The effect of arbuscular mycorrhizal fungi (AMF) and addition of phosphorus on seedling growth of Prosopis juliflora in sterilized and unsterilized soils was followed during 100 days. A red-yellow podzolic soil, pH of 4.7 and 2 mg Pdm-3, was used. The experiment was carried in a completely randomized design, with four replicates, and factorial arrangement of 2 soil conditions (sterilized and unsterilized) × 3 P levels (0, 50 and 100 kg P.ha-1) × 2 mycorrhizal treatments (with and without AMF). In unsterilized soil, only the collar diameter increased with inoculation; increases in height, number of leaves, and dry matter (DM) production perhaps were due to soil P fertilization. In sterilized soil, inoculation resulted in increases in height, number of leaves, collar diameter and DM production with or without P additions (P0 and P50), in relation to the non-inoculated treatment. A further increase in P (P100) cancelled the effect of the inoculation. Colonization and spore production was enhanced with P additions. Prosopis juliflora could be considered as mycotrophic facultative, since it presents growth response to both AMF inoculation and P supply.
seedling production; AMF; soil sterilization
