Cocoa production in Nigeria

Cocoa plant

Cocoa (Theobroma cacao) is a tropical crop that originated from Amazon basin where it was introduced to other countries. Cocoa tree produces pods which contain about 40 seeds or beans inside sweet tasting pulp. The beans are processed mainly into chocolate. Nigeria is ranked the fourth cocoa producing country after Ivory Coast, Ghana and Indonesia (FAO ranking 2005).


Soil requirement and Land preparation
Cocoa does well in a fertile soil with high holding capacity and pH that is close to 6.5. Few trees, especially those which don't harbour pests and diseases must be left on the site to provide shade for young cocoa plants. If possible plant residues should be left to rot on the soil, to protest the soil against erosion and provide humus into the soil.

Raising Seedlings
The seedlings are raised in the nurseries where shade, irrigation and nutrients are provided. The seeds must be collected from ripe cocoa pods and planted immediately to get good germination of at least 90% in two weeks. The seedling stem may grow to 1-2 meters and the bud may have formed 2 to 3 branches before they are transplanted.

Planting
Cocoa seeds can be sown directly in the field, but the best practice is to raise cocoa seedlings in the nursery before they are transplanted. It is better to dig holes a month before seedlings are transplanted. While digging the hole do not mix the soil at the top with the soil below. Heap the soils at different sides so that during planting the soil at the top will be used to fill the hole first.  Plant cocoa at the beginning of raining season, preferably when the soil is moist and the sky is cloudy. When lifting the lifting the seedlings from the nursery be careful not to break the tap root and do not twist it when panting as well. Direct sowing of the seeds in the field is not encouraged because of the requirement for irrigation and difficulty associated with pest and weed management.

Digging of the hole for transplanting

The seedlings can be planted after six months in a field where shade trees have been well established. The shade provides protection against wind, reduces exposure to wind and provides suitable microclimate for the young plants. Shade species which may be permanent or temporary plants and should provide food and income before cocoa trees take over. Examples of shade crops are banana or plantain and pawpaw.

Vegetative propagation can be used to raise cocoa plant where certain characteristics are desired. Vegetatively propagated trees are more uniform and performs better than tree raised from the seed but it requires specialised procedures and techniques in root cutting, budding and grafting.

Plant population depends on the tree vigour, light interception and farming system. Plant spacing of 3.1m by 3.1m is appropriate for good performance and optimum yield.

Fertilizer application
About 200 kg N, 25kg P and 300 kg K per hectare will be needed to grow the trees before they start to produce pods. Significant amounts of Nitrogen, Phosphorus and potassium  are removed from the soil to produce pods, therefore the nutrients should be replaced for subsequent yields. The soil and leaves can be analysed to determined the level of nutrients in the soil and the requirements for fertilizer.

Pruning
Pruning is done to limit the height of the tree, reduce excessive shading and to allow adequate sunlight and increase the yields. Chupons should be continually removed to prevent jorquettes and restrict vertical growths. Fan branches may also  be pruned to prevent low hanging branches. This operation will result in having a tree that is convenient to managed. Vegetative propagated trees have a different structure and will require different management.

Harvesting
There are  two main periods of harvesting cocoa in a year, though harvesting may spread over some months as a result response of flowers to the weather. The pods can be harvested as they become ripe or harvesting can be delayed  two to three weeks when the under-ripe pods are ripe enough to be harvested together. If harvesting is delayed more than necessary the pod may rot and the beans may germinate inside the pods. Harvesting is done by hands with the use of machetes and knives while the harvested pods are cut to extract the beans.

Fermentation and Drying
Fermentation heats up the wet beans as a result of exothermic chemical reaction caused by activity of microorganisms (yeast, acetic and lactic acid bacteria). The process breaks down and drains the muscilage, thus killing the beans within 36-72 hours. Fermentation is done in heaps on the ground or in the baskets covered by plantain leaves usually for 6-7 days. The fermented beans are dried in the sun to 6-7% moisture content for storing and transporting. Dried beans are sorted or sieved to remove damaged beans and plant debris.

Cocoa beans

Cocoa ''Pod index'' expresses the number of pods required to produce 1kg of dried beans. Low pod index means good bean size and weight. ''Recover'' is the proportion of dry fermented beans to wet unfermented beans expressed as a percentage. The percentage ranges from 40% for under-ripe pods to 45% for over-ripe pods depending on the season and variety.

Cocoa beans packed in jute bags

Processing
Cocoa beans are processed in the industries to chocolate and cocoa butter while the shell is removed as a waste product.

Pests and diseases of cocoa are rats, squirrels, wood pecker, insect pests which are mirids or capsids, and cocoa pod borer;  fungi, virus, and mistletoes.