Evaluation of eight bambara groundnut (Vigna subterranea (L.) Verdcourt) accessions for agronomic characters and proximate composition in Uyo, Akwa Ibom State, Nigeria

Bambara groundnut (Vigna subterranea [L.] Verdc.) is a valuable but underutilised legume crop grown in sub-Saharan Africa. The objective of this study was to evaluate the yield and yield components of eight Bambara groundnut accessions obtained from the National Root Crops Research Institute in Umudike, Nigeria.  The experiment was conducted at the Teaching and Research farm of the University of Uyo, Uyo Southern Nigeria during the 2021 cropping seasons, using a randomised complete block design with three replications. Growth, yield and nutritional parameters were collected and subjected to analysis of variance, correlation and principal component analysis. Plant height, number of leaves, and leaf area were all significantly different (P≤0.05) among the accessions three months after planting. Number of pods per plant, seed weight, and 100-seed weight differed significantly (P≤0.05). Caly PSC (2853 kg/ha), Caly SK 46 (2803 kg/ha), Zeina (2538 kg/ha), and BNT (2488 kg/ha) were the top yielders among the accessions. Yields of Bambara groundnut differ significantly (P≤0.05) between accessions studied, ranging from 1624.67 kg/ha to 2853.33 kg/ha. Principal component (PC) analysis identified eight influential components, two of which, PC1 and PC3, contributed 27% and 17% of the total variation, respectively. In this study, the correlation analysis revealed that plant height and petiole length, plant height and number of seeds per plot were all negatively correlated. The leaf area and the number of pods per plot, the number of seeds per pod and the fibre content, the leaf area and seed weight, and the plant height and seed weight were all noted positively correlated. The nutritive value of the eight Bambara groundnut accessions varied significantly (P≤0.05). The mean protein levels of eight Bambara nut accessions studied ranged from 18.82 to 20.39%. Findings from this study clearly indicate that Bambara groundnut is suitable for production in Uyo, Akwa Ibom State. Thus, high yielding accessions identified in this study are recommended for increased production in Akwa Ibom State of Nigeria.