Efeito da aplicação do extrato de cuia (crescentia cujete l.) Na resistência natural e estabilidade dimensional da madeira de marupá (simarouba amara aubl)

Abstract

The present study aimed to evaluate the effect of the application of cuia extract (Crescentia cujete L.) on the physical properties and natural resistance of marupá wood (Simarouba amara L.) submitted to accelerated decay test in laboratory with the fungi Gloeophyllum trabeum, which causes brown rot; and, Irpex lacteus, which causes white rot. Fungal inhibition tests were performed in a Petri dish containing malt:agar culture medium, in which 300 μL of the extracts were added in different prepared dilutions (0, 1, 2, 4 and 8% w/v). Then, the extracts were impregnated by immersion in the marupá wood, with the aid of a vacuum pump and the retention of the impregnated product was determined. For the natural resistance assay, wood samples impregnated with Crescentia cujete extracts were used, later subjected to the action of brown rot fungi and white rot fungi for 12 weeks, after this period, the samples were dried in an oven and then the percentages of mass loss were calculated and classified according to the degree of natural resistance. The mean results were compared by Tukey's test at 5% significance. The analysis of variance did not indicate significant difference for the different concentrations of wood impregnated and submitted to the fungi G. trabeum and I. lacteus. For the results of shrinkage in the respective tangential, radial directions, it is observed that the values were similar between the concentrations tested, not indicating the effect of the tested extract on the dimensional stability of the Simarouba amara wood.