A recent impact study based on DNA analysis of plant samples and a survey of farmers shows that WorldVeg-developed amaranth varieties have become widely adopted in Tanzania. It found that 67% of amaranth producers grow these varieties and that they produced on average 6.1 tonnes per hectare more than local varieties. The results, published in the journal Food Security (Wanyama et al. 2023), provide important evidence for the significant positive impact of investing in the breeding of traditional vegetables.

 Amaranthus is a genus of some 75 species, many of which were very important sources of food grains in the pre-Columbian Americas. It is known to gardeners in northern climes as a colorful ornamental, or to farmers as a weed, but in Africa and Asia it is a popular leafy vegetable rich in micronutrients and in some countries, where seeds are also consumed as a grain. When WorldVeg established its first station in Africa in 1992, in Arusha, Tanzania, its scientists identified amaranth as a priority vegetable for research, alongside African eggplant and other traditional African vegetables, and that evolved into a large scale breeding programme in the 2000s (Dinssa et al. 2016).

Centuries of use and seed exchange by farmers across Africa have created a wide diversity of locally adapted varieties. WorldVeg researchers and partners collected seeds, stored in the WorldVeg genebank in Arusha, and selected from the available genetic diversity, and evaluated the most promising lines for yield and farmer preference. Later, crosses were made that combined favorable traits in new vegetable and grain type varieties, as well as dual-purpose (vegetable and grain) varieties. The best performing varieties were distributed to tens of thousands of farmers in East Africa as small seed samples through various projects, with 26,541 amaranth seed samples provided to farm households in Tanzania alone from 2013-2017 (Stoilova et al. 2019).

An earlier study found that WorldVeg varieties were planted on 47% of the area under amaranth by 174,000 households across Tanzania, based on estimations from 48 interviewed experts (Ochieng et al. 2019). This was very promising, but a more rigorous analysis was needed. So, leaf samples were collected across Tanzania, brought to Taiwan for DNA fingerprinting, and compared to the WorldVeg amaranth germplasm DNA library. Researchers expected to find an adoption rate below the 47% estimated, as expert opinion is likely to create a positive bias, but were surprised to find that WorldVeg-related varieties in fact occupied 66% of the amaranth area in Tanzania, and grown by 67% of producers. Also, farm survey data collected alongside the plant samples showed that the mean yield of WorldVeg varieties was 6.1 tonnes per hectare higher than that of other varieties.

Traditional vegetables have received low priority in agricultural research to date, which is still heavily biased toward calorie-laden staple food crops. However, WorldVeg research shows that investments in the improvement of traditional vegetables yield relatively quick and large-scale impacts.

This study was funded by the Federal Ministry of Economic Cooperation and Development (Germany) and UK aid.

 Pepijn Schreinemachers and Fekadu Dinassa

References

Dinssa, F.F., P. Hanson, T. Dubois, A. Tenkouano, T. Stoilova, J. d’A. Hughes, and J.D.H. Keatinge. 2016. AVRDC – The World Vegetable Center’s women oriented improvement and development strategy for traditional African vegetables in sub-Saharan Africa. European Journal of Horticultural Science, 81(2):91-105. http://dx.doi.org/10.17660/eJHS.2016/81.2.3

Ochieng, J., P. Schreinemachers, M. Ogada, F.F. Dinssa, W. Barnos, and H. Mndiga. 2019. Adoption of improved amaranth varieties and good agricultural practices in East Africa. Land Use Policy, 83:187-194. https://doi.org/https://doi.org/10.1016/j.landusepol.2019.02.002

Stoilova, T., M. Van Zonneveld, R. Roothaert, and P. Schreinemachers. 2019. Connecting genebanks to farmers in East Africa through the distribution of vegetable seed kits. Plant Genetic Resources: Characterization and Utilization, 17(3): 306-309. https://doi.org/10.1017/S1479262119000017

Wanyama, R., P. Schreinemachers, J. Ochieng, O. Bwambo, R. Alphonce, F.F. Dinssa, Y‑P. Lin and R. Schafleitner. 2023. Adoption and impact of improved amaranth cultivars in Tanzania using DNA fingerprinting. Food Security, 15:1185-1196. https://doi.org/10.1007/s12571-023-01378-0