WARDA IPM project 03: Integrated weed management in rice

Duration: Started 1990; a rolling programme

Purpose: To develop labour-saving methods to manage weed problems in rice production.

Background/description: Weeds are the problem most commonly cited by farmers in West Africa and limit the area that farmers cultivate.  Traditionally, farmers in the upland and rainfed lowland systems make use of fallows between rice crops to reduce the ingression and build-up of noxious weeds. Cropping intensification in the traditional rice production systems has resulted in reduced yields with increased weed growth accounting for about 50% of this reduction. In savanna areas, farmers have been able to intensify production through the adoption of animal traction that enables then to improve the level of seedbed preparation and weed control.  Herbicides are used by only a minority of farmers, but are more commonly used where farmers have access to credit, supplies and information. In the forest zone, where the majority of upland rice is grown, farmers do not have the possibility of utilizing animal traction to aid cultivation.  In these areas, the majority of the crops are grown with zero tillage and are reliant on the fallow periods between crops to control weeds. Weed management in rice production in Africa is an essential component of rice production practices yet, despite farmers’ efforts, weeds cause yield losses of 20–26% in Sub-Saharan Africa.

Agroecozone(s) and location(s): Humid Tropical forest, Derived savanna, rainfed uplands and lowlands, inland valleys in Nigeria and Senegal in West Africa.

Expected outputs: a) Decision support tools for weed management developed and disseminated; b) Improved fallow management practices established; c) Strategies to minimize losses due to weeds in rice developed; d) Rice cultivars highly competitive with weeds developed, evaluated and promoted.

Potential impact and beneficiaries: The primary beneficiaries will be the smallholder farmers and their families in West Africa whose returns to labour are seriously constrained by crop losses due to weeds. Labour saved due to improved weed management would be available for household activities or other enterprises such as raising vegetables or expanding the areas under cultivation. Reduced incidence of weeds would reduce the crop losses and improve labour productivity.

Partners: a) National Cereals Research Institute, Bida, Nigeria; b) NARES from Senegal, Côte d’Ivoire and Mauritania; c) International Rice Research Institute; d) Natural Resources Institute, University of Greenwich, Chatham, UK

Development investor(s): DFID and WARDA

WARDA contact person(s)/principal investigator(s): Website: www.warda.cgiar.org