Comparison of qualitative and quantitative traits and tolerance indices of sunflower cultivars under drought stress and non-stress conditions

In order to study the effect of drought stress on qualitative and quantitative traits of sunflower cultivars and use of drought tolerance stress to determine the most tolerant cultivar to drought stress، this experiment was conducted on six cultivars of sunflower under two irrigation regimes (normal irrigation and drought stress) at agricultural and natural resources center of Yazd in 2010. The experiment was carried out in split plot in randomized complete block design with three replications. Results showed that effect of drought stress was significant on all of the characteristics and cultivars. The highest seed yield was produced by Azargol cultivar (1874 kg/ha) and lowest seed yield was produced by super grows (757 kg/ha) in drought stress condition. Therefore results indicated that Azargol is the most resistant cultivar to drought stress and Supergrow is the most sensitive cultivar to drought stress.