V. Pratap Singh, S.P. Singh, Abnish Kumar, Shalini, Neema Bisht, Kavita Satyawali and D.B. Singh
Abstract
A field experiment was conducted during 2012-13 and 2013-14 at G.B. Pant University of Agriculture & Technology, Pantnagar to study the bio-efficacy and phytotoxicity of halosulfuron methyl 75% WG for weed management in sugarcane and their residual effect on succeeding lentil crop. The treatments constituted of new herbicide formulation halosulfuron methyl (75% WG) at different doses i.e. 60, 67.5, 90.0 and 135.0 g/ha compared with atrazine as standard check 50%WP at 2000 g /ha, 2,4-D amine salt 58% SL at 3500 g/ha and two hoeing on 30 and 60 DAP with weedy check. The results revealed that halosulfuron methyl at 60, 67.5, 90.0 and 135.0 g/ha recorded significantly effective in lowering the dry matter of C. rotundus at 30 and 60 DAT (1.0-1.1g/m2) compared to atrazine 2000 g/ ha (3.6 g/ m2), 2,4 D amine salt at 3500 g/ha (1-1.6 g/m2) and hoeing 30&60 DAP (1.8-202 g/m2). Among herbicidal treatments highest cane weight (982 g) was obtained with atrazine applied as pre emergence at 2000 g/ha followed by post emergence application of halosulfuron methyl applied at 90 as well as 135 g/ ha. Halosulfuron methyl at 135 g/ha gave maximum cane yield (619 q/ha) which was at par with its other lower doses. The per cent increase in the sugarcane yield with the application of atrazine at 2000 g/ ha and post emergence application of halosulfuron methyl at 135 g/ ha was to an extent of 63.7 and 35.1%, respectively over weedy check. It was also observed that the herbicide tested in this study did not show any phytotoxic symptoms and residual effect on succeeding crop of lentil