Management of Diverse Weed Flora in Widely Spaced Sugarcane Plant Crop in Tropical India Through Sequential and Tank Mix Application of Herbicides

Weed infestation is a serious menace in widely spaced sugarcane, which is gaining popularity in tropical India to facilitate mechanization. Field trials were conducted for two consecutive years to assess the effect of various weed management approaches employing sequential and tank mix application of herbicides (topramezone, tembotrione and halosulfuron methyl) and hand weeding on diverse weed flora, weed control efficiency and yield of sugarcane plant crop. Lowest weed density, weed biomass, highest weed control efficiency and weed control index were observed for three hand weeding at 30, 60 and 90 days after planting (DAP) which was on par with early post-emergence application of metribuzin 1250 g ha⁻¹ at 10 days after planting (DAP) followed by (fb) post emergence application of topramezone 29.4 + atrazine 625 g ha⁻¹ or halosulfuron methyl 67.5 + metribuzin 525 g ha⁻¹ or tembotrione 120 + atrazine 625 g ha⁻¹ at 65 DAP fb hand weeding at 120 DAP. Highest cane yield was obtained with aforementioned treatments and they were significantly superior to unweeded control. The net returns and benefit: cost ratio was also highest with early post-emergence application of metribuzin 1250 g ha⁻¹ at 10 DAP fb post emergence application of topramezone 29.4 + atrazine 625 g ha⁻¹ or halosulfuron methyl 67.5 + metribuzin 525 g ha⁻¹ or tembotrione 120 + atrazine 625 g ha⁻¹ at 65 DAP fb hand weeding at 120 DAP. Topramezone, tembotrione and halosulfuron methyl at the tested dose did not record any phytotoxicity to sugarcane variety Co 86032, which is the ruling variety in tropical India. Sugarcane growers can use these herbicides in rotation along with one hand weeding for efficient and economic weed management.