Potencialidade de óleos essenciais como preservantes naturais de madeira contra a ação de fungo da podridão branca

Abstract

The present study aimed to evaluate the potential fungitoxic of essential oils of Pinus elliottii and Melaleuca alternifolia as natural preservative of wood, as well as your toxicity to rot fungus Trametes versicolor. For this, this work was divided into two main stages: the first was the fungitoxic testing to verify the potential of essential oils and find the best concentration. These were employed through essays in culture medium, also known as fungitoxic tests, and evaluated through the index of mycelial growth. After we found the fungitoxic potential of the oils, the second stage was held through rotting essay, we made specimens of wood of Pinus sp. and they were treated with concentrations of oil of Pinus elliottii, used in accordance with the results found in the previous step, the biodeterioration of the exposed material was evaluated basis on the loss of mass, chemical analysis and hardness testing.The results indicated that the essential oil of Pinus elliottii is toxic to the fungus development, showing that the higher product concentration in the culture medium, the greater was its fungitoxic potential, inhibiting mycelial growth of the fungus. In the essential oil of Melaleuca alternifolia, even showing some degree of toxicity, this did not completely inhibit the development of fungus. For the effect on wood preservative in relation to mass loss test we used two concentrations of the essential oil of Pinus elliottii, 0.050 0.075%, and its performance were compared with the control treatments: uppermost treatment, without treatment and without contact with the fungus and lowest treatment, without treatment and in contact with the fungus, in other words, check the natural resistance. The loss in mass showed significant difference of the treatments with essential oil that had lower loss in mass than control treatments. On the chemical components evaluation, not only lignin but also the polyoses were affected by decomposition, being proved through the results that the treatment performed with Pine essential oil with 0.075% did not differ statistically from the uppermost treatment control. The Janka hardness presented results that prove the efficiency of essential oil as natural wood preservative, showing similar performance when compared to the uppermost treatment control.