Genetic variability appraisal and inter-relationships between different quantitative and qualitative traits in diverse late kharif onion (Allium cepa L.) genotypes

Onion (Allium cepa L.) is an important vegetable and spices commercially cultivated across the globe. The present investigation was carried out in late kharif season to evaluate fifteen onion genotypes for elucidating the genetic variability, interrelationship between yield attributing and quality traits as well as their effect on onion bulb yield. The genotypes were evaluated following Randomized Block Design maintaining three replications at District Seed Farm of Bidhan Chandra Krishi Viswavidyalaya consecutively over 2 years. The result showed presence of substantial genetic variability for most of the traits studied among the onion genotypes. High heritability along with high genetic advance over percentage of mean was exhibited by most of the traits except days to maturity, thus revealed preponderance of additive gene action. Correlation study revealed that the total bulb yield was positively and significantly correlated with polar diameter (r = 0.467*), equatorial diameter (r = 0.472*) and bulb weight (r = 0.825**). The neck diameter, days to maturity and quality traits like total soluble solid, dry matter, pyruvic acid content exhibited negative association with bulb yield, indicating the perplexity in simultaneous improvement of these quality traits with yield. The result revealed simple selection of traits viz. average bulb weight, polar diameter and equatorial diameter can be more effective towards development of superior late kharif onion genotypes.