About

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.

AfricaYam Phase I began in October, 2014 and had three primary outcomes: 1. Active yam breeding programs in four countries in West Africa (Nigeria, Côte d’Ivoire, Ghana and Benin); 2. Improved efficiency of yam breeding programs through the use of faster and more precise tools and methods; 3. Breeding methods used in national and international yam breeding programs in West Africa for sustainable development of new yam varieties that combine high and stable yield with good tuber qualities. Phase I ended in August 2020.

AfricaYam phase II started in September 2020 and will focus, over the next 30 months, on further modernizing the yam breeding programs in West Africa. It will entail implementation of breeding strategies for the development and delivery of next generation of varieties that will be superior in agronomic performance and food quality and eventually become best choice for cultivation and consumption as compared to the current popular varieties in the production system. Phase-II will further strengthen human capacity in the partner programs through the training of a new generation of yam breeders and scientists. It will provide capacity on the use of appropriate experimental designs, obtaining higher quality data and maximize NARS breeders’ capability to develop improved varieties. It will help to identify traits preferred by a range of value-chain actors engaged in yam cultivation, marketing, processing and consumption and incorporate convenient list of “must-have” traits and “value-added” traits in product profiles to ensure that breeding is demand-driven and inclusive. In phase-II, we intend to explore all possible avenues including the use of new innovations in vegetative propagation such as Semi-Autotrophic Hydroponics (SAH) to shorten the yam breeding cycle and increase the availability of high-quality planting material for testing and variety release. Building on the genomic resources already developed, we will implement an accurate predictive platform to assess the genetic and phenotypic potential of breeding materials at different growth stages and testing cycle which will dramatically shorten the breeding cycle, increase the rate of progress and increase the number of genotypes that could be accurately evaluated. We will improve the accuracy of prediction models for breeding trials and breeders will have access to world class breeding tools to better understand traits of interest and use them in targeted crossing strategies. In parallel to predictive breeding, we will invest efforts to identify and exploit major QTLs controlling important agronomic traits with high heritability to improve breeding efficiency. While optimizing predictive breeding platforms for yam, emphasis will be given to mining the genomic and phenotypic data generated on mapping and GWAS population in phase I. We will then validate and deploy identified QTLs for forward breeding. Overall, we anticipate in this phase, well defined product profiles to breed for market needs, improved connection with national programs to scale testing capacity, refined number of traits to be evaluated in the breeding scheme and changes that will help make the breeding programs more efficient and higher throughput. Building on phase I successes, investment in phase II along with the CGIAR Crops to End Hunger Initiative will lead to a holistic optimization of yam improvement programs in West Africa that sustainably accelerate the rate of genetic gain at farmers field. To arrive at this, the phase II targets three flagship products or primary outcomes:

1. Enhanced capacity for more efficient and effective yam breeding programs in Ghana, Nigeria, Benin, Côte d’Ivoire and IITA.
2. New genomic resources and novel breeding methods and tools for enhanced yam breeding efficiency in West Africa
3. Next-generation of superior yam varieties for traditional and emerging products/markets.

Yam is the preferred staple food in West Africa and elastic demand is constrained by inadequate production and losses in storage.