Evaluation of post-emergence herbicides in kharif maize (Zea mays L.).

Abstract

Topramezone, halosulfuron and tembotrione are the selective, post-emergence herbicides that have been recently introduced for use in maize. These provide an easy option for herbicidal-based weed management in maize especially late in the season which is the critical period of crop-weed competition. The experiment was conducted to understand the effect of post-emergence herbicides on weed dynamics and crop growth of maize as well as the effect of post-emergence herbicide application on yield and economics of maize. The treatments were T1:Weedy check, T2: Weed free check, T3: Atrazine 1000 g/ha (PE) fb hand weeding at 25 DAS, T4: Topramezone 30 g/ha at 25 DAS, T5: Halosulfuron 75 g/ha at 25 DAS , T6: Tembotrione150 g/ha at 25 DAS, T7: Topramezone 25.2 g/ha + atrazine 750 g/ha at 15 DAS ,T8: Halosulfuron 67.5 g/ha + atrazine 750 g/ha at 15DAS, T9: Tembotrione 120 g/ha + atrazine 750 g/ha at 15 DAS, T10: Atrazine 750 g/ha (PE) fb topramezone 25.2 g/ha at 25 DAS, T11: Atrazine 750 g/ha (PE) fb halosulfuron 67.5 g/ha at 25 DAS, T12: Atrazine 750 g/ha (PE) fb tembotrione 120 g/ha at 25 DAS. It was concluded that the application of post emergence herbicide viz., tembotrione (120 g/ha)/topramezone (25.2 g/ha) as tank-mix as early post-emergence at 15 DAS with 75% recommended dose of the atrazine (750 g/ha) or as sequential application at 25 DAS after 75% atrazine as PE may be adopted for better weed control, higher yield and net return in kharif maize.