Bio-efficacy of herbicides applied at the 2 to 4 leaf stage of weeds in sugarcane after second interculture

A field experiment was conducted during 2006–2008 to find out suitable dose of velper K4 60 WP for the control of weeds in spring planted sugarcane. Weed population and weed dry weight were reduced significantly due to different weed control measures. Cane yield increased significantly with all the measures over weedy check and was highest under weed free conditions (94.3 t/ha) though it was at par with hoeing at 30, 60 and 90 day after transplanting (DAT). Atrazine was the most effective herbicide reducing weed population and weed dry weight followed by Velpar. Weed growth in weedy plot caused 73.5% reduction in cane yield compared to weed free condition. Among herbicidal treatments, maximum cane yield of 82.4 t/ha was obtained in atrazine and no herbicide treatment was at par with this. Due to phytotoxicity reason Velpar K₄ 60 WP resulted in lower cane yield, though it effectively controlled the weeds.