عنوان مقاله [English]
In order to study the response of sesame cultivar to irrigation interruption in different phenological, An experiment was conducted as slit-plots arranged in a randomized completed block design with three replications at Mayamey area (Shahrood city, Semnan Province) in a private farm in 2015-2016. The main plot was including irrigation cut-off time (vegetative, flowering and seed filling stages) and subplot including three sesame cultivars (Darab, Oltan and Dashtestan). The results showed that Oltan cultivar was more stable in drought stress due to irrigation cut-off compared to other cultivars. The response of Darab and Dashtestan cultivars to irrigation cut-off was different both in terms of grain yield and oil yield. In Darab cultivar, irrigation cut-off in vegetative stage and in Dashtestan cultivar, in seed filling stage had the most negative effect. There was no statistically significant difference between Oltan and Darab cultivars in terms of yield components such as number of capsules per plant, number of seeds per capsule and 1000-seed weight, but Dashtestan cultivar produced less yield components. The greatest decrease in the number of lateral branches and the number of seeds per capsule was observed in irrigation cut-off at vegetative and seed filling stage, respectively. Other yield components were not affected by irrigation cut-off time. overall, the results showed that Oltan cultivar has a higher relative resistance to stress at different stages. Therefore, this cultivar is recommended for this region and similar situations.