Statistical Methods to Study Adaptability of Barley Genotypes Evaluated Under Multi Environment Trials

Genotypes G5, G8, G3, G21 and G18 had achieved higher yields besides b_i > 1.0. G21 and G3 identified as appropriate one, because had higher yield value than the mean, bi values near 1.0 and low S²_di. Lower values (W²_i) resulted for G12, G5, G2, G21 while higher for G5, G3 and G14. Genotypes G12 followed by G2, G20, and G7 had the smallest environmental variance (S²_xi). Smaller values of (CV_i) considered G12, G2, G20, and G10 of stable performance. α² _i measure pointed out G12, G7 and G2 with smallest values. Desirable lower P_i values reflected by G18, G5, G21, and G4 while GAI values identified G18, G11, G4 G10 as desirable genotypes. S_i ⁽¹⁾ and S_i⁽²⁾ showed lower values of G12, G2 and G7 genotypes. Significant tests of S_i ⁽¹⁾ and S_i⁽²⁾ proved the highly significant difference in ranks among the 21 genotypes grown in 8 environments. Genotypes G12, G2, and G7 had the lower S_i⁽³⁾ and S_i⁽⁶⁾ values. Yield of genotypes had significant negative correlation with bi, S_i⁽²⁾, S_i⁽³⁾, S_i⁽⁶⁾, NP_i ⁽²⁾, NP_i⁽³⁾, NP_i⁽⁴⁾ and significant positive correlation with GAI, P_i and Rank Sum. Hierarchical cluster analysis classified genotypes into three clusters as largest cluster included genotypes with more than average yield along with high yielders G18, G11, G3, G5, G21 and unstable performance indicated by non parametric measures. Biplot analysis while considering first two significant principal components grouped the parametric and non parametric measures into four groups. The smaller group consisted of b_i and S² _di and adjacent to group of non parametric measures S_i⁽²⁾, S_i⁽⁶⁾, NP_i⁽²⁾, NP_i⁽³⁾ and NP_i⁽⁴⁾.