Impact of abamectin on bollworm complex in cotton

Field trials were conducted at the Indian Agricultural Research Institute, New Delhi, during kharif seasons of 2002–03 and 2003–04 with American cotton (Gossypium hirsutum L. var. Pusa 8–6), to evaluate the bioefficacy of abamectin 1.8% EC against bollworm complex (Earias vittella, Helicoverpa armigera and Pectinophora gossypiella). All the four doses of abamectin (8.1, 10.8, 14.5, 18.5, 22.5g ai/ha) and Vertimec (14.5g ai/ha) were significantly effective in suppressing bollworms incidence and increasing the yield of seed cotton over control, whereas its lower dose 8.1g ai/ha did not differ significantly from control. Maximum yield of seed cotton (1811.1, 2052.2 kg/ha) was recorded from plots treated with insecticidal treatment T5, abamectin 22.5g ai/ha, followed by its lower dose 18.5g ai/ha (1657.3, 1605.2 kg/ha), whereas in control the yield was less (676.7, 796.3 kg/ha) during crop season of 2003 and 2004 respectively. The potentiality of abamectin would fit in very well towards the development of specific strategies and tactics for the management of bollworm complex with the novel molecules as an alternative to synthetic insecticides.