Efficacy,persistence and removal of chlorpyrifos-methyl after application against cotton leaf worm in soybean

Soybean crop (glycine max l) is a very important economic crop belongs to leguminosae,considered one of the high potentially protein source and attacked by cotton leaf worm spodoptera littoralis (boisd),the major pest thought-out the growing season. therefore,this study aimed to evaluate the insecticidal activity of chlorpyrifos-methyl against the cotton leaf worm spodoptera littoralis on soybean (giza 21). furthermore,to investigate the persistence of this tested insecticide after application under some of the environmental factors (direct sunlight,ultraviolet rays and temperature). moreover,to evaluate the effect of some commercial processes on the safe removal of chlorpyrifos-methyl residues from soybean seeds. the results showed that chlorpyrifos-methyl was effective against cotton leaf worm. the exposure of chlorpyrifos-methyl to the direct sunlight,ultraviolet rays and different temperature degrees significantly reduced its level. cooking procedure showed higher effect than dry heating at (90-95°c) on removal of tested insecticide from soybean seeds. the results showed that the food processing is an important way for minimizing chlorpyrifos-methyl in the final products lower than the maximum residue limits.