Effect of Different Herbicides on Rainfed Maize (Zea mays L.)

Abstract

A field experiment was conducted as part of an M.Sc. research programme to investigate the effect of different herbicides on rainfed maize (Zea mays L.) during the kharif (rainy) season of 2022 at the Department of Agriculture, Swami Vivekanand University, Sagar. The experiment comprised eight weed-management treatments: T₁, topramezone at 25 g ha⁻¹ applied at 20 days after sowing (DAS); T₂, atrazine at 1.25 kg ha⁻¹ applied at 20 DAS; T₃, 2,4-D sodium salt at 1.0 kg ha⁻¹ applied at 20 DAS; T₄, topramezone at 12.5 g ha⁻¹ + atrazine at 625 g ha⁻¹ applied as a tank mixture at 20 DAS; T₅, topramezone at 12.5 g ha⁻¹ + 2,4-D sodium salt at 500 g ha⁻¹ applied as a tank mixture at 20 DAS; T₆, the recommended weed-management practice comprising pre-emergence application of atrazine at 1.25 kg ha⁻¹ + IC + HW; T₇, weed-free treatment; and T₈, weedy check. The experiment was laid out in a randomised complete block design (RCBD) with three replications. The effects of the herbicidal treatments on the growth, yield attributes, and productivity of maize were evaluated. The principal growth parameters assessed included plant height (cm) and leaf area per plant (cm²), while the yield attributes and yield parameters included grain weight per cob (g), 100-seed weight (g), grain yield (kg ha⁻¹), and stover yield (t ha⁻¹). Among the herbicidal treatments, the application of topramezone at 12.5 g ha⁻¹ + atrazine at 625 g ha⁻¹ as a tank mixture resulted in significantly greater plant height at all recorded growth stages. Grain yield was also significantly influenced by the herbicide treatments. The tank mixture of topramezone at 12.5 g ha⁻¹ + atrazine at 625 g ha⁻¹ produced the highest grain yield (6,791 kg ha⁻¹), followed by the tank mixture of topramezone at 12.5 g ha⁻¹ + 2,4-D sodium salt at 500 g ha⁻¹ (6,609 kg ha⁻¹). Both tank-mixture treatments produced higher grain yields than the corresponding individual herbicide applications. Similarly, the highest stover yield (9.39 t ha⁻¹) was recorded with the tank mixture of topramezone at 12.5 g ha⁻¹ + atrazine at 625 g ha⁻¹. This treatment was statistically at par with topramezone at 12.5 g ha⁻¹ + 2,4-D sodium salt at 500 g ha⁻¹, which recorded a stover yield of 8.71 t ha⁻¹. Both tank-mixture treatments performed better than the individual herbicide applications with respect to stover production. In contrast, the lowest stover yield (7.00 t ha⁻¹) was recorded under the weedy-check treatment. Overall, the results indicated that the tank-mixture application of topramezone with atrazine, as well as topramezone with 2,4-D sodium salt, was more effective in improving the growth and yield performance of rainfed maize than the respective sole herbicide applications under the conditions of the present experiment.