Correlation and Path Coefficient Analysis of Yield and Yield Associated Traits in Small Onion

Genotypes of small onion were evaluated during 2014-2016 to determine the genotypic and phenotypic correlation along with their direct and indirect effects for bulb yield through path coefficient analysis in small onion. The experiment was conducted in a randomized block design (RBD) in two seasons with three replications at Soil and Water Management Research Institute, Kattuthottam, Thanjavur. The experiment result revealed that in most of the cases the genotypic correlation is higher than the corresponding phenotypic correlation values. This suggests that there inherit a strong relationship between the characters. In the present study, during summer season the bulb yield per hectare was positively and significantly associated with plant height at bulb formation stage (0.903), number of leaves at vegetative stage (0.813), neck thickness (0.886), neck diameter (0.868), equatorial diameter of bulb (0.91) and bulb weight (846). Higher number of leaves at vegetative stage is positively correlated and significant at polar diameter and equatorial diameter of bulb. Yield associating characters like neck thickness, neck diameter and polar diameter were also highly significant and positively correlated. During Kuruvai season, Bulb yield per hectare is highly significant and positively correlated with plant height at bulb formation stage (0.926) followed by bulb weight (0.96), neck thickness (0.889), equatorial diameter of bulb (0.873), polar diameter of bulb (0.852) and number of leaves at vegetative stage (0.834). Neck thickness expressed a highly significant and positive correlation co-efficient with polar and equatorial diameter & bulb weight. Polar and diameter is interrelated and positively correlated with equatorial diameter and bulb weight. Path coefficient of different characters contributing towards bulb yield during summer and kuruvai season bulb weight had the positive direct effect followed by equatorial diameter of the bulb, neck thickness, plant height at bulb formation stage and bulb filled stage and number of leaves at bulb formations stage. The improvement in marketable bulb yield per plant will be efficient, if the selection is based on bulb weight, neck thickness, plant height at bulb filled and bulb formation stage, polar diameter and equatorial diameter of bulb.