Abstract

Garlic is the major bulb crop next to onion in Ethiopia. Lack of stable and high yielding cultivars is one of the major problems for production and productivity of garlic in the country. Identification of adaptable, stable and high yielding genotypes under varying environmental conditions prior to release as a cultivar is the first steps for plant breeding. Therefore, developing high yielding and stable varieties is the primary objective of garlic improvement in this country. Nine garlic genotypes were evaluated to study their adaptability and stability in eight environments of Tigray region, northern Ethiopia. The experiment was carried out in randomized complete block design with three replications in four locations over two years. In this study, additive main effects and multiplicative interaction (AMMI) and genotype by environment interaction (GGE) biplot analyses were used in the evaluation of test environments and genotypes. The AMMI analysis showed that the effects of genotype, environment and genotype × environment interactions were significant (P<0.01) on bulb yield. AMMI evaluation confirmed that the three main components accounted for 89.8% of the whole genotype by environment interaction. The which-won-where view of the GGE biplot showed that environments used for this study grouped in to two mega-environments, with two different winning genotypes G9 and G7. Both AMMI and GGE biplot analysis identified promising genotypes. Genotype G9 (Bora-1/16) had the highest average yield performance and stability compared to other cultivars and should be used in breeding programs for new garlic variety development.

Key words: Additive main effects and multiplicative interaction (AMMI), bulb yield, garlic, genotype by environment interaction (GGE) biplot, stability analysis.