Impact of crop establishment practices and herbicide sequencing on weed control, maize productivity, and soil microbial dynamics

Maize (Zea mays L.) is a globally important cereal cultivated across diverse agro-ecological regions due to its remarkable phenotypic plasticity and the highest genetic yield potential. Being a wet season crop in South Asia, weeds always remain a big challenge in harnessing its full potential. A two-year study was conducted by keeping three crop establishment methods viz., raised bed + residue (RB + R), zero tillage + residue (ZT + R) and conventional tillage + residue (CT + R) in main plots and five herbicidal treatments; pyroxasulfone as pre-emergence (PRE), pyroxasulfone (PRE) fb tembotrione as post-emergence (PST), atrazine (PRE) fb tembotrione (PST), unweeded check (UWC) and weed free check (WFC) in sub-plots and were executed in a split-plot design with three replications. Results indicated that comparatively lesser weed population and weed dry matter accumulation of all the weed flora present in the field were noted on RB + R compared to ZT + R and CT + R systems. Similarly, higher growth and yield of maize crop was obtained under RB + R compared to ZT + R and CT + R. Among different weed control treatments, pyroxasulfone fb tembotrione resulted in a substantial decline in the populations of grassy, broad-leaved weeds, and sedges by 66.2%, 58.2% and 41.2%, respectively (2-year mean) compared to the UWC. Significantly higher weed control efficiency (80.1%), weed control index (77.2%) and lowest weed index (8.56%) was found with pyroxasulfone fb tembotrione compared to other herbicide treatments. Pyroxasulfone fb tembotrione recorded grain yield enhancement of 44.8% over UWC. Therefore, it can be concluded that application of pyroxasulfone fb tembotrione in maize crop with raised bed coupled with residues, enhances maize productivity owing to significant decline in weed growth.