METHODS OF CONTROLLING BLACK‐POD DISEASE (CAUSED BY PHYTOPHTHORA PALMIVORA) OF THEOBROMA CACAO IN NIGERIA

Supplementary methods of controlling black‐pod disease (Phytophthora palmivora) of cocoa in Nigeria are considered, because fungicide application is not always economic. There is no evidence that resistance occurs within the local population of Amelonado‐type trees. Although the percentage of diseased pods was greater with trees closely spaced (5 times 5 ft. to 8 times 8 ft.), than with widely spaced trees (10 times 10 ft. to 15 times 15 ft.), the closer spacings often gave more healthy pods per acre. Loss of pods from black‐pod was decreased when trees were inspected frequently (alternate days) and infected pods were removed when showing the earliest symptoms. However, this procedure may not be economic, except when potential yields are relatively small (fewer than twelve pods per tree). Satisfactory control of black‐pod was obtained with copper fungicides, applied with either hand‐sprayers or a power‐sprayer. The monetary return depends on yield level, rather than on disease incidence or on spraying costs. It is recommended that spraying should be practised when the potential yield is twelve or more pods per tree.