Effect of rice straw burning on the efficacy of herbicides in wheat (Triticum aestivum)

The field trials on wheat (Triticum aestivum emend. Fiori & Paol.) were con ducted during 1992-94 at Uchani (Karnal) to find out the effect of rice str aw burning and weed control treatments on Phalaris minor and wheat yield. B urning of the straw (6 or 12 tonnes/ha) increased the population and dry we ight of weed, and decreased the wheat yield over straw removal. Isoproturon (1.00 and 1.25 kg/ha) and pendimethalin (1.50 kg/ha) being on par brought about significant control of weeds reading to increased wheat yield over we edy check. Weed infestation 90 DAS was greater in burnt plots than in unbur nt plots, and the herbicides were more effective under unburnt conditions i ndicating their reduced efficiency under straw burnt conditions.