Assessment of drought tolerance indices in faba bean genotypes under different irrigation regimes

Drought stress has devastating impacts on faba bean production, particularly with the current abrupt climate changes in arid environments. Hence, it is essential to identify drought-tolerant genotypes. The present study aimed at assessing six faba bean genotypes under three irrigation levels during two winter successive growing seasons (2018/2019 and 2019/2020). The applied irrigation levels were well-watered (every 4 days (D1), moderate drought every 8 days (D2), and severe drought 12 days (D3)) regimes. The analysis of variance exhibited highly significant differences among genotypes, irrigation treatments, and their interactions for all studied traits, except the number of pods plant(-1) in the first season. Yield traits of all assessed genotypes decreased significantly with increasing drought stress. Otherwise, proline content (Pro) increased significantly with increasing drought stress. The genotypes Giza.843, Nubaria.2, and Nubaria.3 recorded the highest values of plant height, number of branches/plant, pods/plant, pods weight/plant, 100 seed weight, seed yield/plant, and seed yield/kg under drought stress. Similarly, the highest Pro was displayed by Giza.843 and Nubaria.3 under drought stress in both seasons. Furthermore, Giza.843, Nubaria.2, and Nubaria.3 genotypes had the highest values for most tolerant indices. Accordingly, these genotypes could be exploited in developing drought-tolerant and high-yielding faba bean genotypes in arid environments through breeding programs.