Identification of drought tolerant sweetpotato (Ipomoea batatas L.) genotypes using yield based indices

The challenges of climate change and population growth pose a threat to global food security, underscoring the need for drought tolerant crops. Sweetpotato, a nutrient dense crop with potential for food security shows variability in drought response across genotypes. This study aimed to identify drought‑tolerant sweetpotato genotypes by screening 14 genotypes using yield‑based drought tolerance indices. The sweetpotato genotypes were evaluated at the National Root Crops Research Institute, Kuru, Nigeria, under irrigated and drought conditions using ten yield based drought tolerance indices. The experiment was conducted in a randomized complete block design with three replicates. The genotypes Amaroke, TIS 0087/87, and Umuspo 3 ranked highest for drought tolerance due to high yield stability under stress, while Tu-purple and Kwara were most susceptible. Yield under irrigated and drought stressed conditions was strongly correlated with geometric mean productivity ( r = 0.99), mean productivity ( r = 0.99), harmonic mean ( r = 0.98), tolerance ( r = 0.95), stress tolerance index ( r = 0.95), yield index ( r = 0.94), and stress susceptible index ( r = 0.74), identifying these indices as reliable tools for genotype screening of sweetpotato for drought tolerance. These results provide a basis for selecting drought tolerant sweetpotato genotypes for multi-locational trials and supporting breeding programs targeting drought prone environments.