Initial growth, nutrition, and quality of Senegalia polyphylla plants inoculated with arbuscular mycorrhizal fungi under phosphate fertilization

Knowing the nutritional needs of these plants, the interactions that favor their growth and survival in the field, such as inoculation with arbuscular mycorrhizal fungi (AMF), are essential to subsidize tropical forestry. The present study aimed to evaluate the effect of applying phosphorus (P) and inoculation with AMF on growth, biomass production, quality, and nutrition in seedlings of Senegalia polyphylla. The experiment was carried out in a completely randomized design, in a 5 x 3 factorial scheme, with five doses of P (0, 50, 100, 200, and 400 mg kg(-1)), and three microbiological treatments (inoculated with Rhizophagus claru, Gigaspora margarita, and control without inoculation). At 120 days after transplanting (DAT), there were evaluated the rate of root mycorrhizal colonization (MC), plant shoot height (H), stem diameter (D), N and P content in the shoot of the plants (NC and PC, respectively), dry matter mass of shoot, roots, and total (DMS, DMR, and DMT, respectively). Those variables allowed the calculation of Dickson's Quality Index (DQI) and mycorrhizal dependence (MD). Phosphate fertilization influenced all evaluated characteristics of S. polyphylla (p < 0.01), while inoculation with AMF alone influenced only DMS, DMT, DQI, and PC. Plants inoculated with R. clarum and G. margarita showed MC ranging from 12.5 to 55%. At the dose of 0 mg kg(-1) of P, seedlings of S. polyphylla showed high MD. The inoculation with AMF and the application of P are indicated to obtain seedlings of S. polyphylla.