A field study was conducted to evaluate the effect of different sowing dates and application of selective pesticides against aphids (Lipaphis erysimi) population in mustard (Brassica juncea). Acephate 50 WG at 700 g. T3 (D3C3) was found to be most effective pesticide to control the mustard aphid population followed by Acetamiprid 20 % SP at 100 g. and Imidacloprid 200 SC at 300 ml. is moderately effective. Application of pesticide significantly controlled the aphid population which suggested that acephate 50 WG at 700 g. could restrain the aphid infestation in mustard. | Effect of different sowing dates and application of selective pesticides against aphids Lipaphis erysimi population in mustard Brassica juncea