the decayed resistance of three kinds of birches sapwood to white fungi and brown fungi was studied in laboratory with four kinds of preservatives of BBF, CCB, CCA and CCF.
STUDIES ON ACTIVE ANTIFUNGAL SUBSTRATES IN NATURAL DURABLE SPECIES Ⅲ. EXTRACTION, SEPARATION, PURIFICATION AND TOXICITY EXPERIMENT OF EFFECTIVE ANTI-FUNGAL OF HEARTWOOD OF CATALPA BUNGEI
The antidecay of natural bamboos (Phyllostachys pubescens) is worse than natural wood When having the 20% weight lossing rate, the bamboos have lost their worth of utilization.
Some physical and mechanical properties together with the natural decay resistance of the lesser known and lesser utilized timbers of Diospyros mespiliformis, Tyrachylobium verrucosum and Newtonia paucijuga, species from Tanzania were determined.
Natural decay resistance was determined using the brown-rot fungi (Coniophora puteana and Goeophyllum trabeum) and the white rot fungus (Coriolus versicolor) for both heartwood and sapwood in accordance with EN 113 (1993).
Natural decay resistance of Popu lus delioidcs Bartr. Var delloides cv. 'Lux' is determined by soil-bloek method. The test results show that weight loss percentage of this species of wood attached by Coriolus versi color and Gloeop-hllum trabeum arc 51.72% and 71.55% after 9 weeks, respectively, belonging to "non-resistant" species. By observing the hyphal distribution and the penetration in wood cells and microstructural changes of cell walls, the process of degradation of wood cell walls are revealed.
Natural decay resistance of the heartwood of Cunninghamia lanceolata, Phoebe sheareri, Sassafras tzumu, Quercus fabri, and Catalpa bungei was determined by the soil-block method with Coriolus versicolor (white rotter) and Gloeophyllum trabeurn (brown rotter) in the laboratory. The changes in amounts of major components during decay of samples were analysed. The results showed that decay resistance of the heartwoods was very resistant or resistant to both C. versicolor and G. trabeum, but Populus deltoides a...
The changes in ultrastructure and crystallinity of the heartwood of Cun-ninghamia lanceolaia, Catalpa bungei and the sapwood of Populus deltoides during decay by C. versicolor and G. trabtum were studied by Scanning Electron Microscopy and X-ray diffraction method. Results show that Populus dehoidcs was havily rotted by the white-rot and brown-rot fungi. The crystallinity was decreased by 50% after 12 weeks decay by the brown-rot fungus. But treated wity the same methods and duration only slight change were...