Growth and nutrient contents of avocado, mango and papaya seedlings under the influence of different vesicular-arbuscular mycorrhiza fungal species.
Silva L. F. C., Siqueira J. O.
Author Affiliation: Florestas Rio Doce S/A., CEP 65906 Açailândia, MA, Brazil.
Revista Brasileira de Ciencia do Solo 15 : 283-288
Abstract : The effect of 6 VAM fungi, inoculated singly or in combination, on initial growth and nutrient contents of avocado, mango and pawpaw seedlings was studied under greenhouse conditions in a soil-vermiculite mix amended or unamended with soluble superphosphate (SS). All fungal species established on roots of all the plant species studied. However, root colonization and plant growth effects differed among inoculated fungi. In soil mix amended with SS, growth of avocado seedling was enhanced by Glomus clarum, G. intraradix [G. intraradices], Scutellospora heterogama and Gigaspora margarita. When soil mix was not amended with SS, only S. heterogama enhanced plant growth. Mango seedlings had a better growth response only when inoculated with G. margarita and mixed inoculum in SS-amended soil. Growth of pawpaw seedlings was significantly improved by most fungal species in unamended soil mix. However, when SS was added, only G. clarum promoted growth. Mycorrhizal inoculation effects were around 85% for pawpaw in unamended substrate. It dropped to half when SS was incorporated into soil mix. Mycorrhizal effects were 30 and 20% for mango and avocado, respectively, in soil with SS and non-significant in unamended soil-mix. Growth responses were related to the contents of P, Zn and S. It is concluded that combined use of superphosphate and inoculation with selected VAM fungi is advantageous to early growth of these plants.