Résumé
The availability of water and fertilizer in forest stands promotes changes in cambial activity of trees, causing significant changes in wood anatomical features and wood formation. The study aimed to evaluate the wood anatomical characteristics of Eucalyptus grandis trees at 24 and 36 months with reduced rainfall and nutrition of K and Na. Treatments were defined by two water regimes (100% and 66% of rainfall, artificial reduction with polyethylene tarps) and three types of nutrition: K (4,5 kmol/ha), Na (4,5 kmol/ha) and control. 3 eucalyptus trees were selected per treatment and age, totaling 36 sampled trees, and discs samples of wood at 1.3 m height (DBH) were evaluated in relation to anatomical characteristics. The results showed that treatments nutrition x water availability induced changes in width, wall thickness and lumen diameter of the fiber at 24 months and did not alter the vessel dimensions in wood of E. grandis trees. The effect of isolated application of K and Na does not influence the wood anatomical characteristics of E. grandis, except for width, lumen diameter and wall thickness at 24 months. The reduction of the rainfall, with installation of polyethylene tarp, does not significantly influence the dimension of the fibers and the vessels of wood in the eucalyptus trees. The results may be used as subsidies for the adoption of silvicultural practices in forest plantations in areas with water stress, as well as the partial replacement of K by Na.