Residual toxicity of mephosfolan applied @ 1, 2 and 4 μg a.i./ha was studied against nematodes and insects infesting okra, cowpea and tomato crops under field conditions. The toxicity of insecticide was correlated with residues present in soil and plant. In general, mephosfolan was equally effective against nematodes and insects especially at high rates of application. Residues in soil persisted upto 45 days. In Plants, residues persisted beyond 45 days at higher rates of application. However, no residue could be detected in fruits in any of the crop.
