Direct and residual effect of varying levels of herbicides for controlling the weeds in potato-blackgram crop sequence

Pre-emergence herbicides viz. oxyfluorfen (0.10, 0.15 and 0.20 kg/ha), metribuzin (0.50, 0 75 and 1.00 kg/ha) and methabenzthiazuron (1.00, 1.25 and 1.50 kg/ha) were evaluated alongwith norma] practice of weed control (weeding-(-earthing up) and weedy check (control) treatments in potatoes at Central Potato Research Station Modipuram, Meerut (U.P.). All the herbicides at the varying levels significantly reduced the weed growth and increased the tuber yield as compared with control. The lowest levels of different herbicides tested were found sufficient for weed control in potato crop. However, the maximum weed control efficiency in potato and the residual effect of different herbicides for weed control on succeeding bJackgram were in favour of higher levels of herbicides. Metribuzin was the most effective herbicide for controlling the weeds through direct as well as residual effect followed by methabenzthiazuron in potato-blackgram crop sequence.