Investigation of grain yield and some agronomic traits in barley under normal and rain-fed condition

In order to study drought tolerance in barley, two separate experiments were conducted in the form of a randomized complete block design with three replications under normal humidity and rainfed conditions in the research farm of Islamic Azad University, Sanandaj branch in the 2013-2014 crop year. Traits: Grain yield per unit area, day to spike, day to flowering, day to physiological maturity, number of fertile tillers, plant height, peduncle length, spike length, awn length, number of Grains per main spike, plant weight and spike weight were evaluated.The results of analysis of variance under normal and stress conditions indicated a significant difference between cultivars in terms of most of the studied traits.In normal conditions, harvest index and peduncle length and in stress conditions, harvest index and 1000-grain weight showed a positive and significant correlation with grain yield. Stepwise regression analysis showed that under normal moisture conditions, plant weight and peduncle length, and in dryland conditions, plant weight, spike length, day to flowering and day to spike are the most influential traits on grain yield in barley, respectively. Drought tolerance indices of MP, GMP, STI and HM were identified as efficient indices in detecting drought tolerant genotypes with high grain yield potential due to positive and significant correlations with Yp and Ys in barley. Kavir and Zarjoo cultivars with high values of MP, GMP, STI, HM, Yp and Ys indices were recognized as the most drought tolerant cultivars.