Variability studies in Rabi onion (Allium cepa var cepa L) for yield and yield contributing traits

The present study was aimed at investigating the yield and yield contributing traits in onion in order to generate information regarding the extent of genetic variability, heritability and genetic advance. The experiment was laid under randomized block design with three replications at college of Horticulture, Dr Panjabrao Deshmukh Krishi Vidyapeeth, Akola, Maharashtra during Rabi season 2012–13 to investigate the genetic variability among 21 genotypes. High degree of variation was observed for all the characters studied. The difference between phenotypic (PCV) and genotypic (GCV) coefficient of variation was found to be narrow for most of the traits except bulb weight and neck thickness. The GCV ranged from 4.82 (bulb diameter) to 14.60 per cent (bulb weight) while PCV ranged from 5.72 (number of marketable bulbs per plot) to 17.29 per cent (bulb weight) for the various characters studied. The high estimates of heritability were found for all the characters studied. Expected genetic advance over mean was observed high for the characters viz yield per plot, bulb weight and number of marketable bulbs per plot. These characters are therefore governed by additive gene effects. Selection on the basis of these characters will be more useful for the improvement of this crop towards attaining higher yield.