Yield stability of water yam (Dioscorea alata L) landraces compared to improved varieties across multiple environments and their culinary qualities in the Republic of Benin

Background

In the Republic of Benin, the fresh yam market has two key periods: a time of high availability from August to February, followed by a scarcity from March to July. Fortunately, when Dioscorea rotundata fresh tubers become scarce and expensive, Dioscorea alata (commonly known as Agaabidjan/ Florido) pervades the market and provides a substitute, ensuring income for all value chain actors. Despite its importance, the gene pool of water yam is low and vulnerable in the growing areas.

Results

To assess the yield stability of water yam landraces grown in the traditional Beninese agriculture and identify elite genotypes, a genotype main effect and genotype-by-environment (GGE) interaction biplot analysis was conducted together with sensorial evaluation based on yam consumers preferences. Thirteen local and three improved varieties were assessed for fresh tuber yield and pounded yam quality across three locations over two consecutive seasons (2022 and 2023). Our findings showed that the accessions of three landraces Sakata Kpeguelehoun, Sakata Metchessa, Sakata Sossohoun) and two improved varieties (TDa0000194, TDa1510043) outperformed Florido in terms of yield, and three other landraces (Possoposso, Kpatampia, Lèssèlèssè) have similar yields.

Conclusion

Our results revealed that the most productive water yam accessions do not necessarily present a more stable yield across different environments. Sakata Metchessa stood out as a strong candidate for the national water yam-breeding program with good culinary features and high and stable yield in various environments. All landraces collected have their particularity, which highlights the importance of farmers in selection.