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Effects of the specimen position on fungal colonisation and wood decay by en 113 test fungi
1998 - IRG/WP 98-20136
For testing wood preservatives according to EN 113 it is common practice to plant the test blocks on neutral supports in order to prevent (1) a diffusion of chemicals into the agar medium and (2) an excessive moistening of the specimens. The procedure was employed in EN 350-1 for testing the natural durability of solid wood. It turned out to be of problematic nature because of the individual requirements of the test fungi. A certain degree of moisture can stop the virulence of one species, but - on the other hand - favour the virulence of another, so that different ratings of durability can be expected. In order to clarify this relation, blocks of durable and non-durable wood species were planted on different support materials and directly on the mycelial mat. Coniophora puteana, Coriolus versicolor, Gloeophyllum trabeum, and Poria placenta were used as test fungi. The results reveal a wide range with respect to the rate of colonisation and decay of the respective wood species if supports or no supports are used.
G Kleist, M-T Lenz, R-D Peek


Accelerated testing for out of ground contact using natural biological preconditioning: Part 2
1997 - IRG/WP 97-20108
Small blocks of scots pine sapwood were treated, buried in vermiculite and exposed to natural microbial colonisation during outdoor exposure prior to laboratory decay testing. An EN 84-type leach trial was carried out on unexposed samples. Periodic microbial isolations, moisture content, permeability and weight loss tests were also conducted. The experiment ran for 12 months. The colonisation of the miniblocks by micro-organisms was rapid and different patterns of colonisation were observed for differently treated miniblocks. The dominant organisms throughout were Alternaria sp., Fusarium sp., Curvularia sp., Aureobasidium pullulans, Phialophora sp. and bacteria. Weight losses of 10% occurred in the field by 12 months with untreated samples. DDAC- and TnBTO-treated miniblocks (at the recommended commercial retention) had weight losses of 7% and 8% respectively. ACQ treated samples at this retention had the lowest weight losses at only 1.5%. Of the treated samples, TnBTO-treated blocks had the most rapid rate of weight loss and also the fastest increase in permeability. TnBTO-and DDAC- treated samples had equivalent final permeabilities, at double the value of the ACQ-treated blocks. The decay trial indicated that this natural pre-exposure method was very severe with reduced performance of all treatments in the monoculture Basidiomycete tests after 12 months of pre-exposure. The comparative leaching trial showed that the failure of the preservatives was not due only to severe leaching in the test system. The white rot decay test indicated that at all retentions TnBTO- and DDAC-treated miniblocks had reached over 3% weight loss by 3 months pre-exposure but for ACQ this weight loss was not reached until 12 months. In the brown rot test at all retentions of TnBTO and ACQ weight losses of over 3% were reached by 3 months and for DDAC by 6 months.
S Molnar, D J Dickinson, R J Murphy


Comparison of the agar-block and soil-block methods used for evaluation of fungitoxic value of QAC and CCA wood preservatives
1994 - IRG/WP 94-20039
The modyfied agar-block and soil-block methods were used for comparing the fungitoxic value of QAC and CCA type preservatives against Coniophora puteana and Coniophora olivacea The mass loss and moisture contents of wood were analysed.
J Wazny, L J Cookson


Biological control of Serpula lacrymans using Trichoderma spp
1994 - IRG/WP 94-10069
The effectiveness, or otherwise, in killing Serpula lacrymans, of a range of Trichoderma spp. in a variety of media and using two different incubation systems has been tested. In agar based systems with normal nutrients or minimal nutrients with high or low nitrogen contents and high or low iron content Trichoderma harzianum 25 proved to be the most efficient and killing Serpula lacrymans. Other species, such as Trichoderma hamatum 150, were effective in some media but not in others. Initial observation on partially decayed small wood blocks suggested that actively growing Serpula lacrymans could not be killed by Trichoderma spp.. Experiments undertaken on a specially designed system, however, indicated that certain Trichoderma spp. can act as effective antagonists even in wood based systems.
A J Score, J W Palfreyman


Essais mycologiques sur poteaux traités à la Wolmanit C B
1974 - IRG/WP 339
D Ollier, C Jacquiot


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


Effect of sterilization method on germination of spores of wood decay fungi observed by contact agar block method
1978 - IRG/WP 2117
Previous studies of germination of spores of wood decay fungi on wood have generally concluded that method of wood sterilization has little significant effect on germination response. This study expands the numbers of test fungi as well as number of sterilization methods employed to determine the influence of sterilization method on spore germination response of decay fungi. Germination was assessed on agar discs fused by aqueous diffusion path to 1 cm³ samples of aspen and white spruce sapwood.
E L Schmidt, D W French


Study of the natural durability and impregnability of a metropolitan species of tree
1986 - IRG/WP 2261
The current and predictable evolution of construction timber supply conditions is motivating research for a more efficient utilization of native woods. It is now important to determine statistically reliable impregnability values on a national scale, and to evaluate the natural durability of woods recently introduced in France, or economically important native woods.
M E Mathieu


Determination of toxic limits of wood preservatives towards wood-destroying Basidiomycetes. Investigation on the effect of the use of two impregnated wood blocks and of one impregnated and an untreated block respectively in Kolle jars on the toxic limits of wood preservatives
1973 - IRG/WP 225
O Wälchli


Some experiments with hexabutylditin against fungi
1977 - IRG/WP 388
The investigation was carried out in 1972 and 1973 to collect experimental data about the poisonousness of hexabutylditin (HBDT) against the woodrotting fungi Coniophora puteana (Coniophora cerebella), strain 15, and Chaetomium globosum, strain hexabutylditin was being manufactured by the Organisch Chemisch Instituut (O.C.I.) TNO, at Utrecht.
J W P T Van der Drift


New conception for shortering the duration of fungitoxic test on wood preservatives. Part 1: State-of-art
1994 - IRG/WP 94-20044
The review of agar-block and soil-block methods published during 90 years focused of shortening the duration of fungitoxic test of wood preservatives is presented. Special attention was given to miniaturisation of wood specimens.
J Wazny, P Witomski


Sub-group on Basidiomycete tests: Proposals for Sub-group programme of work
1979 - IRG/WP 2127
During the IRG 10 Meetings in Peebles, Scotland in September 1978, it was resolved to establish within Working Group II a sub-group on testing wood preservatives against basidiomycete fungi. The terms of reference and scope of the sub-group's activities were to be determined by consensus among members who registered an interest. Dr A F Bravery (PRL, UK) was asked to act as co-ordinator. During the course of the Peebles Meeting the following members registered their intention to participate: Dr D Aston (UK), Dr C Coggins (UK), Mr G Fahlstrom (USA), Professor D French (USA), Professor C Jacquiot (France), Mr B Jensen (Denmark), Dr A Ofusu-Asiedu (Ghana), Miss J Taylor (UK). Since there was insufficient time to convene an inaugural meeting in Peebles the present paper has been prepared as a basis for discussions and to facilitate initiation of active collaboration. It is hoped that members will offer individual comment in order to define the desirable scope of the sub-group's work and to refine ideas for collaborative or co-ordinated experimental work.
A F Bravery


A laboratory evaluation of the susceptibility to biological attack of glued laminated pine timber
1991 - IRG/WP 2387
In the scope of a research programme concerning the use of maritime pine (Pinus pinaster) to produce glued laminated timber structures in Portugal, the natural durability of this material was checked by using laboratory test methods. An European standard, EN 113, was used to test durability against basidiomycetes and a test method developed at LNEC for termites was adapted for this purpose. From the results obtained, it seems that the existence of glue layers does not influence the natural durability of the material under basidiomycetes attack. As for termites the method used indicates that they are unable to cross the glue layers though this effect would hardly be of importance for practical uses.
L Nunes, H Cruz


New conception for shortering the duration of fungitoxic test of wood preservatives. Part 3: Proposal for interlaboratory test on miniaturisation of wood specimens
1994 - IRG/WP 94-20053
In connection with documents IRG/WP 94-20044 and IRG/WP 94-20052 the proposal for interlaboratory test on miniaturization of wood specimens is given.
J Wazny, J J Krajewski


The proposal for optimalization of the agar-block method for wood preservatives fungitoxic evaluation
1995 - IRG/WP 95-20065
On the base of own research and other scientists results the proposal for optimalization of agar-block method was presented by: - selection of test fungal species and strains and central distribution of their pure cultures, - change of the treatment and control samples exposure procedure, - application of mathematical estimation of toxic value results, - shortening the duration of fungitoxic test by miniaturization of wood samples.
J Wazny


The variability of preservative distribution in test blocks
1973 - IRG/WP 220
The techniques for the assessment of likely effectiveness of preservative systems have long been the subject of much discussion. The whole field has recently been reviewed by Hilditch and Hamblyn (1971) who described in detail many of the laboratory test procedures used, but who also indicated the deficiencies in many of these techniques. It has long been the view of many associated with the wood preservation industry that laboratory tests can only serve as a preliminary method of screening and that final approval by both the company marketing the development and independent authorities, on whom the burden of approval rests, can only be given after detailed testing in the field. The aim of the simple piece of work described in this paper, is to lok at the variability which one might expect in the distribution of preservative in test blocks destined for laboratory fungal evaluation.
F W Brooks, M R Gayles, R W Watson


The use of plastic meshes in soft rot monoculture testing
1990 - IRG/WP 2353
Plastic meshes were introduced between the wood blocks and agar medium in a miniaturised soft rot monoculture test in order to minimise transfer of the preservative from the wood and mineral salts from the agar. Although several different sizes and types of mesh were used and the blocks were wetted up to an appropriate moisture content for soft rot attack the amount of decay was substantially reduced compared with the controls. Addition of mineral salts to the wood blocks in similar quantities to those in the agar aided decay but did not provide suitable conditions for maximum loss in weight.
S M Gray


Comparison between agar-block and soil-block methods for wood-destroying Basidiomycetes
1992 - IRG/WP 92-2401
The object of this work is to compare these methods in order to provide some information to help in the choice between them. The comparison was made by a statistical analysis (factorial completely randomized design) and by a discussion about other aspects of each method. An evaluation of some fungi on attacking wood and a comparison between Picnoporus sanguineus isolated from carpophore and decayed wood were made. The results indicated that the loss of mass was greater in soil-block. Besides, the activity of the fungi in this method was more homogeneous than in agar-block. However the soil-block method presents some difficulties not found in the agar-block method. As related to the performance of Picnoporus sanguineus strains, the greater loss of mass occured when it was isolated from carpophore, no matter what method was used. These results give important indications about the biological characteristics and the source of the strains.
M B B Monteiro, S Brazolin, G Catanozi


Assessment of the toxicity of some copper-, zinc- and boron-based wood preservatives to the cellar fungus Coniophora cerebella Schröet
1974 - IRG/WP 242
This article reports the use of a method based on the determination of the probability of the protection of timber against destruction by fungi. By converting the probability values to probit values and plotting them as a function of the amount of preservative retained in the timber, curves of the toxic effect are obtained, enabling any timber protection probability to be assessed.
V N Sozonova, D A Belenkov


Fungi used in standard tests on the toxicity value of wood preservatives in various European countries
1975 - IRG/WP 255
The aim of the present paper is to make the comparative analysis of test fungi used in various European countries in order to define the toxicity value of wood preservatives against fungi of the Basidiomycetes class. Only the methods with national standard rank, present on the currently binding standards list are taken for consideration. The analysis of similarities and differences in the choice of test fungi used in these methods should be a further step in the investigation on the unification of the test methods
J Wazny


Some data on the activity of alternative fungicides for wood preservation
1985 - IRG/WP 3333
Data from laboratory tests against basidiomycete fungi are presented for 9 alternative fungicides in organic solvent formulations and also in water for one product. Results are compared with data for reference preservatives, tributyltin oxide, copper and zinc naphthenates and pentachlorophenol. Of special interest is the apparently better than additive effect of mixing tributyltin naphthenate and Xyligen B, and the promising performance of Armoblen 480, a novel organic solvent formulation of n-alkyl coco-derived quaternary ammonium compounds.
A F Bravery, J K Carey


Preliminary results of the treatment of wood with chlorosilanes
1981 - IRG/WP 3172
It is clear from the initial data reported here that the treatment of pine sapwood with chlorosilanes under the reaction conditions employed did not significantly reduce the decay by both white rot and brown rot fungi. Only the dichlorosilane compounds showed to possess some protective action against fungal attack. Before drawing conclusions on the application of organosilicon compounds as potentially alternative wood preservatives much more work is needed. At present the anti-blue stain activity of the different types of chlorosilanes is being tested. Further investigation on the treatment is also required with respect to the effect of wood moisture content and the use of other types of acid acceptor on the silylation reaction. Current studies also deal with the effect of the treatment on physical and mechanical properties of wood. The initial physical tests on the sorptive and dimensional behaviour of treated wood revealed that the dichlorosilanes might give better results again.
M Stevens


Hygroscopicity of decayed wood - Implications for weight loss determinations
1996 - IRG/WP 96-20085
Hygroscopicity changes were observed in red maple blocks subjected to brown rot, white rot and soft rot. Brown rot reduced hygroscopicity, soft rot increased hygroscopicity, and white rot showed only a very slight increase in hygroscopicity. The effect of these changes on weight loss tests is a slight overestimation of weight loss for brown rot and a slight underestimation for soft rot and white rot. Hygroscopicity changes were similar prior to and after oven drying for white rot and soft rot, while for brown rot, the reduction in hygroscopicity was enhanced by oven-drying.
S E Anagnost, W B Smith


Resistance of various wood species against decay by Coniophora cerebella (Pers) Duby and Lenzites trabea (Pers) Bres
1976 - IRG/WP 142
Both fungi, Coniophora cerebella and Lenzites trabea, are important destroyers of timber. Coniophora often occurs inside buildings and Lenzites trabea has been observed on southern facades of buildings, on balconies and window frames. In most instances that we investigated coniferous timber had been decayed. But both species are known to attack also various hardwoods. For this reason tests similar to those carried out with Serpula lacrymans (see O. Wächli, Holz als Roh- und Werkstoff, 31, (1973) 96-102), have been made with both fungi on various home-grown and foreign wood species.
O Wälchli


Evaluation of bacteria for biological control of wood decay
1990 - IRG/WP 1426
Laboratory soil-block and agar-block tests were carried out to evaluate the efficacy of bacteria as biological control agents against 5 brown-rot and 3 white-rot fungi. Pretreatment of Southern pine and sweetgum with a bacterial solution prevented decay in agar-block tests. However, the bacteria were generally ineffective in preventing decay in Southern pine, Douglas-fir, sweetgum and yellow poplar in soil-block tests. Wood blocks treated with an autoclaved bacterial solution were not decay resistant by either test method.
R Benko, T L Highley


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