Published online by Cambridge University Press: 15 November 2003
Introduction. Arbuscular Mycorrhizal Fungi (AMF) can promote host growth and, among other benefits, alleviate the stress produced by transplanting seedlings from the nursery to the field. The objective of this work was to evaluate the effect of the amount of AMF inoculum on growth of Hancornia speciosa (Mangaba tree). Materials and methods. A greenhouse experiment was performed using a randomized experimental design in a factorial arrangement of 3 × 3 corresponding to: two AMF (Gigaspora albida Schenck & Smith andGlomus etunicatum Becker & Gerdeman) treatments plus one control with plants without AMF three inoculum densities [(50, 100 and 300) spores per plant], with five replicates, in a methyl bromide sterilized soil. Results. After 120 d, seedlings associated with G. albida had greater height, shoot diameter and dry biomass of the aerial part and leaf area than those associated with G. tunicatum, independent of inoculum density. G. etunicatum did not influence growth of H. speciosa. Positive correlations occurred between plant growth parameters and root colonization promoted by G. albida. Regression analysis showed interaction between the inoculum density of G. albida and plant growth parameters. Discussion and conclusion. Increments in growth of H. speciosa can be obtained with inoculation of approximately 180 spores of G. albida per plant, which could reduce the necessary period of time for the transplanting of seedlings from the nursery to the field.