Screening of Beans (Phaseolus vulgaris L.) Genotypes for Drought Tolerance

Abstract

Drought is a critical factor that limits crop yield and contributes to global food insecurity. In regions where beans are cultivated, 60% of the crop is vulnerable to drought, resulting in an 80% reduction in yield. This presents a growing threat to farming communities in Bhutan, where limited research on crop drought tolerance has been conducted. To address this issue, a study was undertaken to evaluate the drought tolerance of six bean genotypes: Orey serbu, Orey regtang, Orey brokchilu, Yadhipa orey, Kerongree orey, and Brokopali. The study employed a Completely Randomized Design (CRD) consisting of six treatments each with three replications. The genotypes were subjected to drought stress after 50% flowering until the onset of pod formation, with drought conditions maintained for 10 days during pod formation, followed by restored irrigation until harvest. Key parameters such as leaf area, root weight, shoot weight, as well as yield metrics including the number of pods and seed weight, were assessed at harvest. The findings indicated significant differences (p<.05) in all parameters measured under stressed versus non-stressed conditions. Water stress was found to adversely affect the growth and development of all bean genotypes. With performance as regards to Drought Susceptibility Index (DSI) which is a measure of yield stability (DSI = (1- Yd / Yw) / D. Brokpali, Yadhipa orey, and Orey serbu demonstrated the lowest values for the drought susceptibility index (DSI), suggesting a greater level of tolerance to drought for these specific genotypes.