Discriminant function method of selection in vegetable cowpea [Vigna unguiculata (L.) Walp.]

Abstract

Fifty four diverse genotypes of vegetable cowpea were evaluated for fourteen characters in order to construct selection indices. The characters, which had desirable correlation as well as moderate to high direct effect on green pod yield per plant were considered as selection index criterion. The green pod yield per plant (X1) along with its four components viz., number of pods per plant, number of clusters per plant, ten pod weight and pod length were utilized for the construction of selection indices. The discriminant function had higher genetic gain and relative efficiency over straight selection for green pod yield per plant alone. Among all the 31 selection indices (Table 1.2), the index based on five characters viz., green pod yield per plant, number of pods per plant, number of clusters per plant, ten pod weight and pod length (X1+X2+X3+X4+X5) possessed the highest genetic gain and relative efficiency (89.89g and 140.62%) as compared to straight selection for green pod yield per plant followed by four characters viz green pod yield per plant, number of pods per plant, and ten pod weight and pod length (X1+X2+X4+X5) and green pod yield per plant, number of pods per plant, and number of cluster per plant and ten pod weight (X1+X2+X3+X4) possessed the highest genetic gain and relative efficiency (88.68g and 138.84%) and (88.43 g and 138.46%) respectively.