Morphological and yield attributes of seven cowpea (Vigna unguiculata) genotypes

Abstract

Cowpea (Vigna unguiculata L. Walp) is among the most important food crops in the semi- and tropical regions of Africa and it’s a major source of proteins and other nutrients as well as income generation, not forgetting the fact that it’s a short season crop maturing early making it suitable for the changing climate of Uganda. The introduction of the new varieties into Uganda which are high yielding will help increase the cowpea yields in Uganda hence also increase the protein accessibility to resource poor people and improve income levels. Therefore, this study was aimed at evaluating the morphological characteristics, yield traits and correlation between the leaf area and the yield related traits of the seven cowpea varieties. There was also the hypothesis that variations in morphological traits can explain yield differences among cowpea genotypes. because large leaf area leads to increased yields in form of grain and fresh pod eaten as vegetables. The experiment was carried out at Makerere University Agricultural Research Institute Kabanyolo (MUARIK). Seven varieties were evaluated consisting of six genotypes from World Vegetable Centre (AVRDC) (V1060274, V1060276, V1060275, V04/124W, V05/23B and V1060277B) bred as vegetable cowpea and one local genotype (large black-eyed grain type) established in aRCBD with three replications. The seven genotypes evaluated showed high level of variations as measured using different plant growth characteristics. Significant differences (P < 0.05) between the genotypes for pod length, pod fresh weight, 100 seed fresh weight, pod dry weight and leaf area. Also, the correlation test between Cowpea leaf area was positively correlated with pod length, pod seed number, fresh pod weight, 100 seed fresh weight, pod dry weight, 100 seed dry weight. However, the results also showed a significant negative correlation between pod number and leaf area. The significant negative correlation observed between pod length and leaf area in this study implies that an attempt to bread for large leaf area would repress pod number. Therefore, based on these correlation results the hypothesis that leaf area leads to increased leaf yield for vegetables is accepted. Therefore, it is recommended that the breeders breed for reduced leaf area in order to achieve increased grain yield.