ABSTRACT
Symbiotic associations between tree species and mycorrhizal fungi may lead to better growth and nutrition of seedlings and so it becomes an important alternative to the establishment in the field, mainly in edaphic restriction areas, or to species of high nutritional demands. The cultivation of Tectona grandis (teca) in Brazil has been conducted in Cerrado areas with low fertility soils. The aim of the present study is to assess the effect of arbuscular mycorrhizal fungi (AMF) inoculation on the growth and mineral nutrition of teca seedlings. The experiment was performed in randomized blocks (six blocks), with four repetitions: 1) witness (inoculation-free mycorrhizal fungi); 2) inoculation with Rhizophagus clarus; 3) native AMF inoculum from twenty-year old teca cultivation in Mato Grosso state (MT inoculum); and 4) native AMF inoculum from clay extraction in Campos do Goytacazes (Campos inoculum). The plantlets were inoculated and cultivated in 6 dm³ pots for 135 days and assessed for stem hight and diameter of the stem base. Root samples were collected in order to assess the percentage of AMF colonization. The roots and the aerial part were dried, separately, in a forced air circulation oven at 65°C for 72 hours. Subsequently, the dry weight and the content of P, K AND S were determined. The mycorrhizal fungi inoculation, mainly the Rhizophagus clarus isolate and the Campos inoculum, has promoted better growth and K and S acquisition by teca seedlings. The inoculation using mycorrhizal fungi allowed greater nutrient use efficiency.
Keywords:
Teca; mycorrhizae; seedling production