Wheat productivity response to preceding rice residue-retention and integrated weed management

The sustainability of happy seeder (HS) sown wheat with preceding rice residue retention needs optimization of row spacing and integrated weed management. In this context, a study was conducted during Rabi seasons of 2020-21 and 2021- 22 at Punjab Agricultural University, Ludhiana, India. The objective was to evaluate and identify the best option to realize higher wheat productivity and better weed management in wheat sown with happy seeder (HS) using varying row spacings in combination with retained preceding rice residues and integrated weed management treatments. The tested treatments include: wheat sown with happy seeder at row spacings (HS row spacing) of 18.25, 20.0 and 22.5 cm and weed control treatments including: unsprayed check, pre-plant application (PPA) of pyroxasulfone 127.5 g/ha, pendimethalin 1125 g/ha PPA, pendimethalin + metribuzin 962.5 g/ha PPA and post-emergence application (PoE) of metribuzin + clodinafop 270 g/ ha. HS row spacing of 18.25 cm recorded P. minor density reduction of 16.7, 17.8% and 26.1, 27.1% and broad-leaved weeds density reduction of 22.1, 15.9% and 31.1, 27.8% at harvest, over HS row spacing of 20.0 and 22.5 cm, in 2020-21 and 2021-22, respectively. An increase in wheat grain yield of 24.9, 28.6% and 10.7, 16.3% was recorded with HS row spacing of 18.25 than HS row spacing of 20.0 and 22.5 cm during 2020-21 and 2021-22, respectively. Lower weed density (74.4%) and higher grain yield (82.9%) were recorded with metribuzin + clodinafop 270 g/ha compared to unsprayed check. Pendimethalin plus metribuzin 962.5 g/ha PPA by mixing with urea has provided greater control of diverse weed flora in wheat.