Post-emergence herbicides enhance yield and profitability in Kharif maize (Zea mays L.)

Abstract

A field research on ‘Evaluation of postemergence herbicides in maize (Zea mays L.)’ was carried out at the research farm of ICAR-Indian Institute of Maize Research, Pusa Campus, IARI, New Delhi, India during Kharif season of 2017. It was found that the early post emergence tank-mix application of the pre-emergence (PE) and post-emergence (POE) herbicides and their sequential application increased crop growth parameters viz., plant population, plant height, dry matter accumulation (DMA), leaf area index (LAI) crop growth rate (CGR) and relative growth rate (RGR), yield attributes (cobs/ha, cob length, grains/row and grains/cob) in Kharif maize. However, no significant effects of different weed management practices were recorded on cob girth and grain rows/cob of the crop in our study. The application of the pre-emergence (PE) and post-emergence (POE) herbicides increased maize grain yield to the tune of 9.2 to 14.6 and 17.5 to 20 per cent over recommended practice (atrazine fb hand weeding), respectively. The increase in net returns over weedy check ranged from Rs. 15.12 ×103 (T5) to 56.19 ×103 (T10)/ha and gave 3-5 times more net returns in different herbicides applied treatments. The range of the added cost in weed management with post-emergence herbicide was Rs 5.02 ×103 to 6.55 ×103/ha over weedy check. Significantly the highest net returns (Rs. 56.19 ×103/ha), additional net returns (Rs. 53.09 ×103/ha) and benefit-cost (BC) ratio (1.59) in Kharif maize obtained by application of 75% recommended dose of atrazine as preemergence followed by topramezone (25.2 g/ha) at 25 DAS which was at par with the application of 75% atrazine as pre-emergence followed by at tembotrione (120 g/ha) 25 days after sowing (DAS) and with early postemergence tank-mix application of these combinations.