Natural resistance of eight wood species from Caatinga, an exclusive Brazilian biome, was evaluated according to [ASTM Standard (2005) D 2017-05. Standard test method of accelerated laboratory test of natural decay resistance of woods.]. Samples were exposed to white rot (WR) and brown rot (BR) fungi, namely toTrametes versicolor(WR),Pycnoporus sanguineus(WR), Gloeophyllum trabeum(BR) andGloeophyllum striatum(BR). Weight loss, specific gravity and extractive content of each wood species were evaluated.Diptychandra aurantiaca,Pterodon abruptusandTerminalia fagifoliawere classified as “highly resistant”, whileT. fagifoliawas “resistant” toT. versicoloronly.Machaerium acutifoliumwas resistant to all fungi.Aspidosperma multiflorumwas resistant to WR fungi andCombretum glaucocarpumto a BR fungus. The speciesPityrocarpa moniliformisandSwartzia psilonemawere moderately resistant.

This study aimed to assess the natural durability of 20 Amazonian wood species preserved with chromated copper arsenate (CCA) after 30 years in ground contact in an experimental field test at National Forest of Tapajós, Pará state - Brazil. Heartwood samples with a cross-section of 5 × 5 cm and 50 cm of length were half-buried in soil and inspected every year for decay. The species were classified according to natural durability following the classification method proposed by Findlay (Findlay, W.P.K. (1985). The nature and durability of wood. In: Findlay, W.P.K. (Ed.), Preservation of timber in the tropics. Springer Science, Whitchurch, pp. 1–13). After 30 years in ground test, six species were classified as Perishable, seven as Non-durable, three as Durable and four as Very durable, namely: Trichilia lecointei, Lecythis pisonis, Pseudopiptadenia suaveolens, and Dipteryx odorata (Very durable), Protium tenuifolium, Dinizia excelsa, and Ormosia paraensis (Durable), Endopleura uchi, Goupia glabra, Pouteria egregia, Tachigali chrysophylla, Tachigali paraensis, Vatairea sericea, and Vochysia maxima (Non-durable) and Chrysophyllum lucentifolium, Couratari oblongifolia, Didymopanax morototoni, Lueheopsis duckeana, Sterculia excelsa, and Xylopia nitida (Perishable). CCA preservative treatment was effective to promote timber protection, even under harsh climatic conditions of the Amazon forest environment.

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A busca por produtos naturais que possam substituir preservantes da madeira sintéticos é crescente. Dentre estes produtos, estão os óleos essenciais (OEs). Portanto, o objetivo deste estudo foi avaliar a atividade antifúngica dos OEs de Blepharocalyx salicifolius, Nectandra grandiflora, Nectandra megapotamica e Piper gaudichaudianum, sobre os fungos apodrecedores de madeira Trametes versicolor e Gloeophyllum trabeum. Os OEs foram extraídos por hidrodestilação e foram caracterizados quimicamente. A atividade antifúngica dos OEs foi avaliada pelo teste de difusão em placas de Petri. A verificação da inibição foi calculada com auxílio do software ImageJ®. Os componentes majoritários dos OEs de B. salicifolius e P. gaudichaudianum foram eucaliptol e dilapiol, respectivamente. Biciclogermacreno foi o constituinte majoritário do óleo essencial (OE) de folhas de N. megapotamica, enquanto que a deidrofuquinona foi majoritária nos OEs de folhas e frutos de N. grandiflora. A maior inibição do crescimento de T. versicolor foi causada pelo OE de N. megapotamica, com 31,4%. Os maiores percentuais de inibição observados sobre o crescimento de G. trabeum foram proporcionados pelos extrativos de P. gaudichaudianum e B. salicifolius, com 13,9 e 7,5%, respectivamente. Contudo, o resultado deste último não diferiu dos demais OEs avaliados. Os resultados indicaram que o extrativo de espécie de Nectandra que apresentou maior efeito sobre T. versicolor foi N. megapotamica. Entretanto, este gênero não foi tão eficiente contra G. trabeum. Palavras-chave: biciclogermacreno; deidrofuquinona; dilapiol; eucaliptol; Gloeophyllum trabeum; Trametes versicolor.   Blepharocalyx, Nectandra and Piper essential oils: activity on wood-decay fungi   ABSTRACT: The search for natural products that can replace synthetic wood preservatives is growing. Among these products are essential oils (EOs). Therefore, the aim of this study was to evaluate the antifungal activity of EOs from Blepharocalyx salicifolius , Nectandra grandiflora , Nectandra megapotamica  and Piper gaudichaudianum  on the wood-rotting fungi Trametes versicolor and Gloeophyllum trabeum. The EOs were extracted by hydrodistillation and chemically characterized. The antifungal activity of the EOs was evaluated by the Petri dish diffusion test. The inhibition verification was calculated using ImageJ® software. The major components of the EOs of B. salicifolius and P. gaudichaudianum were eucalyptol and dillapiol, respectively. Bicyclogermacrene was the major constituent of N. megapotamica leaves essential oil (EO), while dehydrofuquinone was the major constituent of the EOs from N. grandiflora leaves and fruits. The highest growth inhibition of T. versicolor was caused by N. megapotamica EO, with 31.4%. The highest inhibition percentages of G. trabeum growth were provided by P. gaudichaudianum and B. salicifolius extractives, with 13.9 and 7.5%, respectively. However, the result of the latter did not differ from the other EOs evaluated. The results indicated that, from the extractives of Nectandra species, the greatest effect on T. versicolor was detected to N. megapotamica EO. However, this genus was not so efficient against G. trabeum. Keywords: bicyclogermacrene; dehydrofuquinone; dillapiole; eucalyptol; Gloeophyllum trabeum; Trametes versicolor.

The natural durability of the wood is essential for the definition of its use, and this property can be enhanced with the proper chemical treatment of the wood. Thus, the objective of this study was to evaluate the resistance to termites and decay fungi of Jacaranda copaia wood chemically modified through acetylation. Five experimental treatments were assessed: acetylation for 2, 4, 6 and 8 hours and a control (non-acetylated). The acetylation was carried out by immersing wood samples in acetic anhydride at 90 °C. Acetylated and control samples were subjected to the action of xylophagous termites (Nasutitermes sp.) and decaying fungi (Gloeophyllum trabeum and Trametes versicolor). The acetylation process significantly increased the resistance of Jacaranda copaia wood to the attack of the xylophagous organisms. There was no mass loss after exposure to termites of the wood in any of the acetylation treatments, while in the control wood, mass loss was 9.5%. Regarding the decaying fungi, mass loss occurred in all treatments. Acetylation for 6 and 8 hours were the most efficient chemical treatments, increasing the resistance class of the Jacaranda copaia wood to highly resistant.