Quantification of avoidable yield losses in oilseed Brassica caused by insect pests

摘要

A six year field study was conducted from 2001 2002 to 2006 2007 at PunjabAgricultural University, Ludhiana, India to study the losses in seed yield ofdifferent Brassica species (B. juncea, B. napus, B. carinata, B. rapa and Erucasativa) by the infestation of insect pests. The experiment was conducted in twodifferent sets viz. protected/sprayed and unprotected, in a randomized blockdesign, with three replications. Data on the infestation of insect pests, andseed yield were recorded at weekly intervals and at harvest, respectively. Theloss in seed yield, due to mustard aphid and cabbage caterpillar, varied from6.5 to 26.4 per cent. E. sativa suffered the least loss in seed yield andharboured the minimum population of mustard aphid (2.1 aphids/plant) andcabbage caterpillar (2.4 larvae/plant). On the other hand, B. carinata washighly susceptible to the cabbage caterpillar (26.2 larvae/plant) and sufferedthe maximum yield loss (26.4%).