Vegetos

Abstract

Field experiment was conducted during spring 2009 and 2010 in the Indo-Gangetic alluvial plains to evaluate the efficacy of different pre-emergence herbicides alone or in combination with hand weeding for effective weed management in sunflower. Season long competitional stress with weeds reduced the mean seed yield of sunflower by 43.5% in comparison to conventional practice of two hand weedings (3 and 6 weeks after sowing). Herbicide based weed management increased the sunflower yield by 52.6–71.6% in comparison to weedy check. Irrespective of herbicide dose, yield improvement to the tune of 5.5–12.5% was observed with weed management through either of the pre-emergence herbicide (oxydiargyl/alachlor) when compared with recommended herbicide application of pendimethalin @ 0.75 kg/ha. Integrated approach involving herbicides with one hand weeding 4 WAS resulted in better seed yields (3.1–4.4% superiority) but the profit margin gets reduced due to higher wages of human labour incurred. Alone application of alachlor 1.5 kg/ha resulted in highest monetary benefits with highest B: C ratio of 3.49 followed by oxydiargyl 0.1 kg/ha (3.35) which was as good as two hand weedings done 3 and 6 WAS. This study identifies pre-emergence application of alachlor 1.5 kg/ha or oxydiargyl 0.1 kg/ha as economically viable weed management strategy in sunflower considering the present situation of labour scarcity, quality of weed control, productivity and profitability concerns.