Seasonal and temporal variation in population of mustard aphid, Lipaphis erysimi (Kalt.) on different species of rapeseed-mustard in relation to weather parameters

Abstract

Field experiments were conducted in order to study the seasonal and temporal variation in population of mustard Aphid, Lipaphis erysimi at Norman E. Borlaug Centre of G. B. Pant University of Agriculture and Technology, Pantnagar (India) during Rabi season of 2016-17. Brassica spp. including B. rapa (BSH-1), B. rapa (YST-151), B. carinata (CCN-06-1), B. nigra (PBR-I), B. juncea (Varuna), B. napus (GSC-6) and E. sativa (T-27) were sown on five dates starting from October 3 to December 3, 2016, at fifteen days interval. Early sown crops had significantly lowest numbers of aphids as compared to late sown crops (after 2nd week of october) which had high numbers of aphids. Early sown crops had significantly lowest numbers of aphids as compared to late sown crops (after 2nd week of october) which had high numbers of aphids. it was found that increase in the relative humidity favours aphid multiplication while increase in temperature and rainfall had negative impact on the multiplication of the aphid.