Bio-efficacy of various chemical insecticides against APHID (Aphis gossypii glover) of “GCH-6” cotton (Gossypium hirsutum L)*

An experiment was conducted during 1999–2000 to study the bio-efficacy of various chemical insecticides against aphid of “GCH-6” cotton (Gossypium hirsutum L) and their effect on ICBR. The results of eleven different insecticidal treatments showed that the treatments with imidacloprid 0.006 per cent, monocrotophos 0.04 per cent. endosulfan 0.07 per cent, dimethoate 0.03 per cent and methyl-o-demeton 0.025 per cent were found most effective for the control of A. gossypii on cotton under field condition. The maximum yield of seedcotton was recorded from the plots treated with endosulfan 0.07 per cent (1549 kg/hal. Treatment with monocrotophos 0.04 per cent was found most economical as it gave the highest cost benefit ratio (1 15.45) followed by methyl-o-demeton 0.025 per cent (1: 14.42), dimethoate 0.03 per cent (1: 14.39), phosphamidon 0.03 per cent (1: 13.73) and endosulfan 0.07 per cent (1: 11.14).