The present study was conducted on 18 food barley genotypes across 11 environments in randomized complete block design with four replications in Bale highlands of Southeastern Ethiopia from 2001-2003 Bona cropping season with the objective of evaluating yield performance of barley genotypes and identification of mega environments. GGE (i.e., G = genotype and GE = genotype by environment, interaction) biplot methodology was used for graphical display of yield data after subjecting the genotypic means of each environment to GGE Biplot software. The analysis of variance revealed that environment accounted for 76.7% of the total variation while G and GE-interaction explained 2.3 and 9.7%, respectively. The first two principal components (PC1 and PC2) were used to display a two-dimensional GGE biplot. Thus, genotypic PC1 scores >0 classified the high yielding genotypes while PC1 scores <0 identified low yielding genotypes. Unlike genotypic PC1, genotypic PC2, scores near zero showed stable genotypes whereas large PC2 scores discriminated the unstable ones. The environmental PC1 were related to cross over type of GEI while PC2 scores were associated with non cross over GEI. Genotypes (A, G, E, H, L, B and R) were found to be desirable in high yielding and stability. The 11 test environments in the highlands of Bale were divided in to two distinct mega environments (Mega-1 and 2). Mega-1 constituted environments such as E1 (Sinana-01), E2 (Gassara-01), E3 (Sinja-01), E4 (Sinana-02), E5 (Gassara-02), E6 (Sinja-02), E8 (Sinana-03), E9 (Gassara-03) and E10 (Sinja-03) while Biftu cultivar being the best winner, on the other hand, Mega-2 contained two environments, E7 (Upper Dinsho-02) and E11 (Upper Dinsho-03) while shage cultivar being the best winner. The results of this study indicated that breeding for specific adaptation should be taken as a breeding strategy in Bale highlands to exploit positive GEI to increase production and productivity of barley.
Zerihun Jalata , 2011. GGE-biplot Analysis of Multi-environment Yield Trials of Barley (Hordeium vulgare L.) Genotypes in Southeastern Ethiopia Highlands. International Journal of Plant Breeding and Genetics, 5: 59-75.