Association studies in cowpea (Vigna unguiculata L.)

Field experiment was conducted in the kharif 2012 to estimate genetic variability, heritability, correlation and path co-efficient studies. The material was planted in Randomized Block Design (RBD) with three replications and sixty genotypes of cowpea were evaluated for eleven morphological traits viz., Plant height, leaf length, leaf width, number of branches, stem girth, number of leaves, number of pods, seeds per pod, pod weight, 100 seed weight and seed yield per plant. The high range of variability was observed for plant height (117.2–261.5), number of leaves (194–568), pod weight (10–105) and seed yield per plant (3.12- 225.05) while rest of the traits showed medium range of variability. The highest value of PCV (Phenotypic coefficient of variation) and GCV (Genotypic coefficient of variation) were recorded for seed yield per plant (108.91, 108.86) followed by number of pods (66.12, 65.05), pod weight (49.1, 48.37) and 100- seed weight (28.88, 27.92). In general, the genotypic correlation co-efficients were higher in magnitude than the phenotypic correlation co-efficients. Seed yield per plant was highly significantly and positively correlated with number of pods per plant (0.92, 0.90), pod weight (0.90, 0.89), 100-seed weight (0.57, 0.55), leaf length (0.56, 0.90), leaf width (0.27, 0.11) and seeds/pod (0.22, 0.14), respectively. Genotypes CL 2, CL 22 and CL 40 were found to be free from mosaic.