Your search resulted in 91 documents. Displaying 25 entries per page.
Durable fibre for durable MDF – testing Tricoya®
2015 - IRG/WP 15-40704
The chemical modification of wood has been a commercial reality for a decade on release of technologies for the modification of solid wood including Accoya®. A challenge and an opportunity for the modification technologies which typically impart dimensional stability, water stability and enhanced biological durability was the adaptation of the technology to wood based panels. This paper presents a summary of the development of Tricoya®, its testing and performance and examples of applications.
E Suttie, J Alexander, M Maes
The 46th Annual Meeting of IRG. Poster abstracts
2015 - IRG 15-60378
Annual Report 2014
2015 - IRG 15-60376
Agenda 2015 Plenary Meeting
2015 - IRG/WP 15-60377
Budget for 2015 (forecast May 2015)
2015 - IRG/WP 15-60380
Budget for 2016
2015 - IRG/WP 15-60381
Reporting minutes of the Plenary Meeting 2015
2015 - IRG/WP 15-60390
Programme. The 46th Annual meeting of the International Research Group on Wood Protection (IRG46)
2015 - IRG/WP 15-60379
IRG Documents 2015
2015 - IRG 15-60391
Influence of the moon phase on durability against wood decay fungi of Larix kaempferi and Pseudotsuga menziesii wood species
2015 - IRG/WP 15-10836
The analysis of the natural durability of wood is essential when establishing the level of protection required, depending on the designated end use of timber. On the other hand, there is a popular belief based on the influence of the moon phase in felling timber, recommending the waning moon as the optimum for felling trees. In fact, some companies now offer among their products, sawn timber felled in the proper moon phase (moon wood).The aim of this work was to study the possible influence of felling during the waxing and waning moon phases, on the durability of Larix kaempferi (Lam.) Carr. and Pseudotsuga menziesii (Mirb.) Franco, (wood destined for structural use) against the wood decay fungi Basidiomycetes (Coniophora puteana (Schumacher ex Fries) Karsten and Postia placenta (Fries) sensu Cooke J. Eriksson). Durability is established using weight loss standardized assays using sapwood and heartwood of each species, cut during both lunar phases. The results show that neither species is durable against the fungi studied, however, significant differences between the two phases are observed. This study corroborates many traditional beliefs within the wood sector
M T Troya, M Conde, M J Barriola, F Llinares, V Dorronsoro
The role of hydrophobins in surface growth by the Blue Stain fungi Aureobasidium pullulans
2015 - IRG/WP 15-10837
Hydrophobins are small proteins found exclusively in filamentous fungi. These proteins are able to assemble spontaneously into amphiphilic monolayers at hydrophobic–hydrophilic interfaces. Hydrophobins have a diverse role, e.g. allowing the fungi to break through interfaces during aerial hyphae formation, sporulation, fruit body production and cell penetration. In this ongoing study, we are looking at the role of hydrophobins in the fungal ability to adhere to different substrates. We hypothesize that hydrophobins have a positive effect on the fungi by reducing the surface tension and assisting fungal growth of aerial hyphae and colonization of the fungi between humid and dry areas.The Blue Stain filamentous fungus, Aureobasidium pullulans, represents a common mold in the nature, commonly known to have a huge role in the attack of wood treated and untreated surfaces like commercial wood products. As Aureobasidium pullulans is also known to produce hydrophobins, a specific aim of this study includes the analysis of the impacts of hydrophobins on mediating surface growth of Aureobasidium pullulans on exterior wood coatings (e.g. wood paints). At least two gene sequences encoding hydrophobins in Aureobasidium pullulans were identified, both to be successively disrupted by integrating a recycled selectable marker into the open reading frames of the genes, creating a double knock-out mutant strain, using homologues recombination. In this study we will present our work and strategies for identification and clarification of the role of hydrophobins, which future wise can lead to new kind of Blue Stain controllers.
J Stenbæk, L Riber, J Blæsbjerg Nielsen, C Møller Hansen, B Jensen
Field Performance of Old-Growth and Second-Growth Western Red Cedar Fence Posts with and without Barrier Wraps
2015 - IRG/WP 15-10838
Many authors have suggested natural durability may be lower in second-growth western redcedar than in old-growth. One potential means of offsetting a decline in durability is use of physical barriers to separate the wood from soil. In the present work we compared the durability of old-growth and second-growth western red cedar posts, with and without barrier wraps, in a field test. After ten years, two non-wrapped old-growth posts and one non-wrapped second-growth post failed a push test; no wrapped posts failed. Non-wrapped posts had mean decay ratings of 7 for both old-growth and second-growth, while wrapped posts had mean decay ratings of 8 and 9 for old-growth and second-growth, respectively. This suggested that wrapping may extend service life. There were minimal differences between old-growth and second-growth decay ratings. This result can be attributed to the minimal differences between measured extractives.
P I Morris, J K Ingram, R Stirling
Interpretation of moisture monitoring data - Relevance of moisture content thresholds for fungal decay
2015 - IRG/WP 15-10839
It is widely accepted that besides temperature wood moisture content (MC) is the key factor when it comes to durability of wooden structures exposed to weathering. Many approaches to predict the service life of wooden structures have therefore been based on using wood MC as one major input-variable to develop dose-response relationships between material climate and decay response. However, to improve these approaches and to model the decay and service life of timber structures more precise information about the minimum MC threshold for the onset and development of fungal decay are needed. MC thresholds determined in two different studies have shown that different fungi were able to degrade wood clearly below fiber saturation. This data has been summarized in the present paper and applied to moisture monitoring data recorded in above ground tests. Different thresholds were comparatively used for quantifying the moisture induced risk for decay. The results have shown that setting material-specific MC thresholds determined in a pile test led to a remarkable higher number of wet days with critical MC compared to commonly used MC thresholds.
L Meyer, C Brischke
Investigations on the durability of several Congo basin wood species
2015 - IRG/WP 15-10840
The sawdust of ten wood species was studied to assess their natural resistance to decay. The extractives and lignin contents were primarily determined (between 2.7-16.0% and 26.8-35.9% respectively) to give an overview of the chemical distribution. Then, a phytochemical screening (colorimetric methods) characterized the different chemical functional groups in all extracts studied. Antioxidant activity indicated values comprised between 18 and 175 µmol AAE/µg of extract correlated to total phenolic content which were comprised between 51 and 935 mg eq. of gallic acid/g of extract. The resistance to decay of extracted and unextracted sawdust against the two white-rot fungi was evaluated and showed that extractives amounts and compositions partially influenced wood durability.
S Mounguengui, J-B Tchinda Saha, M Kor Ndikontar, S Dumarçay, C Attéké, D Perrin, E Gelhaye,
Chemical composition of extractives of different wood compartments of Pinus merkusii and their potential implication in wood durability
2015 - IRG/WP 15-10841
Amounts and nature of extractives differ strongly according to the compartment of wood and to the nature of the wood species. Previous studies reported that knotwood of several European Pinus sp. contains extractives contents much higher than stemwood consisting mainly of lignans which may find valuable applications in cosmetic, nutraceutic or pharmaceutic sectors. Different explanations have been proposed to explain these high amounts of lignans: the first one concerns their potential implications in the lignification process to reinforce knot tissues involved in branches support; the second one their role in wood durability and protection against biotic and abiotic agents. During the course of our studies concerning the identification of new sources of molecules with potential interest, we were interested in the characterization of knotwood extractives of Pinus merkusii a tropical wood species for which no data on the nature of extractives have been reported up to now. Determination of extractives amounts present in sapwood, heartwood and knotwood of Pinus merkusii has been performed and their chemical composition analyzed using GC-MS and LC-MS. Antioxidant and antifungal activities were also evaluated by DPPH method and growth inhibition method, respectively. The results showed that knotwood contains more extractives than heartwood, the latter containing more extractives than sapwood. Knotwood extracts contain mainly lignans, especially nortrachelogenin, stilbenes and resin acids, while heartwood extracts were constituted mainly of stilbenes, especially pinosylvin monomethyl ether, pinosylvin and pinosylvin dimethyl ether and of flavonoid like pinocembrin. Acetone knotwood extract presents the higher antioxidant activity, while acetone heartwood extract possesses the higher antifungal activities against the two tested fungi Trametes versicolor and Poria placenta.
A Wijayanto, S Dumarçay, R Kartika Sari, W Syafii, P Gérardin, C Gérardin-Charbonnier
Effects of UV Radiation on Melanization and Growth of Fungi Isolated from Weathered Wood Surfaces
2015 - IRG/WP 15-10842
This research tests the hypothesis that fungi isolated from weathered wood will respond to elevated levels of UV radiation by increasing their melanin production. To test this hypothesis, we measured the melanin production and mycelial color of Aureobasidium pullulans and Cladosporium cladosporioides, before and after the fungi were grown under artificial UV, visible light and complete darkness. Two albino fungi: A. pullulans and Ophiostoma piliferum, and one pigmented O. piliferum fungus were used as controls. Our results show that A. pullulans has the ability to increase its production of melanin when exposed to UV radiation. This adaptive response may protect A. pullulans from the high levels of UV radiation found at wood surfaces exposed outdoors. C. cladosporioides was highly melanized, irrespective of exposure to different light sources. Our findings suggest that the discoloration of weathered wood surfaces may be influenced by the response of fungi colonizing wood surfaces to UV radiation. Further research is needed to test this hypothesis.
V A Hernández, P D Evans
Short-term protection of palm wood against moulds and decay fungi by environment-friendly organic acids
2015 - IRG/WP 15-10843
Felled palm trunks are susceptible to fungi as long as their moisture content is above fibre saturation. During this period, it has to be protected against moulds and decay fungi. The study tested environmental-friendly organic acids for their protecting efficiency. Small samples of Date palm (Phoenix dactylifera) and Oil palm (Elaeis guineensis) wood were treated with weak organic acids and subsequently infected by moulds and wood-decay fungi. Short dipping of the samples in solutions of 5% acetic acid and propionic acid, respectively, protected all samples for two months from colonization by Aspergillus niger, Penicillium sp., Cladosporium sp., and by a natural infection. Boric acid (4%) used in practice for protection was ineffective. Decay tests with the white-rot fungus Pleurotus ostreatus, the brown-rot species Coniophora puteana and the soft-rot fungus Chaetomium globosum showed that both acids prevented most samples from fungal colonization and reduced decay considerably during two months.
M Bahmani, O Schmidt
Study on Biological Distribution to Conserve the Tripitaka Koreana woodblocks in Haeinsa Temple
2015 - IRG/WP 15-10844
Tripitaka Koreana is the Wood-carved Buddhist scriptures which were made in 13th century. And Janggyeong Panjeon that is depository for the Tripitaka Koreana was built in 15th century. In recent days, biological damage becomes a serious problem to wooden cultural heritage including historical wooden buildings with global warming. In this study, termite monitoring on whole Haein-sa temple area and distribution investigation of insect and microorganism around Janggyeong Panjeon were conducted to make up basic data for heritage conservation and management.
Si Hyun Kim, Hyun Ju Lee, Yong Jae Chung
Glutathione transferases and wood extracts
2015 - IRG/WP 15-10845
Wood rotting fungi have developed an efficient detoxification system allowing them to be well adapted to their way of life, these fungi generating and encountering potential toxic compounds during wood degradation. Belonging to this detoxification network, glutathione transferases are particularly extended in these fungi and their presence could reflect the chemical environments encountered by the fungi. To test this hypothesis, we developed biochemical assays to quantify interactions between wood extracts and glutathione transferases from from two white-rot fungi: Trametes versicolor and Phanerochaete chrysosporium. The obtained preliminary results reported in this paper demonstrate that GSTs from white-rot fungi could be used to discriminate wood extracts from different origins in accordance with their chemical compositions.
A Deroy, F Saiag, Z Kebbi-Benkeder, N Touahri, M Morel-Rouhier, F Colin, S Dumarcay, P Gérardin,
Remote sensing for detection of termite infestations—Proof of Concept
2015 - IRG/WP 15-10846
This paper reports the results of a search to discover the most cost effective and robust method of detecting Reticulitermes flavipes infestations in structural members of remote bridges, homes and other wooden structures and transmitting these results to internet cloud storage thus obviating routine travel to these structures for periodic visual inspections. Duplicate stainless steel tanks were constructed for housing R. flavipes colonies and commodity size dimension lumber members. Overall, results indicated that the simplest and cheapest independent variables to measure and send were: temperature (ºC), relative humidity (% RH); dew point (DPºC) and wood moisture content (WPE %) using off-the-shelf commercially available sensor systems. Above ground termite bait stations were determined to be the best method of housing the various sensors to permit ease of subsequent baiting if any termite activity was detected. We conclude that it is feasible and cost effective to monitor valuable wooden structures, like historic covered bridges, against termite infestation and potential structural damage.
F Green III, R A Arango, C R Boardman, K J Bourne, J C Hermanson, R A Munson
Effects of geographical and dietary variation on the symbiotic flagellate protists communities of the subterranean termite Reticulitermes grassei Clément
2015 - IRG/WP 15-10847
Despite their importance on diverse ecosystems, termites may also be considered severe pests of wood in service, and also as agricultural and forestry pests. Subterranean termites’ ability to digest lignocellulose relies not only on their digestive tract physiology, but also on the symbiotic relationships established with flagellate protists and bacteria. In this tripartite lignocellulolytic system, the termite contribute with endogenous cellulases and mechanical processing, flagellate protists phagocyte the wood particles and digest them, and prokaryotes have, among others, an important role in maintaining the physical-chemical equilibrium inside the termite hindgut. The flagellate protist community living inside the termites is rather diverse, as there is a strong division of labour among them to accomplish the intricate process of lignocellulose digestion. The objectives of this work were to: 1) investigate the changes in flagellate protists communities of the termite Reticulitermes grassei in different locations; 2) test the possible effect of different laboratorial diets on diversity and abundance of the flagellate protists. R. grassei termites were captured in four different locations (Évora, Faial Island, Leiria and Sesimbra), in Portugal, and their symbiotic flagellate protist community diversity and abundance was evaluated. Termites belonging to the same colony were submitted to six different diets (natural diet, pine wood, European beech, thermally modified beech, cellulose and starvation) and after the trials their flagellate protist community was also evaluated. The differences between termite colonies from different locations may not be denied, although not considered to be significant. Similar flagellate protists communities were found on non-treated sound woods, while cellulose fed and starving termites had significantly different communities. The flagellate protists community of untreated beech and thermally modified beech fed termites were considered to be significantly different, with three morphotypes missing in the treated wood fed termites. Although the effects of geographical location were not considered significant, the laboratory diets caused major adaptations of the flagellate protists communities. The termite symbiotic flagellate protists community is a dynamic assemblage able to adapt to different conditions and diets.
S Duarte, M Duarte, P A V Borges, L Nunes
Toxic effect of Melia azedarach L. unripe fruit extracts onto Reticulitermes flavipes Kollar (Isoptera: Rhinotermitidae)
2015 - IRG/WP 15-10848
The subterranean termite, Reticulitermes flavipes Kollar (Isoptera: Rhinotermitidae), is part of one the major biotic agents which damage wood and it is a pest in several countries, where the economic losses are huge. In Chile there have been foci of infestation in the Metropolitan Region and in the Region of Valparaíso with a big expansion in the last years. This study evaluated in laboratory the direct toxic effect of extracts from Melia azedarach L. (Meliaceae) unripe fruits onto R. flavipes workers. The extracts were elaborated from two solvents, distilled water and ethanol. The toxic effect was determined with direct exposure tests to the extracts. The mortality caused by several concentrations of aqueous and ethanol extracts. The extracts from the unripe fruits of M. azedarach were effective as an insecticide agent against R. flavipes workers, with the greatest mortality at the highest concentrations, and better effects of the ethanol extract than the water one. The results obtained verify toxic effect of extracts from the unripe fruits of M. azedarach as a bioinsecticide for R. flavipes, thus, this tree could become a promising alternative source of a bioinsecticide for use in a management program for this pest.
A Huerta Fuentes, B Rubio Díaz, Í Chiffelle Gómez
Natural durability of Chilean commercial wood exposed to the action of marine borers
2015 - IRG/WP 15-10849
Results of field experiences of natural durability of ten commercial wood, exposed to the action of Bankia martensi (Stempell) in the South coast of Chile are presented. Tested species were seven types of native wood and three types of exotic ones. Test specimens of standard dimension of 0.02 x 0.045 x 0.23 m with three replications by species were used. The degree of attack was determined according to British norm BS IN 275:1992. Differences in the degree of attack between the wood species and basic properties such as the anatomy, density, hardness and percent extractives were analyzed. After six months of exposure, test specimens were inspected. The response of wood species without protective treatment was in general poor considering the brief lapse of exposition, since all of them were damage, except Quillaja saponaria Mol. Externally, the attack did turn out to be only superficial with orifices of 0.002 to 0.003 m and also abundant organisms were adhered to the surface. The presence of numerous galleries and individuals of mollusc bivalve Bankia martensi (Stempell, 1899), belonging to Teredinidae family, was verified inside the wood specimens.The species that shows minimum indications of attack is Drimis winterii J.R. et G. Forster, with galleries covering in average 0.44% of the surface of the test specimens; Prosopis tamarugo Phil. follows with moderate attack (16.06% of the affected surface); attack severe appeared in: Laurelia philipiana Looser and Pinus radiata D.Don with galleries occupying 29.40 and 32.90% of the area respectively. Failed, with more of a 50% of the surface covered with galleries were: Eucalyptus globulus Labill (52.53%); Pseudotsuga menziesii (52.02%), Nothofagus dombeyi (Mirb.) Blume. (52.58%), Saxegotea conspicua Lindl. (53.82%) and Nothofagus alpina (Poepp. et Endl.) Krasser, the last one reaching 90.95% of its surface covered with galleries
R Carmona C, C Osorio, A Almuna
Repellency of Schinus molle L. leaf extracts onto Reticulitermes flavipes Kollar (Isoptera: Rhinotermitidae)
2015 - IRG/WP 15-10850
Reticulitermes flavipes Kollar (Isoptera: Rhinotermitidae), is a subterranean termite which damage wood and it is a pest in several countries, where the economic losses are huge. In Chile there have been foci of infestation in the Metropolitan Region and in the Region of Valparaíso with a big expansion in the last years. This study evaluated in laboratory the repellence effect of extracts from Schinus molle L. (Anacardiaceae) new leaves onto R. flavipes. The extracts were elaborated from two solvents, distilled water and ethanol. The repellency effect was determined by a direct selection test, in which the average of contact termites with treated and no treated filter paper disks with extracts prepared simultaneously was calculated, and the results were subjected to comparison paired tests. Obvious repellence effect from S. molle to R. flavipes was shown by the extracts, especially ethanolic. Both extracts revealed a greater effect with increasing concentration. The results demonstrate the effectiveness of the extracts from S. molle in the repellence effect onto R. flavipes, so that leaf tree species could be considered in biopesticide preparation for integrated management of this pest, previous field evaluation and economic study.
A Huerta Fuentes, S Constenla Cáceres, Í Chiffelle Gómez
An update on durability of New Zealand grown timber
2015 - IRG/WP 15-10851
Classification and predication of in-service performances of naturally durable timber is much more difficult than preservative treated timber due to the variability of wood properties within and between trees of the same species and the variable nature of the hazard to which the timber will be exposed. A combination of field test and in-service testing has been used to classify the suitability of New Zealand locally grown timber for various end-uses and to show that they are a suitable substitute for preservative treated timber. Suggested uses of the species, their suitability to meet the requirements of NZS 3602:2003 and likely limitations are discussed.
D Page, T Singh