Efficiency of Early Post Emergence Herbicide and Integrated Weed Management Methods in Soybean (Glycine max) and their Residual effect on Succeeding Crops

摘要

Field experiments was conducted to evaluate the efficacy of imazethapyr on weed control in soybean and its residual effect on succeeding crops. The experiment was replicated thrice in randomized block design with ten treatments comprised of imazethapyr 50 (TJ, 75 (TJ, 100 (TJ and 200 (TJg/ha as early post-emergence (EPOE) was sprayed 15 days after sowing. All these treatments, xoere given with an earthing up on 45 DAS. oxyfluorfen 125 g/ha + hand weeding on 45 DAS (TJ, oxyfluorfen 125 g/ha + power iveeding on 45 DAS (TJ and Pendimethalin 750 g/ha + hand weeding on 45 DAS (T^), Pendimethalin 750 g/ha + power weeding on 45 DAS (TJ as pre-emergence (PE) were sprayed at 3 days after sowing (DAS), hand weedings at 25 and 45 days after sowing (TJ and unweeded check (control) (T_(10)). Imazethapyr at 200 g/ha has decreased the biomass of all weeds significantly which was followed by imazethapyr 100 g/ha. Imazethapyr at 200 g/ha caused phytotoxicity to soybean during intial stages resulting in reduced soybean yield and yield attributes. Early post emergence application of imazethapyr 100 g/ha reduced the density of broadleaved and grassy weeds as well as dry weight than sedges and recorded higher weed control efficiency and maximum in all growth attributes and yield attributes viz no of pods/plant, seeds/pod, 100 seed weight and gave higher grain yield, lowest nutrient removal by weeds and maximum nutrient uptake by the crop when compared with pre-emergence application of pendimethalin and oxyfluorfen. The residues of imazethapyr at different doses did not influence germination, groivth, yield of sunflower and pearl millet and was statistically at par with checks.