Evaluation of Drought Tolerance indices in Some Nigerian Bambara Groundnut (Vigna Subterranea L. Verdc.) Landraces

Abstract

Bambara Groundnut is the third most commonly eaten legume and a major source of protein for resourced poor farmers in Nigeria. In order to identify variations in drought tolerance indices of bambara groundnut landraces in Nigeria and to investigate the relationships between seed yield and drought tolerance indices, an experiment was carried out using 28 bambara groundnut landraces collected from farmers from four geo-political zones of Nigeria, as well as National Centre for Genetic Resources and Biotechnology (NACGRAB). The experiment was carried out during the cropping season of 2016 between July and October. The accessions were grown in a randomized complete block design in two treatments: Water stressed (T1) and non-water stressed (T2) with five replicates. Seed yield in respective non-stress (YP) and stressed (YS) treatments ranged from14-51 and 6-28 seeds per plant respectively. Stress susceptibility index (SSI), Stress Tolerance index (STI), Mean Productivity (MP), Geometric mean Productivity (GMP),Tolerance index(TOL), Harmonic mean(HM), Yield index(YI), Yield reduction (YR) and Yield stability index(YSI) ranged from 0.19- 1.69, 0.08- 1.80, 7.75 – 38.63, 7.65- 36.59, 1-37, 7.55-37.06, 0.47-2.11, 0.10 - 0.86 and 0.14 - 0.93 respectively. Pearson’s linear correlations between Ys and Yp, MP, GMP, STI, YSI, HM and YI were significantly positive (P<0.01). This experiment suggests the possibility of using MP, GMP, STI, HM and YI to improve Bambara groundnut yield under water stress and non- stressed environments.