Evaluation of sesame genotypes for agronomic traits and stress indices grown under different irrigation treatments

Abstract

AbstractSesame (Sesamum indicum L.) is among the oldest cultivated oilseed crops and is regarded as the “queen of oil seeds” because of its oil quality. Since sesame is cultivated in harsh environments, its seed yield is greatly affected by adverse conditions, such as drought. Therefore, we undertook a 2‐yr experiment to understand the effects of deficit irrigation on yield, yield components, oil percentage, water use efficiency, and stress indices of six sesame genotypes. The experiment was conducted at Seed and Plant Improvement Institute, Karaj, located in the semi‐arid region of Iran, during the 2017 and 2018 growing seasons. Deficit irrigation was induced by irrigating after 80% available water depletion, and irrigating after 40% available water depletion was considered to be normal irrigation. Among the genotypes, Oltan and USA‐ns‐96 produced the maximum seed and oil yield. Stress indices analysis revealed that the Sudan‐94 genotype was the most tolerant to deficit irrigation, and the Dashtestan‐2 genotype was the most sensitive. In addition, the Sudan‐94, USA‐ns‐96, and Oltan genotypes showed the highest yield stability index and relative stress index. Regarding drought tolerance, the Sudan‐94 genotype performed the best with minimum reduction in seed yield and other agronomic traits. Overall, these results suggest that the Sudan‐94 genotype is the most drought‐tolerant genotype with the maximum yield stability. Moreover, this study highlights the possibility of using Sudan‐94 genotype in future breeding programs.