Correlation studies in cowpea (Vigna unguiculata L.)

Abstract

A field experiment was conducted to estimate the genetic variability and genetic divergence in Cowpea. Thirty-One genotypes were sown in a randomized block design with two replications, during kharif 2018 at Research farm, Department of Agricultural Botany, V.N.M.K.V. Parbhani. The objective of the experiment was to identify divergent to be used as donor parents in hybridization programmes. The observations were recorded on 12 characters viz., Plant height (cm), number of primary branches per plant, days to 50% flowering, number of pods per plant, number of seeds per pod, mean pod weight (g), pod length (cm), pod width (cm), days to first pod harvest, 100 seed weight (g), pod yield per plant (gm), pod yield per hectare (Kg). Analysis of variance and mean performance for pod yield and its components revealed significant differences among all the genotypes for all the characters there by indicating presence of variability in genotypes studied. From correlation studies, it was observed that pod yield per plant had exhibited highly significant positive association with number of pods per plants, number of primary branches per plants, plant height and number of seeds per pod. Whereas maximum significant and negative correlation was shown by days to first pod harvest. In the present studies, the characters plant height (cm), number of primary branches per plant, days to 50% flowering, number of seeds per pod, number of pods per plant and pod length showed positive and significant correlation with pod yield per plant. Pod yield per hectare recorded high positive significant correlation with number of primary branches per plant (0.6115rg, 0.4548rp) at 1% level of significance. It also showed positive significant correlation with number of pods per plant (0.2321rg, 0.2595rp) and number of seeds per pod (0.3760rg, 0.2984rp) at both 5% and 1% levels of significance. These results are supported by Patel et al. (2016). The magnitude of genotypic correlation was higher than phenotypic correlation for all the traits that indicated inherent association between various characters.