Weed dynamics and performance of lentil as affected by weed management practices under rainfed conditions

The field experiment was conducted at research farm of Tirhut College of Agriculture, Dholi of Dr. Rajendra Prasad Central Agricultural University, Pusa, Bihar during winter seasons of 2012–13 and 2013–14 to find out the suitable herbicides and their combinations for controlling weeds and improving yield of rainfed lentil (Lens culinaris). Study comprised post-emergence application of quizalofop-ethyl 50 g/ha or imazethapyr 37.5 g/ha, pre-plant application of chlorimuron-ethyl 4 g/ha, pre-emergence (PE) application of pendimethalin 300 g/ha, pendimethalin 154 g/ha + imazethapyr 10.5 g/ha (ready-mix), ready-mix pendimethalin 205 g/ha + imazethapyr 14 g/ha (ready-mix), pendimethalin 300 g/ha + hand weeding at 40 DAS, hand weeding twice at 20 and 40 DAS and weedy check. Hand weeding twice at 20 and 40 days after sowing caused the highest reduction (84.6%) in weed population (75.9 and 93.3% in monocot and dicot weeds, respectively) and registered the lowest nutrient depletion (13.6 kg/ha) by weeds. The highest seed yield (1.83 t/ha) obtained with hand weeding twice was 117.4% higher as compared to weedy check. The yield obtained under this treatment was at par with the combined application of pendimethalin 300 g/ha + hand weeding at 40 days after sowing (1.73 t/ha). However, the maximum B: C ratio (3.42) was obtained with application of pendimethalin 205 g/ha + imazethapyr 14 g/ha as PE followed by fb) their lower dose (pendimethalin 154 g/ha + imazethapyr 10.5 g/ha as PE). The chemical weed control was found economically better than hand weeding and weedy check.