To determine yield stability and to evaluate genotype interaction with environment interaction, 18 genotype of barley
(Hordeum vulgare L.) and a control group were evaluated in a randomized complete block design with 4 replications in
3 successive years (1997-2000) at 10 research stations. Simple and combined analysis of variance revealed significant
genetic differences between yield genotypes for grain yield.
The results of combined analysis of variance indicated that genotypic and genotype were significant through
interaction with environment. Therefore, different stability parameters including, environmental variance (S2 i),
environmental coefficient of variation (C. Vi), mean of variance of interaction (θi ), interaction variance (θi),
equivalence (W2i), stability variance «(σ2i ), linear regression coefficient (bi, βi), mean of squares of deviation from
regression (S2 di) and years within location MS for a genotype, averaging over all locations (MSy/l)were determined.
Based on all the stability parameters, genotype 18 was known-as the most stable one and genotypes 17 and 11 ranked
lower. Genotype 5 with the highest yield -was known to be the most adaptable one at fertile environments and is
recommended for these locations. In addition, genotype 9 with good yield and low yield variance (1.58) and regression
coefficient of less than 1 is suggested for unfertile locations.