Weed management in cotton based intercropping system under irrigated condition

摘要

Cotton "the king of apparel fibre" is an important commercial textile industry crop. It contributes more than 80 per cent of raw materials to textile industry. Tamil Nadu ranks third in productively with an average cotton yield of 350 kg ha~(-1) against the national average yield of 246 kg ha~(-1). Cotton being a long duration and widely spaced crop, having slow growth rate in the initial stage offers ample scope for raising intercrops. For getting a suitable additional income and nutritional foodto farmer, short duration vegetable crops are intercropped with cotton. Vegetables meet the requirement of farm family and also by raising vegetable as intercrop provide efficient coverage of land resulting reduced weed growth. Other wise interspace remain in between cotton rows encourages severe infestation of weeds. The yield loss varies from 16 to 63 per cent in cotton due to weed infestation (Brat and Brar, 1992). But intercropping system alone is not sufficient to ensure adequate weed control because of varied canopy coverage by intercrops. An integrated approach should be evolved to control the weed through manual and chemical weeding in addition to biological means of intercropping. Hence the present study was carried out to find the effect of weed management practices for sole cotton, cotton + onion, cotton + vegetable cowpea and cotton + lablab systems under irrigated condition. Field experiment was conducted at Agricultural College & Research Institute, Killlikulam, Tamil Nadu, during winterirrigated season. (August 1999 - January 2000) to study the effect of weed management practices for cotton based intercropping system. The experiment was conducted in splitplot design with three replications. The soil of the experimental site was red sandy loam in texture with medium available nitrogen (224 kg ha~(-1)), phosphours (22kg ha~(-1)) and high potassium (448 kg ha~(-1)).