Efficacy of selected insecticides against common soybean insect pests
Abstract
This report tackles the question: efficacy of selected insecticides against common
soybean insect pests. In total 8 insecticides; profenofos, dimethoate, chlorpyrifos,
dichlorvos (organophosphates), Acetamiprid, imidacloprid (neonicotinoids), methomyl
(carbamate), and cypermethrin (pyrethroid) were studied against fours soybean insect
pests; whiteflies, pod borers, pod bugs and soybean beetles. A research was carried
out at Makerere University Agricultural Research Institute- Kabanyolo. The experiment
was set in a completely randomized block design with three replications. Results
showed that organophosphates; profenofos followed by dimethoate were superior at
controlling the soybean beetles and also increasing soybean yield. However,
Acetamiprid (neonicotinoid) provided the best control for whiteflies, pod borers, and
pod bugs but the yield was relatively low. Imidacloprid was effective on whiteflies and
pod bugs and wasn't phytotoxic to the soybean. Cypermethrin and chlorpyrifos were
not effective at reducing whitefly population. All selected insecticides provided good
control over the pod bugs and reduced their population as compared to the control.
Although there was a significant difference in the means of the plant parameters; leaf
area, plant height, pod and flower number amongst treatments, this had insignificant
effect on yields. Generally, the total number of insect pests was notably low and
soybean beetles were the most prevalent insect pests followed by whiteflies and lastly
the pod borers and bugs.