Weed management in rice based zero tilled sown wheat.

A field experiment was conducted at Research Farm of Directorate of Plant Protection, Quarantine and Storage, Faridabad, Haryana, India to study the weeds spectrum and weed control efficacy of different herbicides and their combinations in zero tilled sown wheat during 2003-04 and 2004-05. The experiment was laid out in a randomized complete block (RCB) design with three replications. During both the years the lowest weed population (2 to 5 weeds m -2 ), weeds dry matter (5.25 to 7.51 g m -2 ) and highest yield of 3850 and 3375 kg ha 1 during 2003-04 and 2004-05, respectively of wheat was recorded from the treatments of paraquat 0.5 kg a.i.ha -1 two days before sowing followed by isoproturon 1.0 kg a.i.ha -1 and 2,4-D 0.5 kg ha -1 at 30 days after sowing (DAS). However, it was found at par with hand weeding at 30 and 40 DAS. The highest weed control efficiency (WCE) 89.2 and 86.7 per cent was recorded from application of paraquat + isoproturon + 2,4-D and two hand weeding, respectively in 2003-04. The corresponding WCE was 92.2 and 90.6 per cent during 2004-05. Net profit was also highest in the plots treated with paraquat + isoproturon + 2.4-D followed by the plots treated with paraquat 0.5 kg a.i. ha -1 two days before sowing. Weedy check realized the lowest net profit of Rs. 10518 (US$257) and Rs.4484 (US$109 ha 1 ) in 2003-04 and 2004-05, respectively.