Field and Semi-Field Trials for Evaluating the Efficiency of Certain Pesticides Against Some Cotton Pests (Minia University - Egypt)

In 2011 cotton season, different pesticides were evaluated against some key pests of cotton in egypt.  Imidaclopride and thiamethoxam were tested as seed treatment againdt cotton aphide infested cotton seedling.  Imidaclopride (7mg per kg) was more effective than thiamethoxam (2gm per kg seeds) in protecting cotton seedling against aphid.  However, predators were significantly reduced in imidaclopride treatment.  Of 4 insecticide tretments, 4 pesticides were evaluated against cotton leaf worm, Spodopter littoralis.  Carbosulfan and gamma-cyhalothrin were less effective against the 4 th instar larvae of cotton leaf worm.  The chitin synthetic inhibitor, lefenuron and the OP inseticide, profenofos were effective against all tested instars and maintined their efficiancy in the field for 10 days after treatment.  Two formulations of lambada-cyhalothrin and zeta-cypermethrin were tested against bollworms and alll were efective without significant difference between them in this respect.  They gave more than 80% reduction in bollworm larval content.