DROUGHT STRESS EFFECTS ON THE GRAIN YIELD AMONG DIFFERENT BARLEY CULTIVARS

We examined commercial barley cultivars in two sequential growing season by including irrigation and rainfed conditions under a randomized complete block experimental design. There were positive and significant correlations between the yeild and either of the indices including Mean productivity (MP), Stress Tolerance Index (STI), Geometric Mean Productivity (GMP), Harmonic Mean Productivity (HMP), and Mean Relative Performance (MRP) in both irrigated and drought conditions. The PC1 and PC2 justified 94.86 and 94.44% of total variation in the first year and second year, respectively. According to 3-dimensional diagram and based on STI, genotypes 2, 3, and 8 in the first year and gentypes 4, 3, 8, and 2 in the second year were clustered together in group A, and therefore, called the most tolerant cultivars to drought stress.