Effect of weather parameters on pink bollworm damage and population of predators in Bt cotton in Central India

Study on the seasonal incidence of pink bollworm, Pectinophora gossypiella (Saunders) and population of predators in Bt cotton was carried out under farmers field condition during kharif 2020 and 2021 at Wakhari village (N 19° 51’46.3”, E 76° 10’ 20.9”) of Jalna district (Maharashtra). Squaredamage (per cent) reached its peak in 40^th SMW(7.7)and 36^th SMW(11.5) during 2020 and 2021 respectively. Whereas, green boll damage (per cent) attained peak at 41^st SMW(23.3 ) and 43^rd SMW (25.4) in 2020 and 2021 respectively. Correlation studies revealed significantly negative correlation between RH (Morning, evening and average) and pink bollworm damage. Population of coccinelids and chrysopids showed significantly positive correlation with temperature (T_min and average) and relative humidity (morning, evening and average), while a significantly negative correlation was found between RH and spider population. The study revealed the significant impact of abiotic factors on dynamics of pink bollworm infestation and population of natural enemies in Bt cotton.