Bioefficacy and phytotoxicity of different new herbicide molecules on weed growth, crop growth and yield parameters of maize

摘要

Different new herbicide molecules were evaluated at the main research station, University of Agricultural Sciences, Hebbal, Bengaluru on bioefficacy, weed suppression, phytotoxicity, crop growth andyield in maize during Kharif 2017. Five treatments including application of four new herbicide molecules (tembotrione, topramezone, dimethanamid and halosulfuron methyl) at 20 days after sowing (DAS), 2,4-D sodium salt at 20 DAS, atrazine at 3 DAS, passing cycle weeder followed by hand weeding at 20 and 35DAS and unweeded control were replicated thrice in RCBD. The weed density (48.7 and 102.7 m~2, respectively) and weed dry weight (15.5 and 74.3 g m~(-2), respectively) at 45 and at harvest were significantly lower with application of topramezone 33.6 %SC + dimethanamid-P 23.4 % SC 570 g a.i. ha1 at 20 DAS among herbicide treatments and was on par with passing cycle weederfollowed by hand weeding at 20 and 35 DAS (26.7 and 91.0 m~2, respectively and 2.63 and 68.9 g m~2, respectively). The crop growth parameters, yield attributes and kernel yield (6556 kg ha~(-1)) were recorded highest in passing cycle weeder followed by hand weeding at 20 and 35 DAS followed by topramezone 33.6 % SC + dimethanamid-P 23.4 % SC 570 g a.i. ha~(-1) at 20 DAS (6397 kg ha~(-1)). However, the least maize kernel yield was recorded under weedy plot (2929 kg ha1). New herbicide molecules used in present investigations did not cause any phytotoxic symptoms on maize crop.