Persistence of toxicity of some insecticides in dust and wettable forms against mustard aphid, Lipaphis erysimi (kalt)

Abstract

An experiment was laid out with 12 treatments including control to find out the persistence of toxicity of insecticides in dust and wettable formulations at their recommended concentrations during winter season on mustard crop. The residual effectiveness was worked out in the laboratory by observing mortality on the treated apical growth parts of mustard plant of each treatment after 24 hrs, 5 and 10 days of insecticidal applications and in the field by taking observations on aphid population. Both under field and laboratory conditions, fenitrothion 0.1% spray and phenthoate 2% dust proved most effective. Carbaryl 0.1% spray proved ineffective. After 10 days of treatment all insecticides of dust and wettable formulations last their toxicity.