Response of Crop Establishment Methods and Weed Management Practices on Weed Flora, Crop Growth and Yield of Wheat in Maize-Wheat-Greengram Cropping System

Abstract

Sustainable agriculture mostly relies on conservation tillage, crop residue retention and crop diversification. Weeds are major production hurdles in adoption of conservation agriculture (CA), therefore, weed management is important for sustainable crop yield. Designing efficient integrated weed management (IWM) practices under zero-tillage with crop residue (ZT+R) is helpful in getting optimum yield. A field experiment was carried out at research farm of ICAR-Directorate of Weed Research, Jabalpur (M.P.), India with eight treatment combinations, two crop establishment methods (conventional tillage and conservation tillage) in main plots and four weed management practices (weedy check, recommended herbicide, IWM, and herbicide rotation) in sub-plots were evaluated using a split plot design with three replications. The results indicated  that the wheat sown under ZT+R led to significantly less weed density (105.9 no. m-2 in 2020-21 and 122.8 no. m-2 in 2022-23) and biomass (149.7 and 174.2 g m-2, respectively) hence, registered the highest weed control efficiency (WCE, 72.3% and 71.2%, respectively). Higher WCE helped in producing better wheat growth indices like plant height (106.3 and 101.1 cm, respectively), biomass (12.0 and 9.0 g plant-1, respectively) and no. of tillers (488.0 and 391.3 no. m-2, respectively) ultimately grain yield (4164 and 3814 kg ha-1, respectively) and straw yield (7265 and 6834 kg ha-1, respectively) compared with conventional tillage during both the years. Among the weed management practices, ready-mix application of clodinafop + metsulfuron at 60+4 g ha-1 (30-35 days after sowing, DAS) followed by (fb) hand weeding at 45 DAS increased growth indices like plant height (110.2 and 105.0 cm, respectively), plant biomass (14.9 and 12.1 g plant-1, respectively) and no. of tillers (547.2 and 436.7 no. m-2, respectively) ultimately grain yield (4708 and 4299 kg ha-1, respectively) and straw yield (7836 and 7610 kg ha-1, respectively), and WCE (97.4% and 96.8% respectively) with significantly less weed density (25.7 and 35.0 no. m-2, respectively) and biomass (13.6 and 19.9 g m-2, respectively) at 90 days after sowing. IWM also completely reduces the weed density and biomass over the other weed management practices during both the years. Therefore, wheat sown under ZT+R coupled with IWM was superior in terms of weed control, crop growth and yields.