Rhizobial biofertilizers and Bambara groundnut (Vigna subterranea L. Verdcourt)

Valorization of interaction between indigenous rhizobia and local leguminous varieties is of great economic interest due to its function in enhancing agricultural productivity. The present study aims to evaluate the effect of biofertilizers based on Rhizobium on the productivity of three Bambara groundnut varieties in two semiarid Agro Ecological Zones (AEZ) of Benin (AEZ 4: West Atacora zone and AEZ 5: Cotton zone of the Centre Benin). Four inoculation treatments i.e., control uninoculated, Rhizobium strains LMSEM312, LMSEM338, USDA110 were tested on three Bambara groundnut varieties (Variety 1: Azigokouiwéwékpè; Variety 2: Azigokouivovo; Variety 3: Azigokouiwéwékpoguè) in a Randomized Complete Block design. Results revealed that the different Rhizobia strains improved nodulation and yield parameters of the three Bambara groundnut varieties. Among the tested strains, LMSEM338 induced the highest nodules number (30 nodules per plant) and nodule dry weight (0.34 g plant-1) for the three Bambara varieties in the AEZ 4. In the AEZ 5, the best nodulation was reported on variety 1 inoculated with strain LMSEM312 (28 nodules which weighted 0.31 g). In the AEZ 4, grain yield ranged between 616.63 kg ha-1 (Variety 1 uninoculated) and 1918.64 kg ha-1 (variety 3 inoculated with strain LMSEM 338). In the AEZ 5, grain yield ranged between 518.13 kg ha-1 (variety 1 uninoculated) and 1596.89 kg ha-1 (variety 1 inoculated with strain LMSEM312). These strains could be used as a potent candidate for biofertilizer production to get sustainable yield of Bambara groundnut on marginal soils with minimum inputs.