Bio-efficacy of herbicide mixtures against complex weed flora in wheat (Triticum aestivum)

A field experiment was conducted at Baraut in Uttar Pradesh during 2001 -02 and 2002-03 to study the effect of different herbicides as sole and their tank mixtures on wheat (Triticum aestivum L. emend. Fiori & Paol.). The highest grain yield of 4.49 t/ha was recorded with fenoxaprop-p-ethyl + carfentrazone (100 + 10 glha) applied 30 days after sowing, which was at par with weed-free treatment. The lowest dry weight of weeds (22.0'g/m2) and highest weed-control efficiency (84.7%) were observed with fenoxaprop-p-ethyl + carfentrazone due to control of grassy and broad-leaf weeds. Although the tank mixture of isoproturon + carfentrazone showed greater control of broad-leaf weeds, it gave significantly lower control of grassy weed (Phalaris -minor) compared with fenoxaprop-p-ethyl + carfentrazone. Metsulfuron alone at 4 and 8 g/ha was found superior to 2,4-D and carfentrazone 10 g/ha for dry weight of weeds and weed-control efficiency. There was reduction of 25.7% in seed yield under weedy check conditions. None of herbicide alone or in mixture showed residual effect on suc- ceeding crops of fodder maize and mungbean.