Isoproturon, pendimethalin, residue retention, straw burning, sulfosulfuron, tillage

The studies were conducted to determine the effect of straw retention and burning on Phalaris minor control. Reduced herbicide (isoproturon and pendimethalin) efficacy and increased P. minor infestation were observed with rice straw burning. A survey conducted in rice-wheat system revealed that majority of the farmers (65%) were burning rice straw in north-western Indian plains. For sustainability of rice-wheat system, instead of burning, residue should be either retained on surface or incorporated. The surface retention of rice residue of 5.0 and 7.5 t/ha reduced the weed dry weight in wheat by 23.4-30.3 and 35.5-44.1%, respectively. However, the yield and weed control were lower in various residue retention treatments without herbicides as compared to the herbicide application (sulfosulfuron 25 g/ha+metsulfuron 3 g/ha). Considering advantage of residue retention, efficient weed management options need to be evolved under such residue management practices