About Yam Crop
More than 54 million tons of yams are produced in Sub-Saharan Africa annually on 4.6 M Ha. Over 95% of this production lies in a five-country “yam belt” that includes Nigeria, Benin, Togo, Ghana, and Côte d’Ivoire. Although yam production in Africa is 40% that of cassava, the value of yam production exceeds all other African staple crops and is equivalent to the summed value for the top three cereal crops (maize + rice + sorghum). Yam is the preferred staple food in West Africa and elastic demand is constrained by inadequate production and losses in storage.
The most important biotic constraints are nematodes, viruses, and anthracnose. Yam cultivation has high environmental impact because it is usually planted into recently cleared land and requires staking with branches/small trees, especially in the forest areas.
Yam productivity is negatively impacted by declining soil fertility and soil-borne nematodes associated with intensive cropping systems. Genetic improvement can contribute significantly to addressing these challenges and seizing opportunities for expanding the markets for the commodity.
Important traits for breeding include yield, tuber quality, resistance/tolerance to diseases (yam mosaic virus and anthracnose) and nematodes. However yam breeding is challenging, there is limited current capacity for it in West Africa, and relatively little has been done to date.
What we do
The AfricaYam project focuses on genetic improvement of two major cultivated yam species which are white yam (Dioscorea rotundata), which is native to West Africa, and water yam (D. alata) which originated from the Asia/Pacific region. The project is led by IITA and involves a network of research organizations in the four main producer countries of the yam belt: the National Root Crops Research Institute (NRCRI) and the Ebonyi State University (EBSU) in Nigeria; two research institutes under the Council for Scientific and Industrial Research (CSIR) in Ghana (the Crops Research Institute and the Savanna Agricultural Research Institute; le Centre National de Recherche Agronomique (CNRA), Côte d’Ivoire; and l’Université d’Abomey-Calavi (UAC), Dassa Center, Benin.
Some research organizations outside the sub-region have also been identified to play key roles in the project. These are the Centre de Coopération Internationale en Recherche Agronomique pour le Développement (CIRAD), France; the Iwate Biotechnology Research Center (IBRC), Japan; the James Hutton Institute (JHI), UK; Japan International Research Center for Agricultural Sciences (JIRCAS), Japan; and the Boyce Thompson Institute for Plant Research (BTI), Cornell University, USA.
The project partners will work towards a vision to increase yam productivity whilst reducing production costs and environmental impact by developing and deploying varieties with higher yield, greater resistance to pests and diseases and improved quality.
The key objectives for working towards this vision are:
- Breeding for high yield, good quality, nematode and resistance to diseases (anthracnose and yam mosaic virus)
- Establishing a breeders’ community of practice for participating countries with a focus on upgrading skills in phenotyping, breeding, program management, and trial management
- Regional testing of promising breeding selections currently available.
- Phenotyping for bi-parental population mapping and genome-wide association studies for key agronomic and quality traits
- Additional re-sequencing, sequence analysis for generation of genomic tools for genotyping populations, genome-wide association studies, and testing feasibility of genomic selection
- Constructing and using a database for curation and integration of yam research data
- Training and capacity building