Bioefficacy of halosulfuron-methyl against sedges in bottle gourd

A field experiment was conducted at Bhubaneswar to evaluate the efficacy of halosulfuron-methyl for the control of weeds in bottle gourd. The treatments constituted of new herbicide formulation halosulfuron- methyl (75% WG) in different doses (52.5, 67.5, and 135 g/ha) at 3–4 leaf stages of Cyperus rotundus compared with recommended dose of metribuzin at 490 g/ha and two hand weeding on 20 and 40 DAS with unweeded control. The results revealed that the density of Cyperus rotundus was distinctly controlled by application of halosulfuron-methyl. But grasses and broad-leaved weeds were considerably lower in pre-emergence application of metribuzin at 490 g/ha. The lowest total weed dry weight, higher weed control efficiency and cane yield were recorded in metribuzin 490 g/ha followed by halosulfuron-methyl 135 g/ha. The herbicide tested in this study did not show any residual phytotoxic effect on succeeding crop of cowpea.