Production of mycorrhized sweet passion fruit seedlings in disinfected and phosphorus fertilized soil

The objective of this work was to identify the required P dose and efficient arbuscular mycorrhizal fungi (AMF) to promote growth of seedlings of sweet passion fruit. An experiment was carried out at the greenhouse, in a randomized design with a factorial 2x4x4: two soil conditions (disinfected or not), four treatments of inoculation (inoculated or not with Gigaspora albida, Scutellospora heterogama and native AMF from the rhizosphere of sweet passion fruit plants), four doses of available P (Mehlich-1) (8 - natural soil -, 12, 16 and 20 mg dm(-3)), with four replicates. Native AMF promoted growth of seedlings after 30 days of inoculation, while other fungi stimulated plant development after 45 days. Quadratic models indicated maximum values of plant height in soil, with P values estimated between 15.40 and 16.07 mg dm(-3) in disinfected soil and 14.85 and 15.60 mg dm(-3) in non disinfected soil, obtained in treatments with S. heterogama and G albida, respectively. Higher spores density and mycorrhizal colonization were observed in treatments with these fungi, comparing with the native AMF. Growth of sweet passion fruit seedlings can be improved by mycorrhization with selected AMF, with reduction of time spent on seedling production.