Bio-efficacy of herbicide admixtures against composite weed flora in wheat under three methods of wheat seeding

The field experiment was conducted with an objective to assess the bio-efficacy of herbicide admixtures against composite weed flora in wheat (Triticum aestivum) under three methods of wheat seeding. It was conducted at Students’ Research Farm, Khalsa College, Amritsar during Rabi season of 2020-21 in split-plot design, replicated thrice, with three methods of sowing, viz. conventional tillage, super seeder and happy seeder in main plots and seven weed management treatments in sub-plots, viz. pinoxaden + clodinafop, fenoxaprop + metribuzin, metsulfuron-methyl + carfentrazone-ethyl + NIS, pendimethalin fb pinoxaden + metsulfuron-methyl, isoproturon + 2,4-D, weed free and weedy. Among the different methods of wheat seeding, greater weed density and biomass was observed in happy seeder sown wheat than the super seeder sown wheat, while the maximum weed density and biomass was observed in wheat sown with conventional tillage. Super seeder sown wheat recorded highest grain and straw yields as well as net return and B:C ratio. Among the various weed control treatments, pre-emergence application (PE) within 2 days after wheat sowing (DAS) of pendimethalin 900 g/ ha followed by (fb) post-emergence application (PoE) at 35 DAS of pinoxaden + metsulfuron-methyl 60 g/ha enhanced of growth, yield and benefit cost ratio of wheat which was at par with weed free, pinoxaden + clodinafop-propargyl 70 g/ha PoE and fenoxaprop + metribuzin 110 g/ha and significantly better than metsulfuron-methyl 4 g/ha + carfentrazone-ethyl 25 g/ha (PoE), isoproturon 750 g/ha + 2,4-D 500 g/ha PoE as compared to weedy check. Pendimethalin 900 g/ha PE fb pinoxaden + metsulfuron-methyl 60 g/ha PoE recorded the maximum wheat grain (5.42 t/ha), net returns (Rs. 87373/-) and B:C ratio (2.04).