Influence of Minimum Insecticide Application on Insect Pest Populations and Yield of Cowpeas in Kumi District
Ohio State University
Makerere University (Uganda)
S. Kyamanywa, A. Ekwamu, J. Karungi (Uganda)
Insect pests are a major constraint to cowpea production in Kumi. To mitigate against the pest problem, many farmers use insecticides, applied up to over 8 times in cowpea growing season (3-4 months). This level of application is not only expensive but also harmful to the user and environment. Hence the need to reduce frequency of application. IPM/CRSP on-farm trials were therefore conducted, to evaluate different spray regimes against the major insect pest of cowpeas. Four spraying schedules were compared against an unsprayed control.
The results indicated spraying at the vegetative stage significantly reduced aphid infestation but had a low marginal return. Single spray at flower initiation, flowering and podding reduced thrips, maruca and pod sucking bugs and had the highest marginal returns. This spray is considered as a minimum insecticide regime for controlling pests of cowpeas in Kumi.