Herbicide options for effective weed management in zero-till maize Mitra B.*,2, Bhattacharya P.M.2, Ghosh A.2, Patra K.2, Chowdhury A.K.2, Gathala M.K.1,2 2Uttar Banga Krishi Viswavidyalaya, Pundibari, Coochbehar, West Bengal, 736 165 1CIMMYT, Dhaka, 1212, Bangladesh *Email: bipmitra@yahoo.com
Abstract A field experiment was carried out during winter seasons of 2015–16 and 2016–17 at Uttar Banga Krishi Viswavidyalaya, Pundibari, Coochbehar, West Bengal with the objective of identifying weed management options with various pre-and post-emergence herbicides in zero-till maize in rice-maize cropping system. Three pre-emergence herbicides, viz. pendimethalin 1.0 kg/ha, atrazine 1.0 kg/ha and control in main plots and six post-emergence treatments, viz. atrazine (0.5 kg/ha), tembotrione (120 g/ha), halosulfuron (90 g/ha), tembotrione (120 g/ha) + atrazine (0.5 kg/ha), halosulfuron(90 g/ha) + atrazine (0.5 kg/ha) and control in sub-plots were evaluated in a split-plot design. Results revealed that both pendimethalin and atrazine reduced the grassy weed population to a significant extent and among the pre-emergence herbicides, atrazine resulted in maximum reduction in grass weed population (69% reduction over the weedy check) at 20 days after seeding (DAS). Among the post-emergence herbicides, mixture of tembotrione + atrazine was more effective in controlling all classes of weed flora at 40 and 60 DAS. Tembotrione alone also showed a good control of grasses and broad-leaved weeds. Atrazine as pre-emergence followed by (fb) tembotrione + atrazine as post-emergence had significantly lower weed biomass (2.9 and 7.5 g/m2 at 40 and 60 DAS, respectively) and this combination reduced the weed dry matter to the tune of 98.7 and 97.9% at 40 and 60 DAS, respectively which ultimately resulted in significantly higher grain yields (11.57 t/ha) with maximum net returns (‘ 74210/ha) and B: C ratio (2.73). A strong negative correlation between weed biomass at 60 DAS and maize grain yield clearly suggested that weed biomass accounted for 55% variation in grain yield of zero-till maize. Top Keywords Atrazine, Economics, Halosulfuron, Maize, Pendimethalin, Tembotrione, Weeds, Zero tillage. Top |