Your search resulted in 80 documents. Displaying 25 entries per page.
Soft-rot control in hardwoods treated with chromated copper arsenate preservatives. Part 3: Influence of wood substrate and copper loadings
1977 - IRG/WP 2100
The hypothesis is proposed that hardwoods need more chromated copper arsenate (CCA) than softwoods to protect them from soft-rot attack mainly because hardwoods are more readily consumed by soft-rot fungi. Simple model systems, using copper-supplemented agar or groundwood pulp treated with CCA showed that fungi tolerated more toxicant (copper) as more available substrate (malt) was provided. Soft-rot tests with CCA-treated hardwood blocks provided typical dosage-response curves when results were expressed as a ratio of substrate to toxicant (wood to copper). Furthermore, hardwoods needed 10 to 20 times more copper as CCA than softwoods to prevent soft-rot attack. When CCA was substituted by ammoniacal copper arsenate in 5 hardwoods, similar threshold values for soft-rot attack were obtained in terms of a wood-to-copper ratio. Hence, CCA may be behaving poorly against soft-rot fungi in our hardwood specimens mainly because the substrate contained too little copper. The practical implications of these results are discussed.
M A Hulme, J A Butcher
Fungitoxic effect of the quaternary ammonium compounds preservatives against Basidiomycetes by using agar-plate and agar-block methods
1996 - IRG/WP 96-30118
Results of investigations on the fungitoxic value of three versions of wood preservatives based on the quaternary ammonium compounds (lauryldimethylbenzylammonium chloride, lauryldimethyl-benzylammonium bromide and alkylbenzyldimethylammonium chloride) and borates in relation to the wood destroying fungi have been presented. The agar-plate (screening) and agar-block method were applied. A wide range of the fungitoxic activity of all the three formulations and a very small leachability were proved.
J Wazny, P Rudniewski
Screening wood preservatives: Comparison of the soil block, agar block and agar plate tests
1993 - IRG/WP 93-20001
Several test procedures have been developed over the years to screen potential biocides for their value as wood preservatives. Each test has inherent advantages and disadvantages. In this paper the relative merits of the soil block, agar block and agar plate tests are compared. Eight commercially available biocides encompassing inorganic and organic systems were tested against four basidiomycete decay fungi. Each biocide was ranked according to its performance in the three tests. The results show that the relative efficacy of the different biocides is dependent on the screening test. Biocides can be separated on the basis of their chemistry. "Fixed" inorganic preservative systems perform better in tests which employ wood as a substrate material. Organic systems perform well in both the agar plate and wood-containing tests. Furthermore, the agar plate technique shows promise for detecting synergism between biocide components. It is concluded that all of these test methods should be considered to efficiently screen biocides for use as wood preservatives.
K J Archer, D D Nicholas, T Schultz
Fungitoxic effect of the quaternary ammonium compounds wood preservatives against the Ascomycetes and Deuteromycetes
1997 - IRG/WP 97-30138
Results of investigation on fungitoxic value of the three formulations of wood preservatives based on the quaternary ammonium compounds (lauryldimethylbenzylammonium chloride, lauryldimethylbenzylammonium bromide, alkylbenzyldimethylammonium chloride) in relation to the surface wood colouring (moulds) and soft-rot fungi have been presented. The agar-plate (screening) and agar-wood plate for moulding fungi and vermiculite-block methods for soft-rot fungi were applied. A high effectiveness of the formulations was proved.
J Wazny, P Rudniewski
Current state of world standardization in the toxicometric methods for testing of wood preservatives
2007 - IRG/WP 07-20354
The paper presents an outline of the history of forming standardized toxicometric methods for testing of wood preservatives in the world during last 100 years. Numerous studies resulted in three main methods which are currently used for official and basis assessment of biocides: - agar-block method in Europe (EN 113); - soil-block method in the USA and Pacific countries (ASTM D 1413); - modified soil-block method in the Russian Federation and the Commonwealth of Independent States (GOST 16712). Further on the paper compares the three methods and presents lines of their global standardization.
Activity of Two Strobilurin Fungicides Against Three Species of Decay Fungi in Agar Plate Tests
2017 - IRG/WP 17-30704
The objective of this study was to examine the toxicity of strobilurin fungicides against wood decay fungi in order to assess their potential to act as a co-biocide for copper-based wood protection. Two strobilurin fungicides, Heritage (50% azoxystrobin active ingredient) and Insignia (20% pyraclostrobin active ingredients), and copper sulfate pentahydrate were tested against one white rot fungus (Trametes versicolor) and two brown rot fungi (Gloeophyllum trabeum and Fibroporia radiculosa). SHAM (salicylhydroxamic acid) was also included in the study because it is a known potentiator of strobilurin activity. All treatments were incorporated in an agar-based media and evaluated for their effects on mycelial growth rate. Based on minimum inhibitory concentration values found for F. radiculosa (a copper-tolerant fungus), Insignia was 5.5x more toxic than Heritage. SHAM at 100 ppm, increased toxicity 9x for Heritage and 1.2x for Insignia. In a 20-day toxicity screening study, the four one-compound treatments tested were: copper sulfate (5000 ppm), Heritage (20 ppm), Insignia (20 ppm) and SHAM (100 ppm). The two two-compound treatments were: Heritage + SHAM and Insignia + SHAM. The two three-compound treatments were: copper sulfate + Heritage + SHAM and copper sulfate + Insignia + SHAM. For the two copper-susceptible fungi (T. versicolor and G. trabeum), the treatments that caused complete growth inhibition were copper sulfate alone and the two three-compound treatments (copper sulfate + Heritage + SHAM and copper sulfate + Insignia + SHAM). For F. radiculosa, the two- and three-compound treatments were the most toxic, with maximum daily average growth rates statistically similar to the copper sulfate treatment. A key result, however, was that only the three-compound treatment of copper sulfate + Insignia + SHAM completely inhibited growth of the copper-tolerant fungus. Thus, it appears that pyraclostrobin, which is the active ingredient in Insignia, has greater potential than azoxystrobin to act as a co-biocide for completely inhibiting growth of a copper-tolerant fungus.
J D Tang, T Ciaramitaro, M Tomaso-Peterson, S V Diehl
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
Spore germination of Gloeophyllum trabeum on wood is related to the mass of the wood sample
1978 - IRG/WP 2118
E L Schmidt, D W French
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
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
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
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
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
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
Preliminary screening of diffusion formulations for the control of soft rot
1978 - IRG/WP 2104
We have an urgent need in Australia to develop in situ remedial treatments for the present population of in-service transmission poles. For various reasons we have opted for formulations which can be applied as bandage treatments and thus we are primarily concerned with assaying diffusable toxicants. Two basic approaches have been made: an assay of the formulation's toxicity; and a combination assay of the formulation's diffusibility and toxicity. Of the direct assay methods the filter-paper technique is the more rapid although with highly soluble formulations some leaching of toxicants will occur during the preparatory stages and probably during incubation also. Furthermore, filter papers are not strictly comparable to wood, and a modification we have considered is to use 'papers' prepared from mechanically beaten pulps rather than chemically degraded pulps. An additional modification would be to substitute veneers for filter papers, although this may give rise to surface concentration effects since the veneers could prove difficult to impregnate homogeneously. By far the most valuable technique for our own screening programme of potential toxicants to control soft rot in standing poles is the Petri dish/wood slab technique. While agar diffusion systems are rapid and provide valuable 'short list' data, the information obtained on diffusion rates cannot easily be applied to solid wood. Da Costa's slab technique is obviously advantageous in this respect. Furthermore, it can be so tailored that successive inocula can be sequentially assessed, thereby providing added information on component diffusion as well as total formulation movement. However, care must be taken in interpreting the data since it is not possible to distinguish directly which chemicals in a mult-component formulation have diffused first and hence which are the toxic ones. Similarly, it could be necessary to impose a time restriction on the test with certain types of formulations.
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
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
Isolation and identification of the fungal flora in treated wood
1976 - IRG/WP 144
J F Levy
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.
The effect of malt and agar trademarks on growth, decay and stilbene resistance of fungi
2000 - IRG/WP 00-20202
Effects of malt and agar trademarks used in growth media on growth of fungi in cultures, amount of decay they cause in birch samples and their resistance to stilbenes were tested. It was tested also had the conditions where fungus cultures were stored before inoculation of test plates some effect on the results. Fungi used in these tests were white rot fungus Trametes versicolor and brown rot fungus Piptoporus betulinus. Stilbenes used were pinosylvin and resveratrol. The tested trademarks of agar had no effect but trademarks of malt had statistically significant effect on growth, decay and resistance to stilbenes. Storage conditions of cultures before tests had less effect on results, they effected mainly when the growth conditions during test were unfavourable to the fungi.
L Syrjälä, L Paajanen, A Pappinen