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Termite and decay protection - A superficial barrier field test
1983 - IRG/WP 3257
Samples of Pinus radiata were given a superficial barrier treatment and installed in the ground at two sites for five years to observe termite and fungal attack. The three best treatments of the series were Denso petroleum tape, Koppers hot dip tar enamel, and Arquad 2C/75 alkyl ammonium compound. As new fungicides and insecticides become available they are being added to the test using the same system of treatment and exposure.
R S Johnstone, W D Gardner

Effect of a penta emulsion on the service life of Douglas fir, heartwood posts
1978 - IRG/WP 3112
C S Walters

The identification and preservative tolerance of species aggregates of Trichoderma isolated from freshly felled timber
1992 - IRG/WP 92-1553
The surface disfigurement of antisapstain treated timber by preservative-tolerant fungi remains a major problem in stored timber. Identification of a range of isolates of Trichoderma based on microscopic morphological characteristics was found to be imprecise due to the variable nature of this organism. In addition, studies to compare visual (morphological) characteristics of these isolates with their tolerance to the antisapstain compound methylene-bis-thiocyanate (MBT) using minimum inhibition concentration (MIC) tests showed no clear correlations. Isoenzyme electrophoresis was used to investigate the taxonomic relationships between species aggregates of Trichoderma isolated from antisapstain field trials and to identify physiological differences between 30 isolates of Trichoderma which show tolerance to MBT at concentrations ranging from less than 4 ppm to 34 ppm. Results indicate that there is considerable variability in the preservative tolerance of different Trichoderma isolates from particular locality. This highlights the need for field testing of an antisapstain compound in the same locality and under the same conditions in which it will be used in practice.
R J Wallace, R A Eaton, M A Carter, G R Williams

Soil treatment tests with the three products of boric acid for the prevention of the hyphal growth of Serpula lacrymans
1992 - IRG/WP 92-3693
Laboratory soil treatment tests were conducted for the evaluation of fungicidal or fungistatic effect of boric acid products against Serpula lacrymans. Boric acid products tested were the following three: a thickened boric acid solution in triethanolamine, boric acid-silica gel complex granules, and a nonwoven fabric laminated with a polypropylene film and coated with boric acid granules on one side surface. Effects of these products were evaluated using ezomatsu (Picea jezoensis) wood blocks and Kanuma soil or unsterilized sandy loam as a soil substrate. The thickened boric acid solution exhibited the sufficient efficacy to suppress the hyphal growth and decay of wood with boric acid retention of 2.0 kg/m³ in Kanuma soil medium. The perfect effect of the boric acid-silica gel complex granules was shown with boric acid retention of 3.0 kg/m³. The hyphal growth of the fungus was almost inhibited by placing the nonwoven fabric with boric acid granules over the media incubated with the fungus.
S Doi, A Yamada, Y Mineki, M Mori

Characterization of Poria indoor brown-rot fungi
1995 - IRG/WP 95-10094
The heterogeneous group of "Poria" fungi causing brown rot in buildings and also of wood in ground contact comprises Antrodia vaillantii, Antrodia serialis, Antrodia sinuosa, Antrodia xantha and Tyromyces placenta. These fungi have similar morphological appearance and biology. Their nomenclature has a confusing history and is still not uniform. As a consequence, misinterpretations may occur. SDS polyacrylamide gel electrophoresis showed a species-specific protein pattern for different cultures of Antrodia vaillantii separating the species from the other pore fungi as well as from Coniophora puteana and Serpula lacrymans. Electrophoresis also detected misidentifications. Investigations on growth rate, response to temperature, copper tolerance and wood decay revealed: Radial growth extension reached from 4 to 9 mm/d. Temperature optimum was 25 to 31°C. All withstood 1 hour at 60°C and some even 3 h at 65°C. Antrodia vaillantii was copper tolerant up to 0.05 M Cu. Wood weight loss after 20 weeks was higher by Tyromyces placenta (35%) and Antrodia sinuosa (33%) than by Antrodia xantha (21%), Antrodia serialis (16%) and Antrodia vaillantii (14%). Dual cultures revealed various inter- and intraspecific interactions and detected identity of differently coded cultures of a species. The former Poria vaporaria sensu Liese 'Normstamm II' for testing wood preservatives and the recent Poria placenta EN 113 strain FPRL 280 were shown to be either identical or at least sister monokaryons originating from the same individual.
O Schmidt

Characterization and differentiation of wood rotting fungi by protein and enzyme patterns
1999 - IRG/WP 99-20177
Standardized tests for wood preservatives are performed with defined fungal strains to ensure comparability between laboratories. However, changes of virulence and variation of results are well known events. Suitable and reliable measures to control the stability of the test organisms are necessary.Comparison of protein patterns produced by SDS-electrophoresis was already described by several authors as a possible way to identify and to characterize fungal species and strains, i.e. for Serpula, Coniophora and Poria. We compared protein patterns of several strains of Antrodia vaillantii, Poria placenta, Gloeophyllum trabeum, Lentinus lepideus, and Coniophora puteana. Isoelectric focussing and detection of esterase isoenzymes proved to be an alternative method. The investigations resulted in species-specific protein and enzyme patterns. By comparing the strains of single species it was possible to form groups with similar patterns. Possible misidentifications could be detected. The described methods will be further developed and used to follow possible changes in our test strains.
U Schoknecht

Direct analysis from wood of the blue stain fungi Aureobasidium pullulans and Hormonema dematioides by denaturing gradient gel electrophoresis
2006 - IRG/WP 06-10595
Aureobasidium pullulans and Hormonema dematioides are the two organisms used in the EN 152 laboratory method for determining the effectiveness of preservatives against blue stain in service. The literature concerning the disfigurement of surface coatings and exposed timber in-service states that A. pullulans is the dominant blue stain fungus, due to its frequent isolation from stained material. Inaccuracies when differentiating morphologically between isolates of these two related species have previously been highlighted bringing the conclusion concerning the dominance of A. pullulans to question. PCR-DGGE has been used to determine the environmental profile of the two blue stain fungi; A. pullulans and H. dematioides and to establish which of these organisms is most prevalent on a range of stained timber samples taken from trials and in service. The DGGE analysis indicated that a member of the Dothioraceae family, most likely H. dematioides was more commonly present on stained timber samples under five years old. No blue stain fungi were detectable by PCR-DGGE in older samples over 25 years old. With the correct primer choice PCR-DGGE is able to differentiate between different species and the level of abundance at which those species are represented in a sample. It is clear from this study that A. pullulans is not as dominant on stained timber as would have been expected. On this basis it is suggested that H. dematioides should be the preferred species for research and development work in this field.
M J Ray, D J Dickinson

Characterization of protein patterns from decayed wood of loblolly pine (Pinus taeda L.) by proteomic analysis
2008 - IRG/WP 08-10654
The primary biotic decomposers of wood belong to the basidiomycetes. The members of this group can attack and biodegrade both wood in the forest and in service. By the time wood decay is visible, there has already been a significant loss of strength. The identification of basidiomycetes and other organisms on wood only tell us what is present, not what is actively decaying the wood. When organisms are metabolically active, such as during wood decay, they produce proteins, some of which are unique to the decay process. Detection and identification of the fungal proteins involved in wood biodegradation would be an advantage in helping to understand the complex biodegradation pathways. In this study, we concentrated on proteomics as a tool to decipher biodeterioration-linked proteins. Proteomic analysis of fresh wood (southern yellow pine), decayed wood, inoculated decayed wood, and Gloeophyllum trabeum were performed. More than 170 proteins from four treatments were visualized on Commassie-stained two-dimensional polyacrylamide gels with a high resolution and reproducibility. These protein spots were subjected to in-gel digestion with trypsin for peptide fingerprint analysis by MALDI-TOF-MS. The tryptic peptides were identified with the aid of a BLAST homology search which found 76 unique proteins from inoculated decayed wood. No proteins were detected from fresh wood. Over 110 proteins were visualized from Gloeophyllum trabeum grown in culture. Among the proteins identified were oxidative enzymes and hydrogen peroxidases. Only actin was identified from decayed wood, but inoculated decayed wood contained wood degradation proteins such as alcohol oxidase, lipoxygenase, and catalases.
Young-Min Kang, L Prewitt, S Diehl

Effectiveness of sol-gel treatments coupled with copper and boron against subterranean termites
2009 - IRG/WP 09-30493
Wood modification by sol-gel treatments shows many positive features, like antimicrobial properties. Wood was also successfully modified with alkoxysilanes enhancing its resistance against soil micro-organisms. Silver, copper, zinc compounds, boric acid or organic biocides such as alkylammonium compounds may be added to the sol-gel to enhance its biocidal properties. Nevertheless, if some of these active ingredients and compounds are not fixed into wood by chemical reactions, they can be easily leached out by water. To overcome this limitation, a system based on silica sol-gel material starting from alkoxysilanes has been functionalized with organic groups having copper linking function. Sol-gel was also coupled with boric acid. As preliminary tests against the brown rot agent Coniophora puteana (Schumacher ex Fries) gave good results, the sol-gel formulations were also tested for their efficacy against subterranean termites. A no-choice test was set up, in two different time scales. Results show that though the sol-gel treatments act in very different ways, all of them are efficacy against subterranean termites. The total mortality occurred in the longer test suggested that active ingredients may be added in lower quantity.
E Feci, L Nunes, S Palanti, S Duarte, G Predieri, F Vignali

Nano structural properties of La2O3-Beech Wood Flour With XRD technique
2012 - IRG/WP 12-40607
This research was considered to study various properties of the Lanthana mixed with beech wood flour (BWF), as a new structure. For this purpose, La2O3 powders in the BWF have been obtained by sol-gel method using simultaneous gelation of all cations. La2O3 - BW samples are analysed by X-ray diffraction .The obtained results showed the formation of nano crystalline La2O3 phases. The average crystallite size is calculated by using X-ray diffraction analysis. It indicates that the difference in La2O3 behavior in the complex wood matrix may be due to chemical and physical interactions between La2O3 and lignins in the wood, or the presence of considerable amounts of inorganic cations in the sample.
M Ghorbani Kokandeh, I Bahamni, A Bahari

Study of in-situ gel polymerization established by Si-O-Si framework within wood micropores
2014 - IRG/WP 14-40672
Sodium silicate was used to form Si–O–Si framework by gel process and optimize the effect of the methylolurea impregnation on poplar wood. The modifier cured within the wood micropores by in-situ gel polymerization during the kiln drying. The results showed that treated wood acquired higher mechanical strength, but lower hygroscopicity. New positions of the XRD peaks appeared which caused by silicate sodium indicated that, modifier polymerized as kind of crystal within wood fiber amorphous areas. FT-IR analysis showed that the wood–OH, Si–OH from Si–O–Si framework and N–CH2–OH from methylolurea could reacted with each other to form C–O–Si bond and C–O–C bond. TEM showed that the Si–O–Si framework were embeded averagely in impregnated modifier. SEM-EDX analysis showed that the modifier remained ranging from a thin layer on the cell walls to big props filling the lumen.
Zeng Bi, Qian Lang, Heyu Chen, Junwen Pu

Polyamidoamines (PAA) functionalized with siloxane fragments as potential wood preservatives
2015 - IRG/WP 15-40708
Polyamidoamines (PAAs) utilized in this research were obtained by the reaction between N,N-methyl-bis-acrylamide (MBA) and Ethanolalmine (EtA) and/or aminopropytriethoxysilane (APTES). Different combinations between them were tested as wood preservatives against fungal decay. First, in situ impregnations of PAAs, with the reagents above described in different ratio, were performed and the effectiveness against C. puteana, through an accelerated mini-blocks test and EN 84 were determined. After the previous described screening test where the more promising formulations resulted those with the siloxames fragments, APTES and EtA were tested against three different fungi, C. puteana, T. versicolor and P. placenta through EN 113 and EN 84 tests. The EN 113 test showed that PAAs, functionalized with APTES alone, can be utilized as potential wood preservatives especially when the wood is not exposed directly to the leaching due to the rainfall.
S Palanti, G Predieri, E Feci, L Bergamonti

Biocidic effect of nano metal fluorides against brown-rot fungi
2019 - IRG/WP 19-30732
Metal fluoride nanoparticles are promising because of their low water solubility, which reduces the need for fixatives required in widely used active ingredients in wood preservatives such as copper and boron. The effectiveness of nano metal fluorides was compared to sodium fluoride treated wood samples. Wood specimens treated with homo-dispersed sols of MgF2 and CaF2 were tested against brown-rot (Coniophora puteana) fungi in accordance with standard EN 113. The sols were synthesized using fluorolytic sol-gel synthesis. The mass losses in leached sodium fluoride treated wood samples when exposed to brown-rot fungi was higher than 5%. However, leached nano metal fluoride treated samples exhibited mass losses below 1%. It was found that the combination of MgF2 and CaF2 had a synergistic effect on inhibiting the growth of fungi on wood. Thus, the fluoride introduced into wood in the form of nanoparticles was effective against brown-rot fungi even after leaching and without the use of fixatives.
S M Usmani, K Klutzny, I Stephan, E Kemnitz

Monitoring uptake and penetration of pesticides during impregnation of pine (Pinus sylvestris) and spruce (Picea abies) wood with bio-based microemulsion gel formulations
2020 - IRG/WP 20-30756
Even in dry state wood is susceptible to biological degradation. Preservation against biological decay in exposed conditions is conventionally achieved by impregnating the wood with pesticides applied at professional and industrial levels. Impregnation of wood with preservatives is a complex process that involves wood macro- and microstructure, and the physical characteristics of woods. Here we focused on pine (Pinus sylvestris), an easily impregnable species, as opposed to spruce (Picea abies), a refractory species. In this work, the two species were impregnated with commercial bio-based emulsion formulations containing insecticide and fungicide agents. Penetration and uptake of the active agents were evaluated on laboratory specimens. The impact of different modes of application, dipping, surface spraying, and vacuum-impregnation, on the retention and distance of penetration of the active agents, cypermethrin, permethrin and propiconazole was assessed by gas liquid chromatography coupled to mass spectroscopy. Due to the suitable combinations of solvents and surfactants of our bio-based emulsions of low-toxicity and minimal environmental impact, rapid wood penetration enabled high retention yields. The difference of penetrability of pine versus spruce is discussed in relation to their anatomical characteristics, and their conducting cells network. The present data demonstrate the penetration and retention performances of these bio-based formulations.
D Messaoudi, K Ruel, J-P Joseleau