Assess the effect of different combinations of herbicides on weed population and economic feasibility of treatments in late sown wheat crop

The present investigation was conducted with objective to assess the effect of herbicides on weed density, physiology and economics. The experiment was laid out in randomized block design with three replications. The experiment was comprised ten treatments viz., T1 Pendimethalin @ 0.75kg/ha, T2 Metribuzin @200g/ha, T3 Clodinofop propargyl @ 400g/ha, T4 Sulfosulfuron methyl @ 25g/ha, T5 Metsulfuron @ 0.24g/ha, T6 Sulfosulfuron + metribuzin @1.14g/ha, T7 Sulfosulfuron + metsulfuron @0.096g/ha, T8 Isopruturon +2,4-D @ 6g/ha, T9 Weed check, T10 Weed free. The present investigation revealed that the major weed flora observed in the experiment were grassy weeds viz., Phalaris minor, Cynodon dactylon, Avena fatua and Broad leaf weeds viz., Chenopodium album, Anagallis arvensis, Convolvulus arvensis, Melilotus alba, Rumex spp. and sedges Cyperus rotundus. Among herbicides, post emergence application of Sulfosulfuron+ Metsulfuron@ 0.096 g ha-1 proved its superiority over other herbicides followed by post emergence application of Isopruturon +2,4-D@ 6 g ha-1for reducing number and dry weight of weeds at all the stages of crop growth. Application of Metribuzin @ 200 g ha-1registered highest dry matter accumulation over other herbicides followed by Pendimethalin @ 0.75kg/ha at all the growth stages of crop growth. Post emergence application of Sulfosulfuron+ Metsulfuron@ 0.096 g ha-1 registered highest weed control efficiency of 82.27% followed by post emergence application of Isopruturon +2,4-D@ 6 g ha-1 (79.11%). Weed infestation exhibited 31.16% loss in grain yield, which were minimized by post emergence application of Sulfosulfuron+ Metsulfuron @ 0.096 g ha-1 which recorded lowest value of weed index (2.809%) followed by post emergence application of post emergence application of Isopruturon +2,4-D@ 6 g ha-1 (5.36%).