Suitable weed management practices for dual purpose Sorghum K12 under Irrigated condition

Abstract

A field experiment was investigated at Agricultural College and Research Institute, Killikulam for evaluating suitable weed management practices for dual purpose sorghum variety K 12 (Sorghum bicolor L.) under irrigated condition during rabi season, 2019-20. The experimental design used for the investigation was Randomized Block Design having three replications and twelve treatments. The weed management practices comprised of pre emergence herbicides namely atrazine @ 0.5 kg ha-1 and pendimethalin @ 0.5 kg ha-1, post emergence herbicides viz., 2,4-D @ 0.5 kg ha-1 and metsulfuron methyl @ 6 g ha-1 with combination of hand weeding and mechanical weeding. Observations on weeds like weed flora, weed dry weight, weed density, weed control efficiency and on growth parameters like plant height, leaf length and breadth and yield parameters like grain and stover yield were documented. The field was infested with all three genera of weeds viz. grasses, broadleaved weeds and sedges. The results obtained from the experiment revealed that the weed density and weed dry weight was higher on the unweeded plot, which produced the lowest grain and stover yield of 1672 kg ha-1 and 5380 kg ha-1, respectively. Application of atrazine @ 0.5 kg ha-1 as pre emergence + one hand weeding at 40 DAS showed a better control over the weeds with a weed control efficiency of 97.0 per cent, which ultimately resulted in higher yield producing 3998 kg ha-1 of grains and 11534 kg ha-1 of stover yield. However, this was on par with weed free check which produced the maximum yield compared to all the other treatments. The weeds accounts around 51.4% and 39.4% of grain and stover yield reduction, respectively.