Identification of selection indices for the yield enhancement in cowpea (Vigna unguiculata (L.) Walp.) under sodic condition

Abstract

The experiment was conducted at sodic soils to determine the relationship and degree of direct and indirect effects of yield and yield contributing traits in 57 cowpea accessions along with checks CO (CP) 7, VBN 1 and VBN 3. The association analysis showed that clusters number per plant, pod numbers per cluster, length of the pod, seeds per pod and hundred seed weight were positively correlated with seed yield. Path analysis indicated that the number of clusters per plant revealed a highly positive direct effect on single plant yield at genotypic level followed by pod length, pods number per cluster and seeds per pod. Principal Component Analysis (PCA) revealed first four PCs together contributed 67.33 per cent of variability. A total of 12 genotypes occupied the first quadrant showed better performance for five characters namely 100 seed weight, seed yield per plant, the number of clusters per plant, the number of pods per cluster and plant height. These selected genotypes namely IC 201075, EC 101989, EC 724750, EC 725166, CO 7, EC 724707, EC 121879, EC 101940, EC 101913, EC 724767, EC 107181 and EC 101928 could be used as donors or elite genotypes in cowpea yield improvement programmes.

Keywords

• correlation
• cowpea
• path analysis
• pca
• sodicity