Plasticidade fenotípica e frações fosfatadas em espécies florestais como resposta à aplicação de fósforo

Abstract

The experiment under greenhouse conditions was carried out at the Federal University of Minas Gerais, Brazil, aiming to evaluate the initial growth, efficiency of use of P and phosphorus content in three forest species submitted to four levels of P. The experimental design was completely randomized in a factorial arrangement 3 × 4, with three replicates. Seedlings of Astronium fraxinifolium Schott and Stryphnodendron Adstringens (Mart.) Coville, Cerrado native species, and Acacia mangium Willd., an exotic specie, were cultivated on a Red- Yellow Latosol treated with four phosphorous levels (0, 150, 300 e 600 mg dm −3). After 240 days from the plants emergence the following variables were determined: height, root collar diameter, dry weight production, total phosphorous soluble in acid and P fractions. Different phosphorus doses influenced the initial growth, absorption, total content and content of P fractions in the three studied species. Acacia mangium presented higher growth in the higher doses of phosphorus, in relation to the native species. The Cerrado species had higher enhancement of root and P storage ability in inorganic forms, standing out Stryphnodendron adstringens. The relation inorganic P:organic P was considered as suitable for the P nutritional status evaluation of forest species.