Importance
A healthy cocoa tree produces at least 25 pods per year which provides approximately 1 kg of dry cocoa. Yields per tree in a year can be classified as:
◦ Good (25 or more pods)
◦ Average (15-24 pods)
◦ Poor (14 or less pods) ◦
Farmers who have unproductive trees (producing 10 or less pods per year) should think about what they can do to improve their productivity. There are options for where to plant or replant cocoa. These include:
• Under-planting: planting new cocoa trees in an existing farm, re- moving some but not all cocoa trees
• Gradual replanting: removing all cocoa trees in a section or block of an existing farm and planting new cocoa trees in that section
• Complete replanting (re-establishment): removing all cocoa trees and completely replanting the whole field
• New planting (establishment): Planting cocoa on fallow land or an area where cocoa has not been planted before
Regardless of which option a farmer chooses, it is important to plant improved cocoa planting materials (hybrids) from approved sources in order to get high and reliable yields.
Underplanting
This method of planting is best when trees are old (over 30 years). Cocoa trees left in the field provide shade to the newly planted trees. This method is not recommended where cocoa swollen shoot virus is a problem.
Method: Identify diseased/old and unproductive cocoa trees based on annual yields (see the exercise »Deciding which cocoa trees to rehabilitate or eliminate«). Survey the farm, looking for large open areas where there are no cocoa trees. Remove diseased/old/unproductive trees and plant new improved cocoa planting material. Where gaps are large and there is not enough shade, plant food crops before or at the same time as the cocoa seedlings.
Advantages: farmers still get income from existing trees; old tree stock provides initial shade for the newly planted trees; it does not require additional land area, less expensive than other methods.
Disadvantages: possibility of old diseased trees infecting the newly planted trees; damage to young trees when removing old trees.
Complete replanting
This is best applied when most trees on the farm are unproductive due to old age, disease and pest and there is not much the farmer can do to make the farm more productive.
Method: Cut down all the trees on the farm including shade trees that are not compatible with cocoa. To avoid spreading of cocoa swollen shoot virus and to improve soil fertility, leave the area fallow for at least 3 years before replanting cocoa. In such situation, farmers may improve soil conditions and increase organic matter in the first year by preserving and/or planting timber trees (e.g., Terminalia sp. Khaya sp etc) and nitrogen fixing trees (Gliricidia sp.) at 12 x 12 m triangular spacing. In March of the third year, thin the fallow and plant food crops at 3 x 3 m. Plant cocoa at the same spacing in May, when the rains have stabilized.
Advantage: Where swollen shoot disease is prevalent, complete replanting disrupts the cycle of disease transmission by preventing old trees from reinfesting the new ones.
Disadvantage: it is costly and requires a lot of labour, loss of income from cocoa
Where to plant cocoa
Importance
Farmers need to consider several factors before planting cocoa in a new area to make sure that they make the best use of land, labour and inputs in order to get the highest production. Factors to consider include:
• Climate
• Soil fertility
• Type of vegetation
• Source of improved planting material
Climate
Cocoa needs a high amount of rainfall: 1,250 – 3000 mm per year. It grows best in areas where the dry season does not last for more than three months. Cocoa grows best in warm temperatures: between a high of 3032oC and a low of 18-21 o C.
Soil fertility
Because cocoa is a forest crop suited to forest soils, it is exceptionally demanding in its soil requirements. Most tropical forest soils consist of accumulated plant nutrients in the top few centimeters. When forests are cleared, the nutrients are rapidly released, giving the soil a high fertility for a few years.
Hence, when planting cocoa in a field that has been used to grow other crops, farmers should remember to apply recommended mineral fertilizer or compost to the planting hole to improve soil fertility.
Not all soils are suitable for cocoa cultivation. Cocoa trees grow well only in good quality soil. It is therefore important to select an appropriate site before establishing a cocoa farm. To select a site look for the presence of earthworms in the soil since this gives an indication for humus soils. After the inspection for earthworm and humus, conduct a careful analysis of the soil in order to characterize the soil.
Vegetation
Cocoa is an understorey crop which means it grows well under shade. Cocoa trees need enough vegetation cover for two purposes:
• To provide adequate initial (0-3 years) and permanent (after 4 years) shade and organic matter.
• To improve soil fertility
When clearing a field to grow cocoa, farmers should leave forest trees and other vegetation that grows well in association with cocoa and which have economic or household value. In areas where there are no forest trees, farmers should plant forest trees (e.g., Terminalia sp., Milicia excelsa, Khaya ivorensis, etc.) and traditional agroforestry tree species that can fix nitrogen (e.g. Gliricidia sp., Albizia sp., Acacia sp., etc.) to improve soil nutrient content.
When establishing a new cocoa farm, farmers should also plant certain recommended food crops such as plantain, cassava, coco yam, maize, etc., to provide initial shade for newly planted cocoa seedlings and also serve as source of income. In selecting which crops to plant, it is important to choose varieties that provide maximum shade. When an effective initial shade is provided for newly planted cocoa seedlings it protects the seedlings from intense sun light and Mirid attack.
Preparing to establish cocoa in a new field
Importance
In order to establish cocoa farms, most farmers clear and/or burn existing forest, and in the process either thin or completely eliminate the over-story trees to make growing space for their cocoa and food crops. Most farmers who establish their farms this way often do not follow the appropriate recommended planting arrangements of the different components of plants per unit area. As a result, it limits the yield potential of the various crops, especially cocoa.
Hence, before planting cocoa in the field the following activities should to be carried out properly:
•Land preparation
• Lining and pegging
• Spacing
• Planting temporary shade
• Shade management
Land preparation
Cocoa can be planted on fallow land or land occupied by other food and tree crops. Where farmers use fallow areas, the underneath vegetation should be cleared at the end of the wet season or as soon as the dry season starts. This initial clearing makes it easy to fell undesirable trees before cocoa is planted. The resulting debris (biomass) can be burned or left to rot.
Burning however can destroy a great deal of potential humus in the soil since it results in the release of large amounts of ash causing imbalance of nutrients in the soil. It also exposes the soil to erosion, which can lead to losses of organic matter. In many situations burning causes the invasion of some obnoxious weeds like Imperata cylindrical and Chromolaena odorata, which negatively affect the productivity of the land.
Farmers can do selective burning (i.e., burn in small heaps) or avoid burning completely and manage the debris (biomass), after most of the big trees have been cut into pieces and carried away as fire wood, by leaving it to rot in the soil and thereby adding organic matter to improve the soil.
Lining and pegging
Lining and pegging at the recommended spacing will give more income on cocoa yield per unit area. To do Lining and pegging on a field, place a peg at a reference point and with a rope tied to the peg make a horizontal base line to the edge of the land, about 100 m. From this peg, and on the
20
horizontal base line, mark the recommended spacing for each crop to be planted and put a peg at every mark. Repeat the process vertically till the whole farm is pegged.
Spacing
Every country has adopted a recommended spacing regime for planting food crops, fruit and timber trees. These recommendations are related to the climate, type of planting material, shade conditions and soil type. In Ghana for instance, recommended spacing for planting hybrid cocoa seeds and plantain is 3 x 3 m resulting in 1111 cocoa trees and 1111 plantain per hectare. Spacing affects the shade conditions on cocoa farms. Spacing also plays a role on certain diseases (Black Pod) and pests (Mirid) in cocoa.
For instance, when seedlings are widely spaced and there are gaps in the canopy, there is a higher chance of Mirid attacks on trees. Black pod is more likely to develop when cocoa trees are closely spaced resulting in high humidity under the dense canopy.
Shade management
Cocoa needs a well established shade level at all stages of its production cycle (young, mature and old) to protect it against:
•Pests
• Diseases
• Drying out
