GGE Biplot Analysis of Multi-environment Yield Trials of Durum Wheat (Triticum turgidum Desf.) Genotypes in North Western Ethiopia

This experiment was done to identify the most stable durum wheat genotype(s) as well as desirable environment(s) for durum wheat (Triticum turgidum var. durum Desf.) research in north western Ethiopia. Grain yield performance of the tested genotypes were evaluated at four locations (Adet, Debretabor, Gaint and Simada) using randomized complete block design with three replication for two consecutive years (2010 and 2011). Combined analysis of variance showed that grain yield was significantly affected by environments (E), genotypes (G) and GE interactions. The first two principal components (PC1 and PC2) were used to create a two-dimensional GGE biplot and explained 45.67% and 32.71% of the total sums of squares of GE interaction, respectively. The ‘which-won-where’ feature of the GGE biplot suggested that the existence of three durum wheat mega-environments in north western Ethiopia. Among the testing environments, six environments such as E1, E2, E4, E5, E6 and E8 were included inside mega-environment one (ME1) while the remaining two testing environments, E3 and E7 were included inside mega–environment two (ME2) and mega-environment three (ME3), respectively. The GGE biplot also identified G7, G5 and G10 as winning genotypes at ME1 whereas G11 was identified as a high yielding genotype in both ME2 and ME3. According to the average environment coordination (AEC) views of the GGE-biplot, genotype G10 was identified as the most stable and high yielding genotype. In addition, G1 and G6 also showed better stability performance among the high yielding genotypes whereas genotype G12 was identified as the least stable and low yielding genotype. Therefore, genotypes G10, G1 and G6 were recommended for commercial production in most wheat growing areas of north western Ethiopia.