Additive Main Effects and Multiplicative Interaction Analysis of Coffee Germplasms from Southern Ethiopia
Additive main effects and multiplicative interaction (AMMI) analysis is a recently recommended effective method to study the genotype by environment (GxE) interaction pattern of multi-environment varietal trials. This work deals with modeling and examining the GxE interaction pattern of the multi-environment trials of 43 genotypes and eight environments from Southern Ethiopia coffee (Coffea Arabica L.) collections using a randomized complete block design (RCBD) with four replications. The work further attempts to predict yield based on the ammi model and evaluate and recommend high performing and adaptable varieties. The AMMI model with the first two interaction principal component axes (AMMI2) is found to be appropriate and parsimonious for the data. Environments e5, e6, e7, e8 and e3 are found to be high potential environments, where genotypes having high-yield (greater than 14 qt/ha) and resistant to Coffee Berry Disease (CBD) are associated. Among the 43 genotypes, 1, 9, 2, 3, 32, 12 and 25 are found to have the best performance with 3, 32, 12 and 25 being highly stable. Among the high-yielding genotypes, 33, 4, 23, 34 and 27 are found to be highly unstable and particularly adapted to environments 5, 6, 7 and 3, respectively.