Comparative effects of pre- and post-emergence herbicidal treatments on weed control, growth and yield of hybrid maize in Varanasi

Abstract

A field experiment was conducted during kharif 2023, Varanasi, India, to compare pre- and post-emergence herbicide combinations with different modes of action under an integrated weed management approach in hybrid maize. The experiment was laid out in a randomized block design with twelve treatments and three replications, comprising atrazine and pyroxasulfone-based pre-emergence applications followed by hand weeding or post-emergence herbicides (halosulfuron, tembotrione, topramezone, and mesotrione + atrazine). Weed parameters were recorded at 65 DAS. Among the treatments, pyroxasulfone 127 g/ha followed by one hand weeding at 25–30 DAS resulted in the highest weed control efficiency (90%) and significantly reduced weed density and dry weight compared to other treatments. This treatment also recorded superior growth attributes, including plant height (215 cm), dry matter accumulation (9.6 t/ha), leaf area index (3.18) and SPAD value (36.9). Consequently, higher grain yield (5.61 t/ha), stover yield (8.14 t/ha) and harvest index (40.82%) were obtained. Atrazine-based treatments were comparatively less effective, indicating possible limitations under continuous use. The results highlight that integrating residual herbicides such as pyroxasulfone with mechanical weeding ensures effective season-long weed control and improved productivity in maize under eastern Uttar Pradesh conditions.