IMPACT FROM ORGANIC MANURES AND INORGANIC FERTILIZERS ON THE INCIDENCE OF SUCKING PESTS OF COTTON UNDER RAINFFD CONDITION

摘要

Cotton (Gossypium spp.), considered as 'King of fibre' and 'white gold', is one of the most important commercial crops which is grown in about 80 countries in the world occupying 33 million ha and sharing 44 per cent of the world production in Asia. In India cotton is cultivated over an area of 9 million ha with a production of 146 lakh bales and productivity of 276 kg/ha in 2000-'01 which is very low compared to some of the cotton growing countries and the world average of 590 kg/ha. In Tamil Nadu,cotton occupies a total area of 1.8 lakh ha in which 65 per cent area comes under rainfed condition with a production of 3.4 lakh bales and productivity of 324 kg lint/ha. Despite the recent setbacks, cotton continues to remain the backbone of the ruraleconomy, particularly in the dry land areas. There are number of insect pests attacking cotton. Among the key pests, sucking pests viz., jassids (Amrasca devastans), whiteflies (Bemisia tabaci) aphids (Aphis gossypii) and thrips (Thrips tabaci) are veryimportant since they damage the crop at earlier stage and cause severe yield loss. Organic manuring in pest management is getting its importance in recent past since it is eco-friendly and environmentally safe. Hence, the study was undertaken to evaluate the efficacy of organic manures and inorganic fertilizers on the incidence of sucking pests of cotton.