Pesticide Research Journal

Application of pyrethroids has been found to induce high aphid population in the order of deltamethrin, cypermethrin and fenvalerate respectively in cotton. High accumulation of total sugar and low level of phenol were observed in the pyrethroid treated leaf samples. The variety LRA 5166 and SAVITA responded to deltamethrin with high aphid population associated with high sugar and low level of phenol content. Similar results were observed in the variety MCU 5 with reference to cypermethrin. The activity of the en2ymes peroxidase (PO) and poly phenol oxidase (PPO) was more in pyrethroid treated leaf samples whereas low level of phenyl alanine ammonialyase (PAL) recorded in pyrethroid treated leaf samples reduced trans cinnamic acid content which in turn led to resurgence of the sucking pest Aphis gossypii G.