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Mould growth at lumber surfaces of pine after kiln and air drying
1994 - IRG/WP 94-40033
Distribution of water soluble substances in green wood and later redistribution during drying is of importance for the colonisation of wood by microorganisms. According to literature the availability of nitrogenous materials is probably a major limiting factor to the microbial colonisation of wood. King et al. (1974) and Oxley et al. (1976) have shown correlation between surface nutrient concentration and the degree of invasion by soft rot fungi. Although the effects of some factors on the susceptibility of wood to mould have been studied (Land 1986, Hallenberg and Gilert 1987, Bjurman 1989a, b), the effect of the drying treatment was not considered. In the study by Theander et al. (1993) it has been indicated that the growth of the mould fungi Penicillium brevicompactum and Aspergillus versicolor is positively correlated with the content of nitrogen and low-molecular carbohydrates. Kiln and air drying cause redistribution of the soluble sugars and nitrogen in different ways and the effect of kiln drying varies depending on the drying schedule (Terziev et al. 1993, Terziev 1994). The major goal of the present study was to investigate whether different drying treatments of wood (causing different redistribution of low-molecular sugars and nitrogen) create different susceptibility for mould growth. The material for the moulding tests was from the above mentioned studies of Terziev et al. (1993) and Terziev (1994). Thus, drying history and contents of soluble sugars and nitrogen were known for the test material. No data were found in the literature about mould growth after different drying treatments. The present experiment is to be considered as a preliminary study.
N Terziev, J Bjurman, J B Boutelje

Preliminary study of the fungicidal and structural variability in copper naphthenates and naphthenic acids
1996 - IRG/WP 96-30114
Copper naphthenates, an oil-borne wood preservative listed by the American Wood-Preservers' Association (AWPA), is manufactured by complexing copper(II) with naphthenic acids. Prior to AWPA listing as a wood preservative, field experiments showed that copper naphthenates generally had good stability and were active against wood-destroying organisms. Recently, however, there have been reports of some copper naphthenate-treated poles rapidly failing. One possible explanation for the varying effectiveness could be that the structure, and resulting biological activity, of the naphthenic acids used to make copper naphthenate may vary. To test this hypothesis several naphthenic acids and copper naphenates were obtained and their fungicidal activity against three wood-destroying fungi measured. In addition, the chemical structure of the naphthenic acids were examined by proton- and carbon- NMR. Different activities were observed, especially against a copper-tolerant fungus. Some apparent correlations were seen between the fungicidal activity and chemical structures for the few samples studied.
T Schultz, D D Nicholas, L L Ingram Jr, T H Fisher

Sequestration of copper ions by the extracellular mucilaginous material (ECMM) of two wood rotting basidiomycetes
2004 - IRG/WP 04-10533
The radial growth rate of colonies originating from either whole or ECMM-free inocula of Coriolus versicolor was investigated. The presence of ECMM allowed colonies to maintain higher growth rates than those form ECMM-free inocula up to 2 mM CuSO4 in the medium. The ECMM of C. versicolor and G. trabeum was able to reduce the diffusion of copper ions in solution. The ‘raw’ ECMM of both fungi had a greater ability to reduce the diffusion of copper ions than ECMM which had been subject to dialysis to remove soluble, low molecular weight components. The ‘insoluble’ fraction of ECMM for both species was more effective than the ‘soluble’ fraction at reducing the diffusion of copper ions. It is concluded that ECMM confers some protection to hyphae against the toxic effects of copper ions on growth in vivo and that this due to the binding of copper ions to both the polysaccharide and to low molecular weight components of the ECMM
D Vesentini, D J Dickinson, R J Murphy

The decay resistance of chemically modified aspen composites to the white rot fungus Coriolus versicolor (L.) Quelet
1998 - IRG/WP 98-40122
Chemical modification of Aspen wood (Populus tremula L.) in the form of solid wood, veneers and sawdust was undertaken by a two step procedure consisting of esterification with maleic anhydride (MA) and subsequent oligoesterification with MA and glycidyl methacrylate (GMA) or allyl glycidyl ether (AGE). Modified wood was thermoplastic and was thermally formed by hot-pressing to produce veneer or solid wood samples with smooth glossy surfaces, while plastic-like wafers were obtained by hotpressing modified sawdust. Chemical modification alone was shown to enhance the biological resistance of Aspen to decay by Coriolus versicolor. In addition, hot-pressing enhanced decay resistance of both unmodified wood and esterified wood veneer samples, although no improvement was found by hot pressing oligoesterified wood. The most effective treatment for the improvement of decay resistance was chemical modification of the sawdust in conjunction with hot-pressing. A microscopic examination of chemically modified and control samples following exposure to the fungus showed more extensive colonisation and decay in untreated, unpressed samples.
M C Timar, A J Pitman, M D Mihai

Fungicidal activity of some organic solvents, copper carboxylates and their complexes with 2-aminoethanol
1997 - IRG/WP 97-30136
We evaluated the activity of eight organic solvents against wood - rotting fungus Trametes versicolor in order to choose the most appropriate one for rapid screening tests of some copper(II) carboxylates and their adducts with 2-aminoethanol. Their activity against the selected fungus was classified in the following order: chloroform > N,N-dimethylformamide > acetonitrile > methanol > dimethyl sulfoxide > ethanol > acetone. The non-polar white spirit did not dissolve in the growth medium and the results could not be directly compared with the results for other solvents. As an appropriate solvent for screening of the tested copper(II) carboxylates, dimethyl sulfoxide (DMSO) was chosen. Minimal inhibitory concentration against Trametes versicolor of the screened carboxylates was in the concentration range of 1x10-4 to 1x10-3 mol/l. Coordinated amine ligands slightly, and not significantly, decreased fungicidal properties of the tested carboxylates.
M Petric, F Pohleven

CCA modifications and their effect on soft rot in hardwoods
1982 - IRG/WP 3201
Decay tests were carried out on wood samples treated with three waterborne compounds all identical in composition but applied in different forms. There were significant differences in the effectiveness of the treatments particularly as regards the control of soft rot.
S M Gray, D J Dickinson

Contribution to the testing of wood based board material
1982 - IRG/WP 2176
R G Lea

Fungicidal and termiticidal effectiveness of alkylammonium compounds
1983 - IRG/WP 3232
This paper is related to effectiveness of several AAC's against wood decay fungi and termites by Japanese standardized test methods.
K Tsunoda, K Nishimoto

Interspecific variability of European oak durability against white rot fungi (Coriolus versicolor): Comparison between sessile oak and peduncle oak (Quercus petraea and Quercus robur)
2001 - IRG/WP 01-10393
The knowledge of wood natural durability against biologic predators enable its external use. The resistance of European oak wood was reported like durable according to the EN 350-2. However, some individuals may contain high durable wood. Our research was focused to understand this variability in oak population that represent the first french species (4.1 millions of ha). Natural durability of European oak heartwood (Quercus petraea and Quercus robur) against white rot fungi (Coriolus versicolor) was tested according to european standard EN 113. The experimental material consists in 23 oaks robur and 26 petraea oaks sampled from 9 French regions. For each tree, 3 twin samples were taken off from heartwood situated at 1.30 m from the bottom of the tree. Different effects were tested by hierarchic variance analysis: "species", "forest within species" and "tree within forest". The tree effect is very significant for biologic natural resistance. Variability between species was also demonstrated. Although the species effect is significant, it's relatively weak compared with tree differences (it was declared significant 5%). Durability classification was determined according European standard EN 350-1. 69.2% of petraea oak trees are classified as high durable, 19.2% durable, 7.7% moderately durable and 3.8% slightly durable. In the case of robur oak 91.3% of trees are classified as high durable and 8.7% durable.
N Ayadi, B Charrier, M Irmouli, J P Charpentier, C J Allemand, F Feuillat, R Keller

Successive collections of Basidiospores from wood decay fungi (in vitro) show variation in germination levels on common media
1978 - IRG/WP 191
In the course of various preliminary experiments in which spore germination levels of 6 decay fungi on malt and water agar were recorded as controls, it was noted that one could not reliably obtain an expected level of spore germination for any particular fungus. Inconsistent 'control' spore germination levels of a fungus greatly complicates large scale experiments in which comparisons of data based on germination levels are attempted upon replication of the study over time. This study was done to determine if, in fact, spores collected at different times from specific hymenial areas of wood decay fungi sporulating in vitro differed significantly in germination level on common media under standardized conditions.
E L Schmidt, D W French

The biostatic effect of copper on decay of fire retardant-treated mining timber
1991 - IRG/WP 1507
Blocks of Eucalyptus grandis were treated with 20kg/m³ ammonium sulphate as fire retardant and challenged with Coriolus versicolor. Replicates were soil buried. A second set of blocks was treated with retardant and copper at 6.6 kg/m³ (ie 1% w/w), and challenged similarly. After 8 weeks weight losses produced by Coriolus versicolor in untreated, retardant treated and copper supplemented blocks were 45, 25, and 0% respectively, and corresponding weight losses in soil were 27, 25 and 10%. These results, and electronmicroscopical observations, showed conclusively that Eucalyptus grandis treated with fire retardant was rapidly decayed, and that copper inhibited such decay.
G D Shelver, E A Shelver, A A W Baecker

Chemical compounds from Eperua falcata and Eperua grandiflora heartwood and their biological activities against wood destroying fungus (Coriolus versicolor)
2005 - IRG/WP 05-30373
The chemistry analysis of the compounds present in dichloromethane and ethanolic fraction as well as bioassays enables to understand the durability differences of Eperua falcata and Eperua grandiflora. The principal distinction between these two species is the acidic subfraction of diterpenoic extract, which is antifungic in Eperua falcata when tested in in-vitro conditions. This study also enables to show that ethanolic fraction plays an important role in the mechanism of natural durability. It also reports the first isolation of cativic acid in Eperua falcata wood.
N Amusant, C Moretti, B Richard, E Prost, J M Nuzillard, M-F Thévenon

Decay in external joinery in the United Kingdom
1978 - IRG/WP 3116
no abstract available
J G Savory, J K Carey

Virulence testing of cultures of different origins of the test fungus Coriolus versicolor strain CTB 863 A
1986 - IRG/WP 2267
The virulence of cultures of different origins of Coriolus versicolor CTB 863 A - a strain which is mentioned in EN 113 - was tested. Standard blocks of beech wood were used at temperatures of 20-22°C and 26-28°C and particleboard was tested at 26-28°C. The decay capacity of the different inoculations varied widely, as could be expected it was greatest at the higher temperature level.
W Kerner

Report on the monographic card on Coriolus versicolor
1972 - IRG/WP 111
C Jacquiot

About the relations between the natural durability of some tropical species and their extractives content
1983 - IRG/WP 1208
G R Y Déon

Rapport sur la fiche monographique concernant le Coriolus versicolor
1972 - IRG/WP 109
C Jacquiot

The evaluation of synergistic effects of chemicals on fungicidal efficacy in crossed-paper tests
1991 - IRG/WP 2383
The mixing effects of wood preservatives were evaluated using the crossed-paper technique. Two filter paper strips (0.7 x 8 cm²) were treated by soaking with different chemicals [fungicides, a termiticide (chlorpyrifos or phoxim), a surface-active agent, a synergistic agent, and a stabilizer], and placed at right angles to each other on a fully grown mycelial mat of a test fungus in a Petri dish. When the four organoiodine fungicides were incorporated with chlorpyrifos or surface active agent, only 3-iodo-2-propynyl butyl carbamate (IPBC) showed the desirable synergistic effect against every wood-decaying fungus tested. Other fungicides did not always tend to produce the synergistic effect with the addition of a surface active agent. 4-Chlorophenyl-3-iodopropargyl formal (IF-1000) appeared to indicate an undesirable antagonistic effect when mixed with either chlorpyrifos or a surface active agent. 3-Bromo-2, 3 diiodo-2-propenylethyl carbamate (EBIP) did not show any synergistic action by mixing with chlorpyrifos and/or a surface active agent, although the fungicidal enhancement was induced satisfactorily by mixing the fungicide with chlorpyrifos, a stabilizer and/or a synergistic agent, especially against Tyromyces palustris and Coriolus versicolor. Similarity of the results obtained in the present investigation and in the previous laboratory decay tests leads to the conclusion that the crossed-paper technique is suitable for the evaluation of the mixing effect of chemicals on fungicidal efficacy.
Dong-heub Lee, K Tsunoda, M Takahashi

Basidiosporogenesis by the white-rot basidiomycetes in vitr
1994 - IRG/WP 94-10081
Basidiospores of all forest-inhabiting basidiomycetes are a primary source of infection causing wood decay. However, most studies evaluating wood preservatives have used mycelia or basidiospores obtained from wild mushrooms. The objective of this study was to demonstrate in vitro methods that promote carpogenesis and basidiosporogenesis by the white-rot basidiomycetes, Schizophyllum commune and Trametes versicolor. After preincubation in the dark at 27°C for three to fifteen days, basidiospores were produced in four to sixteen weeks in basidiomes exposed to light at 12°C. Adequate light exposure, aeration, and low temperature treatment after preincubation are essential for fruiting body of these white-rotting basidiomycetes. Carpogenesis and basidiosporogenesis of Schizophyllum commune is controlled by nitrogen and carbon limitation. However, fruiting body formation in Trametes versicolor was induced by nitrogen limitation. Walset cellulose was found to be the best carboun source for carpogenesis and subsequent basidiosporogenesis. These results demonstrate the feasibility of using various potential inhibitors on basidiospore germination rather than relying on mycelial growth.
S C Croan

The effect of treatment method on CCA efficacy in Corsican pine
1992 - IRG/WP 92-3723
As part of a study into the influence of application method on preservative efficacy Corsican pine (Pinus nigra) samples (50 x 50 x 400 mm³) were treated with a CCA formulation using Bethel, Steam/Bethel or Lowry processes. Full penetration of the preservative at a gross level was confirmed using a copper disclosing reagent. The preservative was allowed to fix and then samples were converted into mini-blocks (30 x 10 x 5 mm³) to produce decay test samples from various locations within the larger samples. After leaching, sets of replicate mini-blocks were exposed to the decay fungi Coniophora puteana FPRL 11E, Coriolus versicolor FPRL 28A, and Chaetomium globosum FPRL S70K. Equivalent sets of leached blocks, were analysed using atomic absorption spectrophotometry to determine preservative concentration and balance. The results of this study have been used to assess the effect of preservative application method on CCA efficacy. They also indicate how treatment method affects the distribution of the active elements of the preservative throughout the treated wood.
P R Newman, R J Murphy

Use of biossay to determine CCF and CCB preservative retentions in treated Pinus sylvestris
1984 - IRG/WP 2216
The retention of each a copper/chromium/boron and copper/chromium/fluoride preservative in pressure treated pinepoles was tested by bioassay using Aspergillus niger as test fungus. Small samples of 5 mm³ were taken from various depth of the poles and placed on potato-dextrose agar plates. The inhibition of fungal growth depends on the preservative retention in the cubes and corresponds closely to results obtained by atomic absorption spectrophotometry.
J C Moreschi, H Willeitner

Some wood-destroying Basidiomycetes. Volume 1 of a collection of monographs
1981 - IRG/WP 1121
One of the first tasks of the International Research Group on Wood Preservation, when it began its work in 1969, was to compile a series of reports on the common decay fungi which can attack wood. This volume, which contains the first of these reports, has been compiled with the help of mycologists and wood preservation specialists in France, Ghana, the Federal Republic of Germany, the Netherlands, Poland, Sweden and Switzerland, and the United Kingdom. It gives up-to-date information on fifteen common Basidiomycete fungi and indicates the gaps in the world's present knowledge that exist about these.
R Cockcroft

Synergistic effects between 2-HPNO, Irganox 1076 and EDTA on the inhibition of wood degradation by Coriolus versicolor
2004 - IRG/WP 04-30331
The efficiency of 2-hydroxypyridine-N-oxide (2-HPNO) as wood preservative has been investigated. As shown using classical experiments as well as using response surface methodology, the efficiency of 2-HPNO as wood preservative is strongly improved in presence a chelator like EDTA and/or of Irganox 1076 an industrial antioxidant. In these conditions, wood preservative efficiency of the mixture the three previous compounds is quite similar to that of tebuconazole used alone. 2-HPNO exhibits an hydroxamic acid function and is a susbtrate of fungal peroxidase. These properties could explain the observed synergy. The implications of these data for the design of new wood preservation strategies are also discussed.
A Mabicka, S Dumarçay, N Rouhier, M Linder, J P Jacquot, P Gérardin, E Gelhaye

The leachability, biological resistance, and mechanical properties of wood (Pinus sylvestris L.) treated with CCA and CCB preservatives
1999 - IRG/WP 99-30207
Scots pine (Pinus sylvestris L.) specimens treated with CCA and CCB preservative solutions (1.0%) were subjected to several fixation processes and leached elements from the specimens were determined. In addition, the specimens exposed to different fixation temperatures were subjected to soil-block test using two brown-rot fungi and one white-rot fungus in order to investigate the effects of fixation temperature on the biological performance of treated wood. The effects of preservative treatment and subsequent redrying at temperatures of 20°C and 70°C on the bending strength, MOE (modulus of elasticity), and impact bending strength of small, clear specimens treated with CCA. At 20°C and high moisture contents and also with steaming, leaching rate of the components decreased. In addition, the specimens treated with CCB and conditioned at 20°C/32-100% RH (relative humidity) conditions, the percent elements leached were less than those in the specimens treated with CCA and also the rate of fixation increased significantly in the CCB-treated specimens. In the CCA treatments, the weight losses by Gloeophyllum trabeum and Postia placenta fungi were more than 5% with the fixation methods such as ovendrying at 120°C, and steaming at 80°C for 60 and 90 minutes while with the other fixation methods, the weight losses obtained were less than 5%. At redrying temperatures of 20 and 70°C, CCA had no significant negative effect on the bending strength, MOE, and impact bending strength properties of the specimens.
S N Kartal

Mold inhibition on unseasoned southern pine
2003 - IRG/WP 03-10465
Concerns about indoor air quality due to mold growth have increased dramatically in the United States. In the absence of moisture management, fungicides need to be developed for indoor use to control mold establishment. An ideal fungicide for prevention of indoor mold growth on wood-based materials needs to specifically prevent spore germination and provide long-term protection under conditions of high humidity. Fungicides intended for indoor use must exhibit no mammalian toxicity, be odorless and emit no VOCs. Classes of compounds meeting one or more of these criteria include acids, phenolic compounds (antioxidants), pharmaceuticals, commercial and experimental wood preservatives, food preservatives, and plant essential oils. Wood preservatives and food preservatives were initially screened at various concentrations for inhibitory properties to mold fungi on 2% malt agar (MA). Many compounds that inhibited the test fungi on MA failed to substantially inhibit mold growth on unseasoned southern pine at higher concentrations than the minimal inhibitory concentration determined on MA. Subsequently, compounds were screened on unseasoned southern pine stakes. Pine stakes were dipped for 15 seconds in varying concentrations of the test chemicals according to the ASTM standard test method D4445 for controlling mold on unseasoned lumber. Stakes were challenged with Penicillium chrysogenum PH02, Aspergillus niger 2.242, and Trichoderma viride ATCC 20476 spore preparations. Following a 4-wk incubation, stakes were rated from 0-5 with 5 representing heavy mold growth. An inihibition rating of 0 to 1 is indicative of successful mold inhibition. The best overall average ratings for wood preservatives were seen in stakes treated with 5% Bor-A-plus or Cu+, which were highly inhibitory to all test fungi. High concentrations of ethanolamine (10%) and thujaplicin (10%) were inhibitory to all test fungi. Pine resin (50%) solely inhibited P. chrysogenum. Of the food preservatives tested, five percent sodium benzoate and potassium sorbate inhibited all test fungi, while calcium propionate selectively inhibited A. niger. Pharmaceutical antifungals such as voriconazole (2.5mg/mL), thiabendazole (25mg/mL), and miconazole (20mg/mL) completely inhibited all test fungi on unseasoned pine, while other azole-derivatives failed to inhibit mold growth. Nystatin (10,000 units/mL) inhibited only A. niger. A combination of effective chemicals should be considered as one strategy to provide long-term protection of wood-based building materials from mold establishment.
C A Clausen, V W Yang

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