Abstract:
Selection of genotypes with adequate combination of traits with high relationship and direct effect on yield at the appropriate density level increased the productivity in cowpea. The study was therefore undertaken to estimate genetic attributes of different cowpea genotypes and do path analysis of yield traits to yield to identify and select genotypes with adequate trait combination for improvement in yield. Correlation and path coefficient analysis were used to study yield and yield components. Six out of the nine traits measured in 2010 showed highly significant differences among the genotypes while all the traits were significantly different in the genotypes in 2011. The genotypic variances were lower than the phenotypic variances in all the traits indicating their interaction with the environment. Principal component analysis (PCA) could be used to delineate the genotypes into two groups. One group could be the bushy and dwarf types caused by high number of leaves and dwarfiness. The second group being the non-bushy and non-dwarf types caused by low number of leaves and high elongation of stems. Seed yield was positively and significantly correlated to number of leaves/plant, seed weight/pod, dry matter yield/plant in 2010 and number of pods/plant in 2011. Seed weight/pod and number of leaves/plant had positive direct effects of 0.611 and 0.549 on seed yield in 2010. Number of pods/plant, number of leaves/plant and pod length had positive direct effects of varying magnitude to seed yield (0.367, 0.087 and 0.016, respectively) in 2011. The consistent positive direct effect of number of leaves on yield in both years and high magnitude direct effect of seed weight in 2010 and number of pods/plant in 2011 suggests that the traits have high direct positive influence on seed yield. Hence, selection of genotypes with adequate combination of the three traits in combination with other traits will improve yield in cowpea at 40,000 plants/ha in the agro ecology as the traits are complementary in action
