Atrazine

Economics

Halosulfuron

Maize

Pendimethalin

Tembotrione

Weeds

Zero tillage

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.