Effect of mycorrhization and soluble phosphate on growth and phosphorus supply of Voandzou [Vigna subterranea (L.) Verdc.]

Increasing yields in agriculture and management of soil fertility are becoming a major issue in view of the malnutrition problems. Tropical ferralitic soils are phosphorus (P)-deficient. The arbuscular mycorrhizal fungi (AMF) must form symbiotic associations with plants to enhance their hydro-mineral nutrition. The objective of this study wastoevaluate the effect of mycorhization on growth of Vigna subterranea. Seedlings of two landraces were inoculated with AMF composite (Gigaspora margarita and Acaulospora tuberculata). P was administered by Hoagland solution (0 and 1000 μMP_i). Two months after sowing, plants were harvested. The results show that, with or without phosphate, the number of nodules was three times (p<0.001) higher in mycorrhized plants compared to controls. Phosphate increased (p<0.001) the leaf P-content by 21 and 54% for the control and mycorrhized plants, respectively. Soluble phosphate did not affect the frequency and intensity of mycorhization. Soluble phosphate and mycorhizationsignificantly improve growth and leaf P-content.