Bioefficacy of herbicides in late-sown wheat (Triticum aestivum)

A field study was conducted during winter (rabi) seasons of 2000–2002 at Varanasi, to study the bioefficacy of oryzalin (0.05, 0.75, 1.00, 1.25 and 1.50 kg/ha), triasulfuron (0.015 and 0.020 kg/ha), pendimethalin (1.0 kg/ha) as pre-emergence and dicamba (0.025 kg/ha) as post-emergence in late-sown wheat (Triticum aestivum L. emend. Fiori & Paol.). Ail the herbicide treatments reduced the density and dry weight of narrow and broad-leaved weeds significantly compared with weedy check. Pre-emergence application of oryzalin at 1.25 kg/ha had minimum population and dry weight of weeds compared with other herbicides and their doses. Dicamba at 0.025 kg/ha was the most effective against broad-leaved weeds compared with other herbicides. Triasulfuron at 0.020 kg/ha proved more effective than its lower dose (0.015 kg/ha) and controlled both narrow and broad-leaved weeds. The maximum weed-control efficiency (76.65%) and grain yield (27.48 q/ha) were recorded with oryzalin at 1.25 kg/ha, followed by pendimethalin at 1.0 kg/ha and triasulfuron at 0.020 kg/ha.