Present field studies were conducted during the Rabi season of year 2015-16 at Regional Research Station, Rohtak (Haryana), India, to assess the yield losses due to mustard aphid in various Brassica spp. (B. juncea, and B. rapa) sown under early and late sown conditions. The avoidable losses in terms of seed yield varied from to per cent, found lowest () in HNS 0901 whereas, highest () in BSH 1 under timely sown conditions. These losses ranged from to per cent under late sown conditions, found lowest () in HNS 0901 although highest () in BSH 1. The avoidable oil content losses in all three Brassica spp. were ranged from to per cent, found lowest () in RH 0749 however, highest () in BSH 1 under timely sown conditions. These losses in oil content varied from to per cent, found lowest () in RH 0749 however, highest () in BSH 1 under late sown conditions. Germination percentage was not significantly affected by the mustard aphid in all three Brassica species. | Assessment of avoidable yield losses due to Lipaphis erysimi kalt in various Brassica spp.
