Effect of Integrated Weed Management on Yield and Yield Component of Bread Wheat in Guji Zone, Southern Oromia

Abstract

Bread wheat (Triticum aestivum L.) is one of the most important food crops in the world, providing a staple food for over 35% of the global population; in Ethiopia, however, production in highland regions like the Guji zone is severely constrained by heavy weed infestation, causing significant yield gaps. While Integrated Weed Management (IWM) is a promising solution, locally validated and economically feasible strategies for this specific agroecology are lacking. Therefore, this study was conducted to evaluate the agronomic performance and economic viability of different weed management practices in bread wheat. A field experiment was conducted over the 2021 and 2022 main growing seasons at two locations in the Guji zone using a Randomized Complete Block Design. Ten treatments, including herbicides (Salon 5 OD, Zura 2, 4-D), manual weeding, and their integrated combinations, were evaluated. Results revealed that all weed management treatments significantly outperformed the weedy check. The integrated treatment of Salon 5 OD followed by one hand weeding was most effective, reducing final weed density to 3.37 plants m⁻² compared to 12.34 plants m⁻² in the weedy check. This superior weed control translated directly into yield, with the same integrated treatment producing a grain yield of 3,623.7 kg ha⁻¹, a 145% increase over the weedy check (1,480.7 kg ha⁻¹). Economically, this strategy also yielded the highest net benefit (85,446.55 ETB ha⁻¹) and the highest marginal rate of return (3,656.90%). It is concluded that an integrated approach is essential for managing the mixed weed flora in the Guji zone. Based on its high efficacy, excellent grain yield, and superior profitability, the application of Salon 5 OD supplemented with one timely hand weeding is recommended as the most economically viable and sustainable weed management strategy for wheat farmers in the study area and similar agroecologies.