ARBUSCULAR MYCORRHIZAL FUNGI AND PHOSPHORUS DOSES ON COFFEE GROWTH UNDER A NON-STERILE SOIL¹

FUNGOS MICORRÍZICOS ARBUSCULARES E DOSES DE FÓSFORO NO CRESCIMENTO DO CAFEEIRO EM SOLO NÃO ESTERILIZADO

ABSTRACT

The use of mycorrhiza is a promising biotechnology that makes coffee cultivation sustainable in the use of fertilizers. In this sense, plant growth and phosphorus contents were assessed in coffee inoculated with Rhizophagus clarus, Claroideoglomus etunicatum and Dentiscutata heterogama in soil fertilized with 0, 0.74, 1.48 and 2.96 g P₂O₅ kg^-1. The experimental design was a randomized block design in a 4 × 4 factorial scheme with four replications. The mycorrhizal seedlings were previously produced and later transplanted to pots, simulating the field planting. The assessments were performed 150 days after transplanting. All variables were influenced by inoculation, but the effects were dependent on P doses. P doses higher than 50% of the recommended dose (0.74 g P₂O₅ kg^-1) decreased the benefit of mycorrhiza. The fungi Rhizophagus clarus and Claroideoglomus etunicatum promoted a higher growth of coffee plants when compared to non-inoculated plants in non-sterilized soils and with a reduction in the applied P.

Keywords:
Biotechnology; Coffea arábica L; Phosphate fertilization; Symbiosis