Identification of drought tolerant potato varieties for semi-arid conditions of Kenya

Potato (Solanum tuberosum L.) is a starch dense food crop that can alleviate chronic hunger in Sub-Saharan Africa. However, diminishing yield in traditional potato production regions in Kenya due to depletion in soil nutrient stock, high prevalence of soil-borne diseases, increased temperatures, and droughts have been observed. This study evaluated the adaptation of different potato varieties for potential production in dry areas of Kenya. A total of 16 potato varieties were screened under two-field experiments for two seasons based on randomized complete block design with non-irrigated (NOI) and irrigated (IRG) or control constituting the treatments. The treatments resulted in significant (P ≤ 0.05) differences between varieties for both growth and yield parameters. Higher number of vines/stems were recorded in two varieties ‘Sherekea’ (12) and ‘Tigoni’ (10); three varieties (‘Dutch robyjin’, ‘Shangi’ and ‘Sherekea’) showed higher chlorophyll contents; two varieties, ‘Sherekea’ (29) and ‘Dutch robyjinv’ (30) had higher number of tubers while ‘Tigoni’ and ‘Kenya Mpya’ varieties yielded higher cumulative fresh tuber weight of 38.7 and 40.7 tons/ha respectively. For drought stress tolerance indices, geometric mean productivity and mean productivity index exhibited stable associations with both yields under NOI and IRG conditions at both experimental sites. Overall, variety ‘Konjo’ and ‘Chulu’ were respectively better adapted for production at Kangundo and Mitaboni regions while variety ‘Nyota’ exhibited higher tolerance to drought stress at both sites and thus could be considered for production under arid and semi-arid conditions.