Studies on aphid resurgence and associated biochemical changes in leaves of cotton in response to pyrethroid applications

A field experiment was conducted in a split plot design to study the influence of three pyrethroids sprayed 50, 65 and 80 days after sowing on the biochemical parameters of three varieties of cotton and its relation to the resurgence of aphid. In all the varieties, application of pyrethroids induced greater accumulation of total sugar, protein and depletion of phenol associated with high percent of aphid resurgence. Deltamethrin treatment of LRA 5166 and SAVITA and Cypermethrin treatment on MCU 5 showed high aphid population, high total sugar and protein with low phenol content. Repeated spraying of pyrethroids enhanced the quantity of total sugar and protein in the leaf samples.