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Black Stain of Western red-cedar by Aureobasidium pullulans and its Relationship with Tropolone Depletion
2005 - IRG/WP 05-10564
Western red-cedar is valued for its natural durability conferred by fungicidal tropolone chemicals. However, weathered surfaces of WRC products are still susceptible to ‘black stain’ caused by fungi such as Aureobasidium pullulans. The effect of weathering on the tropolone content of heartwood was characterized and correlated with the ability of this fungal species to colonize the same weathered surfaces. UV plus water spray severely reduced tropolone content but did not lead to increased fungal colonization compared to un-weathered wood. When WRC was treated with UV only, the tropolone content was less affected but the fungal colonization increased significantly. A.pullulans exhibited high tolerance to the tropolone β-thujaplicin in vitro; thus loss in tropolone content may not be required for colonization. In addition to UV resistance from melanization and ability to use lignin breakdown products as a carbon source, resistance to tropolones may confer considerable competitive advantage to A.pullulans growing on WRC exposed to weather. The application of water spray most likely washed away products of lignin photo-degradation, leaving the wood surface void of accessible carbon sources which resulted in decreased colonization.
R Chedgy, R Daniels, P I Morris, C Breuil


Reducing Extractives Stain in Western Red Cedar Sidewall Shingles
2014 - IRG/WP 14-30654
One of the aesthetic challenges that western red cedar shingles face is extractives redistribution stain, particularly in unpainted sidewall applications. Dip and pressure treatments with a mixture of quaternary ammonium compounds and alkyl amine oxides were investigated for their ability to prevent this stain. After nine months of exposure in Vancouver, extractives stain was present on nearly all untreated shingles, but was greatly reduced in incidence and intensity on both the dip- and pressure-treated shingles. Longer-term potential benefits (increased durability) and risks (accelerated weathering) of these treatments should be investigated.
R Stirling


The effect of certain wood extractives on the growth of marine micro-organisms
1977 - IRG/WP 438
S E J Furtado, E B G Jones, J D Bultman


Screening potential preservatives against stain and mould fungi on pine timber in Zimbabwe
1995 - IRG/WP 95-30063
The search for environmentally and toxicologically safer chemicals for use in the timber preservative industry against stain and mould fungi has been intensified during the past few years. Results of field tests with two chemicals previously evaluated in the laboratory are presented. The conventional sodium pentachlorophenate was the more efficacious chemical against stain and mould fungi, providing up 90% control at a concentration of 2.5%. A potential alternative, Stopstain a borate-based chemical, gave results only slightly better than the untreated control timber, at a concentration of 5%. Unless the environmental cost and toxicological hazards of traditional chemicals are highlighted the newer and safer chemicals will be reluctantly accepted by industry as they are regarded as being prohibitively expensive.
A J Masuka


Blue stain in service on wood surface coatings. Part 3: The nutritional capability of Aureobasidium pullulans compared to other fungi commonly isolated from wood surface coatings
1993 - IRG/WP 93-10035
The nutritional capability of Aureobasidium pullulans was previously examined, using agar plate tests, with regard to nutrient sources that are potentially available in fresh and weathered wood (Sharpe and Dickinson, 1992). This study compared these findings with the nutritional capability of four other fungi (Alternaria sp., Cladosporium cladosporoides, Stemphylium sp. and Trichoderma sp.) commonly isolated from wood surfaee coatings. The liquid culture techniques were used to assess the relative abilities of the fungi to utilise a range of simple sugars, wood sugar alcohols, hemicelluloses, cellulose and lignin degradation compounds. The observations were used to explain why Aureobasidium pullulans is able to occupy so successfully, often in monoculture, the wood-paint interface niche.
P R Sharpe, D J Dickinson


Low temperature drying conditions of Pinus radiata wood for avoiding internal stain
1989 - IRG/WP 3507
It has been observed that, if in little sawmills, timber is dried with a low temperature schedule, it arrives at destination with internal sapstain besides of superficial mould. In this study, the lowest drying temperature at which wood should be exposed for sterilization, which results to be 52°C, is searched. It is not possible to avoid entrainment of pentachlorophenol, even though a waiting period of 72 hours after dipping the wood in a pentachlorophenate/borax solution before drying is considered. The residual content of pentachlorophenol in wood should be at least 400 µg/cm² or the moisture content less than 23% for avoiding the development of mould.
M C Rose


Report on the activities of the European Standardization Committee CEN/TC 38 'Methods of Testing wood preservatives'
1980 - IRG/WP 279 E
G Castan


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


Mould resistance of lignocellulosic material treated with some protective chemicals
1984 - IRG/WP 3294
Effectiveness of preserving lignocellulosic material against moulding by treatement with water solutions of commercial wood preservatives and mixtures of various inorganic salts was investigated and compared with the effectivenes of sodium pentachlorophenoxide and boric acid.
K Lutomski


Field trials of anti-sapstain products. Part 1
1991 - IRG/WP 3675
The results obtained in two field tests of anti-sapatain products, carried out in four locations in Portugal, are presented. Boards from freshly cut logs were hand-dipped, close staked and left to dry for periods from four to six months. The results obtained seem to indicate that some of the products tested performed at least as well and sometimes better, than a 3% NaPCP solution which was used as control product.
L Nunes, F Peixoto, M M Pedroso, J A Santos


Evaluation of the effectiveness of three microbiocides in the control of sapstains
1982 - IRG/WP 3212
Results of field test on the effectiveness of BUSAN 30, CAPTAN, FOLPET against mould and sapstain in Pinus elliottii are presented. The viability of use of FOLPET in Brazil as an alternative to sodium pentachlorophenate is also discussed.
S Milano, J A A Vianna Neto


Rapport sur l'activité du CNE/TC 38 'Méthodes d'essais des produits de préservation du bois'
1980 - IRG/WP 279
G Castan


Proposed standard laboratory method for testing fungicides for controlling sapstain and mould on unseasoned lumber
1977 - IRG/WP 292
This laboratory method is for determining the effective concentration, or concentration for zero growth (CGo), for fungicides or preparations of fungicides which are potentially useful in protecting packaged or unseasoned lumber in storage and shipment from biodeterioration by sapstain fungi and moulds. The test is rapid and may be completed in three weeks and gives a good indication of the toxicity of a chemical against sapstain fungi and moulds.
A J Cserjesi


Tebuconazole, a new wood-preserving fungicide
1990 - IRG/WP 3634
TEBUCONAZOLE, an anti-fungal triazole compound, has been tested to assess the effectivness as wood preserving fungicide. Tests were made with the active ingredient and also in formulations against basidiomycetes, blue-staining fungi and mould. Results of the DESOWAG laboratories and also from official institutes will be presented. In addition to this there were made different toxicological and ecotoxicological trials according to OECD and EPA guidelines
B Wüstenhöfer, H-W Wegen, W Metzner


Blue stain in service on wood surface coatings. Part 2: The ability of Aureobasidium pullulans to penetrate wood surface coatings
1992 - IRG/WP 92-1557
The ability of Aureobasidium pullulans to penetrate seven different wood surface coatings was examined. Eight isolates of Aureobasidium pullulans were used. Following penetration, light microscopy was used to examine the effect of the fungus upon the coating, and growth at the wood-film interface. The fungus showed different growth capabilities with different types of surface coatings. Some isolates were able to penetrate alkyd based coatings, but were unable to grow in the film. In contrast, after penetration through latex based coatings several isolates were able to produce growth in the films themselves.
P R Sharpe, D J Dickinson


Methodology challenges in developing a transfer of natural durability from sawmill residues, illustrated by experiences with white cypress (Callitris glaucophylla)
2000 - IRG/WP 00-20203
The transfer of durability-conferring extractives from durable to non-durable wood has been accomplished often, but usually as an educational exercise rather than as a commercially oriented process. In the latter environment, many factors previously overlooked become vitally important. How to study them, in the absence of well-developed methodology and given the shorter timeframes being demanded by industry research funding organisations, presents real challenges. These challenges will be illustrated by experiences with the development of such a process for the 'waste' durability components of white cypress. Factors to be considered include: identification of active components; quantification of their individual and collective activities against target organisms; optimisation of source material handling, storage and extraction techniques; extract standardisation and batch-to-batch reproducibility; compatible yet cost-effective carriers for the actives into treated wood; effects on durability and other wood properties such as strength and handling safety; regulatory obstacles including acceptance into wood preservation standards; and quality control methods for penetration and retention of the treated product.
M J Kennedy, M A Powell


Blue-stain fungi (Ceratocystis spp.) found in Spain on pine woods
1989 - IRG/WP 1410
So far, there is only a very limited reported description of the different Ceratocystis spp. present on fresh wood in Spain. So, the main goal of this work has been the identification of species of this genus causing blue-stain on Pinus pinaster A. Ait. and Pinus sylvestris L. woods. We have also investigated the relationship between the species found and their propagation vectors (insects and wind). Finally, we have determined the growing velocity of two of the most representative species found and the presence or absence of degradative enzymatic activities.
M T De Troya, A M Navarrete


Blue stain in timber in service. Results of co-operative tests to compare different artificial weathering systems 1981-82
1983 - IRG/WP 2193
The paper describes results of the third phase of co-operative laboratory experiments comparing the effects of different artificial weathering systems on chemicals to control blue-stain in service. Atlas, Xenotest and Marr equipments are shown to give essentially the same results for 5 of the 6 chemicals tested.
A F Bravery, D J Dickinson


Rapport sur l'activité du CEN/TC 38
1983 - IRG/WP 2204
M Pottevin


Working Group II: Sub-group: Methods of testing anti-stain chemicals for protecting sawn lumber during storage, transit
1978 - IRG/WP 2121
R Smith


Rapport sur l'activité du Comité CEN/TC 38 "Méthodes d'essais des produits de préservation des bois" du Comité Européen de Normalisation (CEN)
1986 - IRG/WP 2266
G Castan


Rapport sur l'activité du CNE/TC 38 'Méthodes d'essais des produits de préservation du bois'
1977 - IRG/WP 288
G Castan


Relationship between stacking, location and antisapstain preservatives on visible degrade of Eucalyptus regnans and Pinus radiata boards
1999 - IRG/WP 99-20162
An antisapstain trial was established at a Eucalyptus hardwood sawmill in Victoria, Australia. The trial incorporated two commercial formulations of antisapstain preservatives, used at four different concentrations on both hardwood (Eucalyptus regnans F. Muell) and softwood (Pinus radiata D. Don) boards. The trial also utilised different stacking methods (block-stacked, sticker-stacked, and block-stacked and wrapped in black plastic) and included replicates placed both outside in the drying yard, and inside under cover from the elements. The variation in stacking methods and in location was used to provide a variation in the fungal hazard. Worst degrade (mean of 83% at 36 weeks) was obtained for the hardwood block-stacked outside and wrapped in black plastic. Lesser extents of degrade were obtained for sticker-stacked hardwood outside (4.3%) and sticker-stacked hardwood under cover (1.2%). Degrade of softwood was less than that of hardwood under all conditions. Statistical analysis of the trial indicated that the probability of any individual hardwood board deteriorating outside was nearly 4 times greater than for a board kept undercover. In addition, the probability of degrade of a hardwood board which was block-stacked and wrapped in black plastic was 3.4 times that of a hardwood board which was block-stacked but not wrapped, which in turn was 10 times that of a hardwood board which was sticker-stacked. The probability of degrade in untreated hardwood timber was 20 times that of degrade in preservative-treated hardwood timber, with variations in preservative concentration having an insignificant effect. Over all conditions the probability of hardwood timber deterioration was 5 times that of the softwood. The results of this trial confirmed that timber stored closely stacked and under poorly ventilated conditions suffered a higher visible degrade, as expected for sapstain fungi. However, although preservatives effectively reduced visible degrade under all storage conditions and at all concentrations tested, selection of correct storage conditions was also an important part of minimising degrade.
J Snow, P Vinden, S M Read


Tentative method of testing wood preservatives against blue staining
1977 - IRG/WP 259
The blue stain of sawn wood is still a real problem in Poland. Although a preservative based on sodium orthophenylphenoxide has been introduced into sawmill practice, and the technology of wood protection developed with it, new information has been obtained concerning blue stain in wood material destined for export. In order to select new chemicals or to improve the effectiveness of the ones in current use it is necessary initially to carry out laboratory tests of the prepared chemicals to determine their efficiency.
E Tarocinski, O Lewandowski, M H Zielinski


Efficacy of some extractives from Pinus heartwood for protection of Pinus radiata sapwood against biodeterioration. Part 1: Fungal decay
1995 - IRG/WP 95-30072
Chemical compounds thought to contribute to the natural durability of heartwood of Pinus spp. were either chemically synthesised in the laboratory or extracted from the heartwood of Pinus elliottii or Pinus caribaea. These compounds included the stilbenes, pinosylvin and its mono- and di-methyl ethers, and the flavonoids, pinobanksin and pinocembrin. Small blocks of Pinus radiata sapwood were impregnated with methanolic solutions of pure compounds or heartwood extracts, to a range of retentions extending above and below the concentration of each compound known to occur in the heartwood of Pinus spp.. Fungicidal efficacy of these compounds has been evaluated by exposure of treated blocks to pure cultures of a white and a brown rot, in addition to an unsterile soil test.
M J Kennedy, J A Drysdale, J Brown


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