. When the beans are dried properly, they produce a characteristic cracking sound on compressing a fistful of beans in the palm. The more scientific method is to use moisture meter. The dried beans after cooling maintaining 6 -8% moisture should be cleared before storage. The fruit broken, shriveled and other extraneous material are removed. The cleared bags are kept on a raised platform of wooden planks.
There are three main kinds of cocoa trees grown throughout the world, each with their own flavor profiles and growth characteristics. There also are hundreds and hundreds of different hybrids.