Phenotypic And Genotypic Correlations In Cowpea (Vijgna Unguiculata (L.) Walp)Phenotypic And Genotypic Correlations In Cowpea (Vijgna Unguiculata (L.) Walp)
Studies were carried out to determine phenotypic, genotypic and environmental correlations between number of pods/plant, number of seeds/plant, yield/ plant, days to flowering, number of seeds/pod and seed size using three intervarietal crosses of cowpea. Another objective was to determine heritability and mode of inheritance of each of the six characters. The experiments were conducted in 1984 and 1985 at Samaru (11° 11’N. 7° 38’E, altitude 636m). Three varieties, three F1 hybrids and their corresponding F2S were space-planted in 4 replications of a randomized complete block design (RCED) for the evaluations. Heritability estimates in the broad sense were very high for pods/plant, seeds/plant and seed size. There were positive and consistent correlations between pods/plant with seeds/plant and yield; seeds/ plant and yield/plant and yield/plant with seed size. The characters, pods/plant, seeds/plant and seed size were positively correlated with yield and exhibited transgressive segregation. This shows their value in indirect selection to improve yield, especially when using pure-line selection. Polygenic inheritance for these characters was indicated by unimodality in the F2 distribution of the crosses in both years. Complementary gene effects, as evidenced by skewness of all F2 distributions, were also indicated.