Efficiency of extracts from Amazonian species in protecting the wood of Hevea brasiliensis Muell. Arg. against xylophagous fungi

Abstract The research aimed to evaluate the effect of transferring extracts from residues of durable Amazonian wood species processing to a non-durable wood species (rubber tree) to prolong its use. For this purpose, three trees of rubber tree (27 years old) were collected from Santa Maria farm in the district of Pacotuba, Cachoeiro de Itapemirim, south of the state of Espírito Santo, Brazil. These trees were transformed into samples for testing basic density, dimensional stability, retention and pH of the extracts, and resistance of the samples impregnated with the solutions obtained to xylophagous fungi. The impregnation of the wood was carried out using alcoholic extracts (solutions) of Hymenolobium flavum , Roupala montana, Dinizia excelsa , and Tectona grandis . The rubber tree wood had a medium density and moderately stable dimensional stability. The extracts were used in concentrations of 2, 4 and 8 % and tested against brown-rot fungi ( Rhodonia placenta and Neolentinus lepideus ) and white-rot fungi ( Polyporus fumosus and Trametes versicolor ). The extracts exhibited acidic pH (3.5–6.1), which contributed to the effectiveness against the tested fungi. The extracts of R. montana and T. grandis , at concentrations of 4 and 8 %, were more effective in controlling the development of xylophagous fungi.