Genotype by Environment Interaction and Yield Stability of Coffee (Coffea arabica L.) Genotypes Evaluated in Western Ethiopia

ABSTRACT The performance of genotypes under diverse environments can be used to determine their adaptability and stability. However, information on the performance of coffee genotypes in various environmental conditions is limited. Thus, this study’s objectives were to estimate genotype by environment interaction (GEI), evaluate the mean performance and stability of 16 fruity flavored coffee genotypes in eight specialty coffee growing environments in western Ethiopia, and assess the magnitude of correlations among different stability parameters. The experiment was laid out in a randomized complete block design (RCBD) with two replications. For coffee yield, data were recorded and a combined analysis of variance and stability analysis were performed. Additive main effect and multiplicative interaction (AMMI) analysis revealed that genotypes, environments, and GEI showed highly significant differences (P < .0.01) for coffee bean yield. AMMI analysis also revealed that 73.2% of the GEI sum of squares for coffee bean yield was accounted for by the first three interaction principal component axes (IPCA). The standard check variety G16 (Menesibu), G3(W54/99), and G10 (W107/99) gave the highest average yields of 1537, 1458 and 1375 kg of clean coffee per hectare across environments, respectively. Despite no genotypes consistently performing well across environments due to the high GEI, G1 (W13/99) and G5 (W54/99) were relatively stable. Therefore, these were recommended as useful genetic resources for breeding of high-yielding genotypes. However, since all the genotypes gave a mean yield below the standard check variety, additional genotypes should be tested in more environments to develop stable and high-yielding coffee varieties. Graphical abstract