Weed management in zero till-maize

Rainy season maize contributes 85% of the total maize area in India. Among major Rabi maize growing States, earlier Andhra Pradesh contributed maximum with 45.5% share. The present review reveals that Echinochloa colona L. is the most dominant weed species with importance value index (IVI) of 37.64 followed by Panicum repens L. (32.29), Trianthema portulacastrum L. (16.33) and Digera arvensis L Forsk (13.37). Wider spacing and initial slow growth of maize during the first 3–4 weeks provides enough opportunity for weeds to invade and offer severe competition, resulting in 30–93% yield losses. Among weed management practices, hand weeding twice at 15–21 DAS and 30–42 DAS, and integrated weed management like pre-emergence application of atrazine 1.5 kg/ha, pendimethalin 1.50 kg/ha, atrazine + alachlor 0.75 + 1.25 kg/ha, or alachlor 1.5 kg/ha followed by hand weeding at 30 DAS was found effective. Among sequential applications, atrazine as pre-emergence 1.25 kg/ha, or pendimethalin as preemergence 1.5 kg/ha followed by paraquat 0.6 kg/ha at 3 weeks after sowing or atrazine 1.0 kg/ha as preemergence followed by topramazone 0.030 kg/ha at 30 DAS were found economical with higher gross returns, net returns and B: C.