Theobroma cacao L. ) is a native of Amazon region of South America. The bulk of it is produced in the tropical areas of the African continent. There are over 20 species in the genus but the cocoa tree Theobroma cacao is the only one cultivated widely.
:: About THE
CROP - COCOA ::
Cocoa being a tropical crop, India offers considerable scope for the development. Cocoa is mainly grown in Kerala, Karnataka, Andhra Pradesh and Tamil Nadu.
Though cocoa has been known as the beverage crop even before tea or coffee, it is relatively a new crop in India. Cocoa being primarily an item of confectionery industries is the produce of Cacao plant mostly grown as a companion crop interspersed within the irrigated Coconut and /or Arecanut gardens. Even though Cocoa comes under the definition of plantation crops pure plantation of cocoa as such is absent in India. The commercial cultivation of cocoa however commenced from 1960’s only. Various Cocoa products are confectionery in nature and consumable with
palatable ness. Internationally it is an item largely consumed in developed countries. India has gained a foreign exchange of nearly Rs. 9.00 crores in 1995-96 and Rs. 6.00 crores in 1996-97 by way of export of cocoa beans and its products from India. At present the global production and consumption of cocoa is around 27.00 lakh MT, compared to this, India’s production is meager
i.e. 10,000 MT.
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.
This is uniformly high in cocoa-growing areas, often 100% at night, falling to 70-80 % by day, sometimes low during the dry season. The most marked effect was on leaf area, plants growing at low humidity ( 50-60%) having larger leaves and greater leaf area than plants growing at medium (70-80%) and high (90-95%) humidity under the latter conditions leaves are small and tend to be curled and withered at the tip. The other effects of humidity concern the spread of fungal diseases and the difficulties of drying and storage.
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 doest not come up in coastal sandy soils where coconut flourish.
Selection of planting material:
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.
Potting mixture and time of sowing:
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.
Method of sowing:
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.
Selection of seedlings for field planting:
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 ‘T’ , inverted ‘T’, 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.
After care :
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.
There are three major varietal groups, namely, Criollo, Forestero and
Trinitario. Among these, Forestero is the one that is commercially grown all over the world. It is high yielding more resistant to pest and diseases and more tolerant to drought compared to
Criollo. Some of the important varieties developed are furnished separately.
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 can be done throughout the year.
Nutrition and irrigation :
Application of organic manures will be useful in the early establishment period. It may not be necessary after about three to five years as cocoa litter will be the rich an abounded source of organic matter. An annual application of 100g N, 40g P2O5 and 140g K2o per plant per year in two equal split doses is recommended. During the first year of planting the plants may be given 1/3rd of the above dose, while the second and third year 2/3rd and full dose of fertilizers applied. While applying manures and fertilizers, care should be taken to open only shallow basins around the plants (radius of 1.5m for adult cocoa) and to avoid serious damage to the surface feeding root systems. The radius of the basins should be proportionately smaller for young cocoa. Providing adequate irrigation helps in increasing the yield by about 30 % both in mono as well as in mixed crop. Irrigation could beneficially be given once in a week in dry months.
Pruning and training:
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.
Rejuvenation of senile gardens:
Top working is a method to convert old poor yielding cocoa plants to high
yielders. This technique helps in the rejuvenation of old and unproductive cocoa plantations. A poor yielding cocoa tree of any age can be converted to a high yielder by the simple procedure of top working. The method is similar to the budding on seedlings. The tree to be top worked is snapped back just below the jorquette (1-1.5 m above the ground) after cutting half way through the width. Patch budding is done on three or four newly formed most vigorous chupon shoots and the rest of the chupons are removed. Budding should be done only when the shoots attain pencil thickness and their leaves are hardened. The bud wood is taken only from fan shoots of high yielding trees. Patch budding can be easily done on these shoots by removing a patch of bark of 2.5 m length and 0.5 cm width and inserting a patch of bud of similar size. This scion is fixed in position and protected by tying with a polythene tape. Three weeks after budding the tape is cut off and the stock portion of the seedling above the bud union is snapped back. The snapped portion is removed only after at least two hardened leaves develop from the bud. When sufficient shoots are hardened the canopy of the mother tree can be totally removed. Top working can be done during all seasons. Still, it may be more convenient if this operation is done in a rain-free period in irrigated gardens. For
rain fed situations, this may preferably be done after the receipt of pre- monsoon showers. Top worked trees grow much faster than budded plants of the same age especially because of the presence of an established root system. They start yielding heavily from the second year onwards while a budded cocoa plant of the same age may take five years for the