Assessment of stability and yield performance of onion (Allium cepa L.) genotypes across diverse Indian environments

Onion productivity in India is strongly influenced by genotype × environment interaction (GEI), complicating the identification of stable and high-yielding cultivars. Nineteen onion genotypes were evaluated in multi-environment trials across six diverse locations during two consecutive kharif seasons (2023-24), with locations treated as six distinct environments (E1-E6). Combined ANOVA revealed significant effects of genotypes, environments, and their interactions, indicating substantial GEI. AMMI analysis identified RO-1771 (G15), RO-1768 (G13), and RO-1774 (G17) as the most stable and high-yielding genotypes, while Junagadh (E3) was the most representative and discriminating environment. The first two principal components of the GGE biplot explained 83.86% of total GEI variation, efficiently capturing interaction patterns. Among the genotypes, 'Bhima Dark Red' (G18) consistently showed superior yield and stability, followed by RO-1768 and RO-1774, which also demonstrated broad adaptability. Junagadh was identified as an ideal site for both cultivation and varietal testing. Collectively, the GGE and AMMI analyses revealed that Bhima Dark Red (G18), RO-1768 (G13), and RO-1774 (G17) combined high yield with stability across multiple environments. These findings provide valuable guidance for onion breeding programs and support the development of cultivars adapted to diverse Indian agro-climatic conditions.