Effects of mycorrhizal inoculation on soursop seedlings in fumigated and not fumigated soil

An experimental trial was carried out under greenhouse conditions to evaluate the effects of arbuscular mycorrhizal fungi (AMF) on Annona muricata L. (soursop) seedlings, in a fumigated and not fumigated Yellow Alic Latosol. Mycorrhizal inoculation was done during the transplanting of seedlings. Plant growth and nutrient concentration and content were evaluated five months later. Inoculation increased significantly the growth of soursop in fumigated soil and the increment was greatest in the treatments of Scutellospora heterogama and Gigospora margarita. The inoculation efficiency in fumigated soil varied from 594% to 1,348%. Although the effect of inoculation was much lower in not fumigated soil, treatments with G. margarita, Entrophospora colombiana and Gigaspora sp, still increased significantly plant growth. A 61% inoculation efficiency was obtained with G: margarita while. S. heterogama was not efficient for soursop. In fumigated soil G. margarita and Gigaspora sp. caused the highest percentage of root colonization whereas in not fumigated soil, no significant differences were observed among inoculation treatments. Concentration and content of nutrients varied among treatments. Soursop is a mycorrhizal dependent plant and the inoculation of the specie G: margarita increases the growth of soursop seedlings in fumigated and not fumigated soil.