Determination of action threshold based on pod phenology for cocoa pod borer management

Abstract

In Integrated Pest Management (IPM), decision making is necessary. Many decisions making being developed for the IPM programme its action threshold were based on the damage by the pest or the number of pest on the crop. However, on cocoa such a method to call for pest intervention was often too late, thus great damage have been occurred to the pods. Therefore, by using the pod phenology to be incorporated in the decision making is crucial. In this study, the length and diameter of the cocoa pod on three clones, BR 25, DESA 1 and PBC 123 were measured. Pareto analysis was used to determine the pod phenology which is very critical to CPB infestation. It was found that in this study the action threshold to initiate the CPB control should be at pod size range 80-120 mm in length or 40-60 mm in diameters. On the period of the study, by considering both length and diameters of the pod, chemical insecticide should be initiated when 80% of the pods on the tree are in that particular size range. Chemical control of CPB at that critical pod phenology will save 80% of the cocoa pod from heavy infestation by CPB.