Effect of sowing year and seedbed type on yield and yield component in bambara groundnut (Vigna subterranea (L) Verdc) in woodland savannahs of Cote d’Ivoire

Bambara groundnut (Vigna subterranea) is one of the most promising food legumes in Africa, due to its agronomic and nutritional potential. To take advantage of these attributes, several research programmes gathering agronomic and genetic data are being implemented throughout Africa. In this context, the responses of yield and yield components to year sowing and seedbed type were tested in a three densities (13 900 plants ha−1, 62500 plants ha−1 and 250000 plants ha−1) field experiment using a bambara groundnut landrace with a semi-bunch growth habit. Three years sowing: 2005, 2006 and 2007 were coupled with two seedbed types – raised and flat. A factorial trial using a split-plot design with three replicates was set up to analyse seed yield and plant biomass, as well as nine yield components (Plant spread, Plant height, Number of leaves per plant, Number of pods per plants, Number of seeds per plant, Pods weight per plant, Pod fill ration, Seed harvest index). The seedbed type and year of experiment did not influence significantly the marketable yield and plant biomass (p> 0.05). This result has been attributed to the suitability of the amount and distribution of rainfall and temperature for the production of bambara groundnut at the target site. Based on the trend of yield response, cultivation of landraces of bambara groundnut characterized by a semi-bunch growth habit on flat seedbeds was suggested in woodland savannas of Côte d'Ivoire to enhance seeds yield and reduce labour.