A greenhouse experiment with an alleatory factorial 9 x 4 scheme was carried out to evaluate the effects of different substrates and species of arbuscular mycorrhizal fungi (AMF) on the development of coffee plants, cultivar Catuaí Amarelo, IAC 62. Nine substrates were used: seven commercial organic substrates - four substrates containing composted pinus peel (Rendmax, fertilized Vida Verde, non- fertilized Vida Verde and Terra do Paraíso), three containing coconut fiber (Golden Mix-11, Golden Mix- 47 and Golden Mix 80) and two using soil - a mixture of 70% soil and 30% cattle manure, usually used by the producer, and soil alone. The AMF were Glomus intraradices, Glomus etunicatum and Gigaspora margarita, and a control without AMF inoculation. The plants were harvested 200 days after transplanting and the following variables were analyzed - height, number of leaves, stem diameter, shoot dry weight, root fresh weight, shoot P content, mycorrhizal colonization, total extraradical mycelium, acid phosphatase activity and photosynthetic pigments. Better plant growth conditions were obtained in the substrate Vida Verde without fertilization, regardless of mycorrhiza. Plants colonized by G. margarita and cultivated in the conventional substrate (soil + manure) and Vida Verde with fertilization showed higher P amounts and index of P utilization efficiency, which reverted in better growth and biomass production, resulting in higher symbiotic efficiency. Mycorrhizal plants, cultivated in soil + manure, showed higher chlorophyll values and lower acid phosphatase activity in coffee leaves.
coffee; Coffea arabica; mycorrhiza; substrate; acid phosphatase; photosynthetic pigments
