EFFECT OF WATER STRESS ON SEED QUALITY AND ASSOCIATED TRAITS AND COST BENEFIT ANALYSIS FOR SEED PRODUCTION OF BAMBARA GROUNDNUT (Vigna subterranea (L.) Verdc).
Bambara groundnut is recognized as a drought tolerant crop which can adjust to a wide range of conditions and still produce yields. It is an underutilized legume which can be used to attain food and nutrition security. The study was conducted in pots under a rain shelter from December, 2018 to April, 2019 at the West Africa Centre for Crop Improvement (WACCI) field to assess the effect of water stress on seed quality (viability, vigour and seed size) and yield, and a field trial to estimate the cost and benefits involved in the production of Bambara groundnut seeds.
Two accessions; GHL015 and GHS091 were subjected to three water levels of 20-30%, 50-60% and ≥80% available soil moisture after seedling establishment (35 days after planting) till maturity. Plant growth and physiological measurements taken included leaf area, leaf number, chlorophyll content and chlorophyll fluorescence. Seed quality measurements analyzed were, standard germination test, root:shoot ratio, seedling length, root length, shoot length, seedling fresh weight, seedling dry weight and seed weight. Yield and its components measured included seed yield, number of pods per plant, shelling percentage, individual pod weight and individual seed weight.
Root:shoot ratio, vigour index I and II showed similar results at 20-30% and 50-60% available soil
moisture and were significantly lower (p < 0.05) than plants grown under ≥80%available soil moisture. Germination percentage and seed yield showed similar results where ≥80% available soil moisture had the greatest value and 20-30% available soil moisture had the lowest value. It also showed that the seeds from stressed plants were adversely affected by reduction in seed size and viability. In determining the preferable soil moisture content for yield and good quality Bambara groundnut seeds, it is necessary to maintain optimum water level in as much as Bambara groundnut is a drought tolerant crop. It is profitable to venture into Bambara groundnut seed production business as the estimated profit was 43%.