Bio-efficacy of different insecticides against major insect pests of high density planting system (HDPS) cotton with canopy manipulation

A field study was carried out to evaluate the efficacy of insecticides and canopy manipulation for managing insect pests in Bt cotton under HDPS. Canopy management moderately reduced sucking pest infestation and larval population of pink bollworm (Pectinophora gossypiella). Aphid population showed significant negative correlations with maximum and minimum temperatures and relative humidity. Jassid population showed positive correlations with minimum temperature and evening relative humidity, while thrips showed significant positive correlations with minimum temperature, evening relative humidity, and rainfall. Whiteflies correlated significantly with maximum temperature. Pink bollworm larvae showed negative correlations with evening relative humidity and wind speed. Spinetoram 11.7% SC was most effective against pink bollworm and thrips, and Flonicamid 50% WG best suppressed sucking pests, followed by Tolfenpyrad 15% EC and Acephate 75% SP. Canopy management slightly reduced Chrysopa abundance and improved compatibility of Spinetoram and Flonicamid with natural enemies. Seed cotton yield was highest under HDPS + canopy management + Spinetoram 11.7% SC (17.11 q/ha).