Trait-Specific Assessment and Classification of Kharif Onion (Allium cepa L.) Varieties for Enhanced Bulb Yield and Quality

Kharif onion plays a critical role in stabilizing onion supply and prices in India during the lean period between rabi and late kharif harvests. However, its cultivation is constrained by variable monsoon conditions, waterlogging stress and limited varietal adaptation. This study evaluated nine kharif adapted onion genotypes across two seasons (2023–2024) at ICAR-DOGR, Pune, assessing fifteen agro-morphological and nine biochemical traits. Combined ANOVA showed significant effects of genotype, year and their interaction for most traits. BDR, Bhima Super and B-780 recorded the highest yields (marketable: 29.99–30.84 t/ha; total: 33.30-35.88 t/ha) with larger bulb sizes, while Bhima Shweta and Bhima Red matured early but yielded less. Bhima Raj and BDR showed the highest phenolic content and antioxidant activity; B-780 and Bhima Shubhra had the highest sugar contents. Strong positive correlations were observed between total yield, marketable yield and average bulb weight (r = 0.78–0.95) and between total phenols and antioxidant activity (r = 0.87). Cluster and PCA analyses grouped genotypes into three distinct clusters based on yield and quality traits. These findings identify genotypes combining both high yield and enhanced biochemical quality, offering valuable parents for kharif onion breeding aimed at improving bulb yield, storability and health-promoting attributes.