A field experiment was conducted to study the effect of early post-emergence herbicide namely chlorimuron-ethyl and quizalofop-ethyl on weeds in castor and also to evaluate its weed control efficiency over hand weeding and power operated weeding. It was revealed that pre-emergence application of pendimethalin at 1.0 kg/ha followed by mechanical weeding twice at 20 and 40 DAS has recorded lower weed density with higher weed control efficiency. Mechanical weeding twice, pre-emergence application of pendimethalin followed by chlorimuron-ethyl at 0.01 kg/ha or mechnical weeding twice on 20 and 40 DAS have recorded higher yield and economics. Mechanical weeding twice (2.58 kg/ha), pre emergence application of pendimethalin at 1.0 kg/ha followed by mechanical weeding twice at 20 and 40 DAS (2.57 kg/ha) or post-emergence application of chlorimuron-ethyl at 0.01 kg/ha (2.47 kg/ha) have recorded numerically higher yield and B:C ratio.