Correlation Coefficient and Path Analysis of yield and its components for seven cowpea genotypes (Vigna unguiculata L.) and its F1 hybrids

Abstract

The present investigation was carried out in the experimental field of Technical College of Agriculture, University of Halabja, in 2022 summer season to determine correlation coefficient and path analysis results for yield and its components in cowpea. Twenty-eight genotypes of cowpea used in the Completely Randomized Block Design (CRBD) in three replicates to evaluate ten quantitative characters included pods yield /plant, number of pods /plant, pod length, the number of seeds /pod, the number of branches /plant, 100 grains weight, plant height, average harvest duration, grain index and grain yield /plant. Among the studied traits, pods yield /plant, pod length, the number of pods /plant, 100 grains weight, number of branches /plant, the plant height and average harvest duration showed highly significant and positively association to grain yield /plant with 0.922, 0.432, 0.787, 0.394, 0.309, 0.515 and 0.560 respectively. Pods yield /plant, with 0.785 recorded the highest value of positive direct effect on the grain yield, and followed by the character number of pods /plant with 0.142. The characters number of brunches /plant with -0.060 showed the maximum negative value of direct effect in total grain yield. The pods yield /plant via the number of pods per plant confirmed the highest value of positive indirect effect with 0.654, and the pods yield /plant via the average harvest duration followed it with the value of 0.484. The highest value of negative indirect effect was -0.033 recorded by the average harvest duration via the character number of brunches /plant. The results of those character association work aid in understanding how various characters contribute to overall yield, breeders can use this knowledge to increase yield by increasing yield-contributing traits directly or indirectly.