An Experimental Study of Cotton Seed Treatment By Certain Neonicotinoid Insecticides Against the Incidence of Early Infestation of Bollworms, Their Effect on Growth and Lint Yield Characteristics of Cotton Plants - CANCELED

The Field study was conducted to experimental study the efficacy of two neonicotinoid insecticides (imidacloprid and thiamethoxam) as seed dressing and seedling bed at the 3^rd true leaf emergence, against two of the common injurious bollworms of cotton in Egypt: the spiny bollworm (SBW) and the American bollworm (ABW). Reduction in the infestation and larval content/100 green bolls and/or plants of both pests was determined up to 90 days of germination. The results showed that imidacloprid and thiamethoxam caused a significant larval reduction (79.9, 75.5% and 66.9, 72.7%) of the SBW cotton bollworm in the both season, respectively, at early infestation after 90 days of germination. Whereas imidacloprid and thiamethoxam recorded a gradual reduction (80.9, 70.8 % and 79.5, 70.8) in the ABW cotton bollworm in the both season, respectively, after 90 days of germination. Most interestingly, the present results indicated that application of imidacloprid and thiamethoxam as seed treatments significantly increased the total chlorophyll content in cotton leaves that enhance plant growth and improve cotton yield. It is also observed that both insecticides promoted early appearance of cotton squares and improved in the cotton fiber properties. In general, the selection of a suitable insecticide for controlling the cotton bollworms not only depends on its efficacy against the insects but also on their profitable effects on cotton production and fiber quality.