Reducing crop loss from Striga

Scientists based in Nigeria and Kenya started an initiative against two parasitic weeds that have spread across much of sub-Saharan Africa. These weeds cause losses of up to US$1.2 billion from damage every year to the maize and cowpea crops of millions of small farmers.

The project, coordinated by IITA, will introduce proven technologies for fighting Striga (witchweed), and Alectra, which attack crops such as maize and cowpea, reducing yields or destroying entire harvests.

Extension workers explains about the Striga problem. Photo from SP-IPM.
Extension workers explains about the Striga problem. Photo from SP-IPM.

Witchweed primarily affects smallholder farmers. The most widespread species is estimated to have infested up to 4 million ha of land under maize production in sub-Saharan Africa, with yield losses of up to 80%. IITA’s researchers estimate that this represents about $1.2 billion in losses for farmers and affects approximately 100 million people in the region.

The Striga project is supported by a grant from the Bill & Melinda Gates Foundation. It aims at helping 200,000 maize farmers and 50,000 cowpea farmers who work in areas with high rates of Striga infestation in Kenya and Nigeria. By the project’s end in 2014, organizers estimate that farmers will see up to 50% higher maize yields and 100% higher cowpea yields.

The 4-year project will focus on improving and expanding access to methods of Striga control, while supporting research to identify the most effective means of control under varying conditions. It will evaluate and implement four approaches: using Striga-resistant crop varieties; using a “push-pull” technology that involves intercropping with specific forage legumes that inhibit the germination of Striga; using herbicide-coated seeds; and deploying biocontrol of Striga. After a 2-year evaluation period, the project will scale up the most effective approaches.

Partners in the project are the International Maize and Wheat Improvement Center, African Agricultural Technology Foundation, International Centre of Insect Physiology and Ecology, and BASF Crop Protection. The poject will work with farmers, seed companies, community-based organizations, extension workers, policymakers, and researchers.

Scientists expect that the interventions will generate annually additional grain with an estimated value of $8.6 million at the project locations. This will result in increased incomes, better nutrition, and reduced poverty, and employment opportunities.