Studies on the insect pest management schedule against rainfed cotton varieties

摘要

Cotton is a main source of natural fibre and till today continues to rule as the 'King of apparel fibre'. In the country, rainfed cotton yield is very low due to erratic rainfall, lack of potential genotypes under dryland situation, poor crop and pest management. As many as 200 insect pest have been listed on this crop (Anonymous, 1981) but in rainfed cotton areas of Northern Karnataka, eonomically important sucking pests include leafhopper (Amrasca biguttula biguttula Ishida) and whitefly (Bemesiatabaci Germ.) and among bollworms, American bollworm (Helicoverpa armigera Hubner), spotted bollworm (Earias spp.) and pink bollworm (Pectinophora gossypiella Sound) case extensive damage to the crop. Of the total pesticides applied to the cotton, rainfed cotton which is grown on 70 per cent cotton area (Venugopal et al., 1996) receives only 12 per cent (Ramamoorthy, 1995). This is mainly due to the cost of chemicals and uncertainty of production under rainfed situation. So far very less work has beendone on the evaluation of various integrated pest management (IPM) components viz., use of resistant genotyhpes, parasitoids, HaNPV, botanicals and proper integration of all these efficient bio components along with selective insecticides particularly under rainfed situations. Therefore effort was made to evaluate different IPM schedule in rainfed situation.