Bioefficacy of new formulation of pesticides against pink bollworm (Pectinophora gossypiella (Saunders)) on cotton and their safety to natural enemies.

摘要

The relative efficacy of a new formulation of lambda -cyhalothrin 5 CS along with thiodicarb 75 WP and profenofos 50 EC against pink bollworm (P. gossypiella) and their influence on natural enemies (predators and parasitoids) and cotton hybrid NHH-44 were investigated in 2005. The applications of lambda -cyhalothrin 5 CS at 12.5, 15, 25, and 50 g a.i./ha, lambda -cyhalothrin 5 EC at 25 g a.i./ha, thiodicarb 75 WP at 750 g a.i./ha and profenofos 50 EC at 500 g a.i./ha were given at 15 days interval. The treatment with 5 CS at 50 g/ha recorded the highest seed cotton yield of 2276 kg/ha, which was at par with lambda -cyhalothrin 5 CS at 25 g a.i./ha (2118 kg/ha). Among the evaluated doses of lambda -cyhalothrin 5 CS formulation, the 50 g a.i./ha proved to be the most effective against pink bollworm by recording the least damage to squares, flowers, green bolls, loculi, open bolls and locules. The treatments with lambda -cyhalothrin 5 CS at 25 g a.i./ha, lambda -cyhalothrin 5 EC at 25 g a.i./ha, thiodicarb 75 WP at 750 g a.i./ha and profenofos 50 EC at 500 g a.i./ha were also found effective against the pink bollworm. These insecticides were also safe to the natural enemies.