A field experiment was conducted at district sultanpur for two consecutive years (2016-17 and 2017-18) to evaluate the efficacy of Halosulfuron methyl to control the Cyperus rotundus in Maize. The treatments consisted of new herbicide Halosulfuron methyl (75% WG) @ 52.5 and 67.5 g a.i./ha, applied at 5-6 leaf stage of Cyperus rotundus and compared with recommended 2,4-D Ethyl Ester 38% EC (900 g a.i./ha), Atrazine 50% WP (500 g a.i./ha) and two hand weedings at 20 and 35 DAS with untreated control. The results revealed that Halosulfuron methyl 75% WG @ 67.5 g a.i./ha recorded significantly more control of Cyperus rotundus recording 80% and 73% during trials in both years. The significantly higher WCE (at 35 DAS) ranging from 93% and 98% was recorded in Halosulfuron methyl 75% WG @ 67.5 g a.i./ha during both years respectively. The grain yield of maize was also found to be maximum in Halosulfuron methyl @ 67.5 g a.i./ha in both the years, recording 65 and 71 q/ha during both years respectively. Halosulfuron methyl 75% WG @ 67.5 g a.i./ha did not show any residual phytotoxicity on succeeding crop of Rapeseeds. Weed management with weedicides improves soil health compare to weeding by manually.