Weed management in rainfed lowland rice ecology in Nigeria – challenges and opportunities

Abstract

Developing an effective weed management strategy is crucial to sustainable rice production in Nigeria. Rainfed lowland ecology contributes significantly to the volume of rice cultivated in the country in terms of yield and land acreage. Nevertheless, increased weed infestation remains one of its major production constraints. This review highlights the strength and weaknesses of weed management practices in rainfed lowland ecology, potential research gaps, and discusses the potential of a sustainable weed management strategy for lowland rice. In this review, a rainfed lowland situation is described (where water is limited) to engage flooding as a potential weed control option, due to the undulating land terrains. Effective weed management begins with creating a weed-free environment at the critical crop growth stages, such that broadcasted or transplanted rice seedlings can efficiently utilize water, nutrients, and light. Sustainable weed management practices in Nigerian lowland ecology would therefore imply that farmers begin to incorporate crop rotation to suppress problem weed pressure in continuous rice cropping systems, adopt conventional or minimum tillage to enhance herbicide efficacy and early establishment of rice, adopt weed competitive and high yielding cultivars, and practice appropriate spacing, seeding rate, and seeding methods that can support easy adoption of mechanical weeders and optimum plant population to suppress weed pressure at a later growth stage. This is feasible where farmers are supported with infrastructural facilities, farm machinery, and necessary inputs. Future research should engage lowland rice farmers in specific agroecological zones.