Cocoa pests and diseases and their control within MACEFCOOP

Cocoa is very susceptible to attack by insect pests and fungal diseases. Cocoa capsids (also called mirids), which are sap-feeding insects, can destroy developing shoots and leaves. Severe attack may cause defoliation and subsequent low yields. Attacks are more serious where shade is reduced, so may occur after the death or felling of a forest tree. Although developing pods (cherelles) may be damaged, capsids do not generally cause serious damage to pods in West Africa. The situation is different in other locations, for example in South and Central America and Papua New Guinea where pod feeding by capsids causes serious crop loss.

Black pod, caused by fungi of the Phytophthora genus, is a very serious disease that attacks, principally, cocoa pods.
Cocoa pods affected by black pod disease.

an average of six capsids per ten trees are capable of causing very serious injury. They are sucking insects and they damage the soft young tissues of the tree by piercing the young shoots with their mouth parts, injecting poisonous saliva and then sucking liquid food out of the resulting wound.

Mirids can kill only young green shoots and such damage is restricted to periods of flush when this type of tissue is present. Young cocoa is particularly susceptible to mirid attack. Thus, capsids make cocoa difficult to establish and can delay the time for it to come into bearing by several years.

Black pod

The spread and level of infection by Black Pod is influenced by climatic conditions and the rainfall pattern in Cameroon makes Black Pod (Phytophthora Pod Rot) a serious problem.

Until comparatively recently it was believed the causal pathogen of Black Pod was Phytophthora palmivora. Research has shown that phytophthora megakayrya is the main pathogen in Cameroon.

Black pod attacks all parts of the cocoa plant but is most damaging on the pods because the beans can be damaged and therefore yields reduced. Systemic fungicides have been developed and these can be very effective in reducing the incidence of the disease but these products are expensive.

Less expensive Copper fungicides can be used but they are less effective, need frequent reapplication because they have a protectant action on the surface of the developing pods.

If MACEFCOOP were to consider production of organically certified cocoa, the only permitted fungicide would be an inorganic copper formulation.

Pest and disease control

Pest and disease control is an important component of the MACEFCOOP cocoa production programme and an effective training regime has been put in place, aided by the REMA project that has funded the appointment of an Agricultural Officer and the establishment of the training programme and external workshops.

The campaign against capsids, when conducted on a routine basis, involves 4 applications per season. MACEFCOOP farmers are gradually adopting systems that involve treatments only when attacks are noted. This prevents the application of any unnecessary treatments.

MACEFCOOP management purchases approved pesticides in bulk quantities and sells to members at cost price, which is considerably lower than the prices charged by small suppliers in Mamfé or the villages. It also ensures that only approved chemicals are used.

Distribution of cost-price chemicals is useful: we can spray our produce to improve the quality; we can now fight blackpod disease; and we get higher yields. However, we would also like MACEFCOOP to supply us with spraying equipment.
a member of Akwaya Section, MACEFCOOP