Integrating herbicidal and conventional approach for profitable weed management in groundnut (Arachis hypogaea)

A field experiment was conducted during the rainy seasons of 2009 and 2010 at Ludhiana, Punjab in the Indo-Gangetic alluvial plains, to work out an effective weed-management strategy in groundnut (Arachis hypogaea L.). Almost two-thirds of the weed infestation was dominated by sedges, followed by broad-leaf (26.3%) and grassy (9.3%) weeds. Season long weed competition reduced the mean seed yield of groundnut by 60.9%. Alone application of herbicides either through pendimethalin or imazethapyr provided effective weed control (43.5-53.3% weed-control efficiency) but the late flushes and escaped/regenerated weeds at later stages hampered the crop yield significantly. Integrated approach involving sequential application of pendimethalin 0.75 kg/ha pre-emergence (PE) and imazethapyr 0.05 kg/ha post-emergence (PoE) supplemented with 1 hand-weeding 45 days after sowing (DAS) provided 83.7% weed-control efficiency, 2.11 t/ha pod yield, (SIC)4.3 x 10(3)/ha net returns with benefit: cost ratio of 2.99 which was as good as implying 2 hand-weedings 3 and 6 weeks after sowing.