Resistência natural da madeira de Corymbia maculata (Hook.) K.D.Hill & L.A.S. Johnson a fungos e cupins xilófagos, em condi??es de laboratório

摘要

This research evaluated the natural resistance of Corymbia maculata wood to wood-destroying fungi and termites, under laboratory tests. Radial pieces (boards), containing intact heartwood and sapwood were transformed into test samples measuring 2.00 x 2.00 x 1.00 cm, with the smallest measure in tangential direction (fungi assay) and measuring 2.45 x 2.00 x 0.64 cm; with the largerst measure fiberwise (termite assay), in four positions from pith to bark. The samples were submitted to fungi Postia placenta, Neolentinus lepideus and Polyporus fumosus action for 12 weeks or to Nasutitermes sp. action for 30 days. Wood decay resistance was found to be dependent on the position pith to bark and on the fungus. The wood samples in the most external positions were more deteriorated. Inside of each position, the fungi caused similar deterioration, except for the most external position (sapwood) where the P. fumosus caused less deterioration than other tested fungi. In general, C. maculata wood was highly resistant (internal positions) or resistant (external positions) to the fungi. Just for the Neolentinus lepideus, the external position was classified as moderately resistante. The tested wood to termite resistance was not affected by position in the pith to bark direction and showed weight loss for allanalyzed positions. Besides, it was affected only superficially and the termites died during the assay. The C.maculata wood was classified as resistant to the termites assayed.