copiesBIO-EFFICACY OF SAND MIX APPLICATION OF PREEMERGENCE HERBICIDES ALONE AND IN SEQUENCE WITH IMAZETHAPYR ON WEED CONTROL IN RELAY CROP OF BLACKGRAM

A field experiment was conducted during winter seasons of 2007-08 and 2008-09 to study the bio-efficacy of sand mix application of pre emergence herbicides, pendimethalin 1000 g ha-1, pretilachlor 500 g ha-1, oxyfluorfen 120 g ha-1, imazethapyr 63 g ha-1 alone and in sequence with post emergence application of imazethapyr 50 g ha-1 on weed control in black gram grown as relay crop. Results indicated that sequential treatments were found to be superior to individual applications. Among the sequential treatments, pre emergence sand mix application of pendimethalin 1000 g ha-1 followed by imazethapyr 50 g ha-1 at 20 days after sowing (DAS ) significantly reduced weed growthand recorded the highest seed yield (1113 kg ha-1), net monetary returns (Rs.2255 ha-1) and B:C ratio (1.33) and was at par with other sequential treatment, oxyfluorfen 120 g ha-1 followed by imazethapyr 50 g ha-1 and also with hand weeding at 15 and 30 DAS. Uncontrolled weed growth caused 61 percent reduction in seed yield of blackgram.