Morfologia do fuste e propriedades da madeira de Tectona grandis L.f. de plantações em idade de corte final

Abstract

Wood quality can be affected by soil and climate factors, silvicultural management, genetic material and growth rate, making it a concern for the implementation of stands, especially for Tectona grandis plantations, which have a final cut after 20 years. Therefore, the objective was to carry out the morphological, physical and mechanical characterization of 22–23-year-old wood, evaluating the influence of three locations on the quality of the wood, as well as evaluating how the location affects the radial and longitudinal variation in the width of the rings. growth rate and apparent density of the average wood per ring. Trees aged 22-23 years were collected from seminal plantations in the municipalities of Alta Floresta, Nova Maringá and Santo Antônio de Leverger, Mato Grosso, Brazil. For the analysis of morphological parameters, physical properties and X-ray densitometry, discs were used at fixed heights of 2.3 m, up to 11.5 m, representing the beginning and end of five commercial logs. In addition, test specimens were made from rafters from the heart of the first log, to analyze the mechanical properties. The thickness and proportion of sapwood varies along the stem, being greater at higher heights. There is a decrease in the values of total diameter, diameter and proportion of heartwood along the shaft, being greater at the base. The total diameter was influenced by the locations, with the trees in Nova Maringá having the highest values at a height of 11.5 m. The conicity of the log was influenced by the locations and longitudinal variation, being greater at the base and in Alta Floresta. Basic density was not affected by location, with an average of 0.546 g.cm-3 and higher values at the base and top. The apparent density showed a similar pattern along the stem, but the locations had an influence, with a higher average (0.660 g.cm-3 ) for trees from Alta Floresta. There was no influence of the locations on the mechanical properties. The trees showed wider growth rings up to the 5th ring from the pith, with decreases and fluctuations in width along the rays. The apparent density pattern is similar for the three locations, with higher values at the base and thinner end, and lower values near the pith, tending to increase near the bark. It is concluded that the morphological and physical properties vary along the stem, the location influences the total diameter, the apparent density, dimensional stability, the width and apparent density of the growth rings, but does not affect the mechanical properties, and the wood 22-23 year old teak presents satisfactory quality for obtaining sawn products.