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Effect of felling time related to lunar calendar on the durability of wood and bamboo -Fungal degradation during above ground exposure test for 2 years- (Preliminary report)
2005 - IRG/WP 05-20311
Current study was carried out to know whether the felling time of trees and bamboos based on lunar calendar affects natural durability of felled wood-bamboo or not. Each of one sugi (Cryptomeria japonica) tree of 28 years old and one Moso bamboo (Phyllostachys heterocycla) of around 3 years old was cut 12 times between February and December in 2003. Six sets of sugi tree and bamboo were felled in a day during “Hassen” period and the other 6 sets of them were also felled in a nearby non-“Hassen” day. There is a belief that “Hassen” should be avoided to perform destructive works such as cutting trees. “Hassen” lasting 12 days based on lunar calendar appears 6 times every year. After felling sample trees and bamboos, these specimens were subject to outdoor exposure at above ground level for 2 years. Properties of specimens such as moisture contents, mould and fungal resistance were examined periodically for 2 years. There was no clear difference in the degree of mould growth on the surface between specimens felled in a “Hassen” day and those felled in a non-“Hassen” day in the same month. The felling seasons, however, influenced the growth of mould on the surface of wood and bamboo clearly, which has been traditionally known in many cases. Fungal degradation evaluated by visual observation and the depth of pin penetration using Pilodyn during 2 years exposure was not affected by not only “Hassen” or non-“Hassen” also seasons when tree and bamboo felled.
K Yamamoto, S Uesugi, K Kawakami


Comparison of decay rates of preservative-treated stakes in field and fungus cellar tests. Results after 40 months fungal cellar exposure
1983 - IRG/WP 2200
Decay rates of preservative-treated Pinus radiata stakes during 40 months exposure in the FRI fungus cellar were compared with those of similarly treated material in a field test. Decay rates in the fungus cellar were from 4 to 100 times higher than in the field, although for the majority of preservatives the rate was between 7 and 12 times higher. The lag phase before onset of decay, noticeable with most of the preservatives in the field test, was largely eliminated in the fungus cellar. Possible reasons are given for inconsistencies in relative rates of decay of preservatives in the two tests.
M E Hedley


Bending creep test of plywoods under long term exposure to fungal attack
1981 - IRG/WP 2163
Bending creep test and decay test were coupled in order to evaluate the durability of structural plywoods and preservative efficacy. Experimental blocks, 5.0 x 1.2 cm² section x 35.0 cm length, were impregnated with distilled water and inoculated with mycelial fragments of test fungus. Polyethylene bags stretched with metal frame were used as decay chambers. The chambers containing inoculated blocks and water were plugged with porous silicone plugs. Weight was hanged from the center of block. The deflection at the center of span was measured with a gauge sensor connected with a recorder. The deflection due to fungal attack appeared after 800-1200 hrs incubation. Non-treated plywoods failed by 2400 hrs. Treated plywoods containing 1 kg/m³ of TBP (Tribromophenol) did not fail even after 3800 hrs but deflected continuously. When containing 5 kg/m³ of TBP, only a slight deflection was observed. Based on the assumption that decay advanced uniformly in the parallel direction to the span but wavy like as cosine curve in the perpendicular one, creep deflections were calculated and compared with the experimental ones. It may be concluded from these results that the method is promissing for evaluating the durability of structural board materials and preservative efficacy.
M Takahashi


Laboratory testing of wood natural durability - In soil-bed assays
1998 - IRG/WP 98-20141
Laboratory methods for assessing wood decay resistance are being investigated in the framework of an ongoing European research project. This paper summarizes the main results obtained for soil-bed tests based on the European prestandard ENV 807-Test 2. The data suggest that this testing methodology is suitable for evaluating the natural durability of timber species in soil-contact under conditions which promote soft rot. Results after 16 weeks of exposure were found to enable the assessment of wood durability. Both, mass and strength (MOE) loss determination proved suitable for hardwood testing. In contrast, only the MOE losses recorded for softwood species were correlated with their expected decay resistance. The lack of correlation between mass loss and durability data is likely related to the very slow decay rates found for softwood timbers in the soil bed. Furthermore, artificial weathering prior to testing was shown to affect the susceptibility of some timber species to soft rot decay. This suggests that a weathering step may be required prior to biological testing. Wood leaching by the protocol described in EN 84 deserves attention as a possible alternative to the very expensive and time consuming artificial weathering pretreatment. In conclusion, laboratory soil testing using a modified ENV 807-Test 2 methodology can be recommended for assessing the durability of timbers to be used in ground contact. Such tests can provide useful information to complement the results from basidiomycete tests. The potentials of basidiomycete tests based on EN 113 to assess the natural durability of timbers were also investigated. The main findings will be presented at this conference by van Acker et al. (1998).
R Sierra-Alvarez, I Le Bayon, J K Carey, I Stephan, J Van Acker, M Grinda, G Kleist, H Militz, R-D Peek


Artificial weathering exposure as an alternative for standard ageing according to EN 84 (leaching) and EN 73 (evaporation)
2002 - IRG/WP 02-20254
In order to verify potential weaknesses of wood preservatives fungal tests are carried out after ageing of wood preservative treated test blocks. The European standard EN 599 as a framework for efficacy assessment of wood preservatives includes the use of two ageing methods prior to fungal testing, namely a leaching method (EN 84) and an evaporation method (EN 73). The European research project "F.A.C.T." aimed amongst other objectives to provide in more realistic alternatives for both ageing methods. Artificial weathering systems generally used to assess the weathering resistance of exterior coatings was looked at as an alternative. For this purpose artificial weathering devices were selected which besides a control of temperature and light also allow for the impact of moisture by means of water spraying. UV cabinets with spray option were used to evaluate the effect of ageing of three wood preservatives: a waterborne Cu-HDO preservative, an oilborne triazole combination and a TBTO reference preservative. Based on EN 113 Basidiomycete testing of aged specimens a range of equivalent UVS systems proved to be suitable as an alternative ageing system prior to EN 84 and EN 73.
J Van Acker, M Grinda, D J Dickinson


International comparison of three field methods for assessing the in-ground resistance of preservative-treated and untreated wood to termites and fungal decay – Summary of observations after five years
2003 - IRG/WP 03-20261
Results are presented from a five-year study conducted in five locations in Australia, Thailand and the USA. Three methods of exposure were assessed (below-ground, graveyard and ground contact) for evaluating the in-ground termite and decay resistance of Pinus radiata D. Don sapwood stakes that had been vacuum pressure impregnated with CCA (Type C) and ACQ (Type D) each at two nominal retentions (2 and 4 kg/m3), and of outer heartwood stakes from five trees of the durable North American Baldcypress, Taxodium distichum (L.) Rich. The termite attack and fungal decay ratings, based on the loss of cross section of the stakes, declined more rapidly at the three tropical sites in southern Thailand (Phuket) and in northern Australia (Darwin) compared to the two more temperate sites in southern USA (Gulfport, Mississippi) and southern Australia (Griffith, New South Wales). Depending on the type of preservative treatment (detailed for termites only) the three different assessment methods yielded either similar trends (ACQ 2 kg/m3; baldcypress) or outcomes varied with site and method (CCA 2 kg/m3; CCA 4 kg/m3) or the three assessment methods could be ranked from most to least effective in the same sequence across all sites (ACQ 4 kg/m3). Treatments or type of timber elicited different responses from the local termite fauna (from readily contacted by termites to avoidance). These responses can be modified by the way specimens are presented to termites. Average [n = 15] termite attack ratings (1st value Australian, 2nd value ASTM rating) after 5 years in the tropics (T) and non-tropics (NT) were: CCA 2 kg/m3 T = 4.3/6, NT = 6.7/8; CCA 4 kg/m3 T =5.5/7, NT = 7.4/9; ACQ 2 kg/m3 T = 4.4/6 , NT = 6.9/9; ACQ 4 kg/m3 T = 5.4/7, NT = 7.1/9. Baldcypress was more durable in the USA and Thailand (slight attack) and least durable against Mastotermes darwiniensis Froggatt in Australia (moderate attack). Fungus decay ratings (1st value Australian, 2nd value ASTM rating) after 5 years were: CCA 2 kg/ m3 T = 5.1/7, NT = 7.9/9; CCA 4 kg/m3 T = 6.1/8. NT = 7.8/9; ACQ 2 kg/m3 T = 5.2/7, NT = 6.7/9; ACQ 4 kg/m3 T = 5.6/8, NT = 7.7/9. Baldcypress results varied with source tree and test method.
M Lenz, J W Creffield, T A Evans, B M Kard, C Vongkaluang, Y Sornnuwat, A F Preston


Influence of fungal exposure on the redistribution of copper in treated spruce wood
2002 - IRG/WP 02-10450
The redistribution of copper in treated wood after exposure to basidiomycete decay fungi is described. The micro-distribution of copper in copper(II) sulphate or copper(II) octanoate/ethanolamine treated Norway spruce wood before and after exposure to 3 different wood decay fungi was studied using transmission electron microscopy with X-ray microanalysis. The copper content of the mycelium and the nutrient medium was also determined by atomic absorption spectroscopy. Finally, light microscopic analyses of decayed samples was performed. Both copper-tolerant (Antrodia vaillantii) and copper-sensitive fungi (Trametes versicolor and Gloeophyllum trabeum) changed the distribution of copper in the treated wood after 16 weeks of exposure. The redistribution of copper in copper sulphate treated samples exposed to tolerant A. vaillantii was characterised by the excretion of oxalic acid and formation of copper oxalate in the cell lumens, on the surface of treated wood blocks and on the fungal hyphae. In the presence of ethanolamine, the formation of copper oxalate by A. vaillantii did not occur but instead diffusion of copper into regions of lower copper concentration (centre of the blocks and nutrient medium) took place. This type of redistribution/diffusion of copper was also observed when treated wood specimens were exposed to the copper-sensitive fungi.
M Humar, F Pohleven, R J Murphy, D J Dickinson, I Moris, M Zupancic, P Kalan, M Petric


Evaluation of fungal infestation and decay in a simulated use class 3 situation (block test) after some years of exposure
2012 - IRG/WP 12-20487
The so named “block test” was designed as part of the assessment methodology for testing the behaviour of natural and modified wood used under use class 3 (EN 335-2) conditions. The test was developed to expose the wood close to the ground to an environment with high humidity and high biological activity, but not in soil contact. The present study describes the evaluation of fungal infestation and decay of untreated samples in different blocks depending on their exposure time, positioning within the block and wood species. After 4 years outside exposure samples showed visible signs of decay. The highest rate of decay was visible in the middle layers of the block. After 7 and 8 years outside exposure, samples of all layers were infested with a similar intensity of different types of decay. The results have shown that in the bottom layer close to ground the major type of decay is white rot as well as white rot in combination with soft rot. In contrast, samples from the middle layers and top layer were infested mainly by brown and white rot but also soft rot was observed. The test setup is according the definition of use classes a method for use class 3 applications because the samples are out of ground contact. But the infestation of samples in all layers by soft rot indicated that under use class 3 test conditions but with elevated moisture conditions soft rot attack can occur and should make part of a proper test design.
A Gellerich, K Röhl, S Adamopoulos, H Militz


Changes of fungicidal, mechanical and sorption properties of wood during above ground outdoor exposure
2013 - IRG/WP 13-20513
The aim of this preliminary study was to investigate differences in mechanical, fungicidal, and sorption properties of four different wood species (sweet chestnut (Castanea sativa), common beach (Fagus sylvatica), Norway spruce (Picea abies), and copper-ethanolamine (CuE) impregnated Norway spruce (Picea abies)) that were exposed in the 3rd use class (CEN, 1992) for periods between 4 and 30 months. EN 113 laboratory test indicated an increased susceptibility of chestnut wood to fungal decay. After 12 weeks of exposure to brown rot Gloeophyllum trabeum mass loss of 4.3% was determined on samples that were weathered for 18 months. Results show no apparent deterioration in mechanical properties of chestnut and CuE impregnated spruce; however a 37% drop in bending strength is evident at beech wood after 30 months outdoors, and spruce wood lost around 15% of its bending strength in the same time. We find modulus of elasticity to be inappropriate for quick assessment of fungal decay.
N Thaler, M Humar


Resistance of fungal derived pigments to ultraviolet light exposure
2014 - IRG/WP 14-30642
The potential for using fungal derived pigments as surface treatments for limiting photodegradation of wood was investigated. Extracts from Chlorociboria aeruginosa and Scytalidium cuboideum were compared with a traditional aniline dye and chromic acid treatment. Hybrid poplar sapwood samples treated with these solutions were exposed to 86.4 kj/m2 of UV radiation and assessed for lignin degradation using FTIR attenuated total reflectance analysis. Both the fungal dyes and the aniline dye failed to protect lignin from photodegradation compared with control samples, while the chromic acid provided some protection. Assessment of indicator peaks for the dyes, however, revealed that some dye components were UV resistant. Although the dyes did not prevent UV degradation of the wood, they may be able to mask the color changing effects of weathering by remaining stable after UV exposure.
H G Beck, S Freitas, G Weber, S C Robinson, J J Morrell


Effects of fungal exposure on air and liquid permeability of nanosilver- and nanozincoxide-impregnated Paulownia wood
2016 - IRG/WP 16-30680
Effects of aqueous dispersion of silver and zinc-oxide nano-particles on air and liquid permeability of Paulownia wood exposed to T. versicolor were studied in the present research project. Specimens were also heat-treated at 100 and 150°C and compared with the control specimens. Permeability values were measured when the moisture content of the specimens was 12%. Results showed significant increase in air permeability after impregnation with either nanosilver or nanozinc. The increase in permeability was due to the breakage of tyloses under the high pressure in the impregnation vessel. However, significant decreases were observed in permeability in all treatments after the fungal exposure. The decrease was related to the growth and accumulation of hyphae along vessel lumens, blocking the path for fluid transfer. It was concluded that both heat-treatment at 150°C and the impregnation with zinc-oxide significantly inhibited growth of the fungus, consequently decreasing wood mass loss.
H R Taghiyari, A Kalantari, M Ghorbani Kookandeh, F Bavaneghi, M Akhtari


Estimation of wood degradation determined by visual inspection, mechanical testing and DNA characterisation – report after 3 years of exposure
2016 - IRG/WP 16-30700
The influence of two separate treatments, thermal modification and alkaline copper quaternary (ACQ, Silvanolin©) treatment, on fungal decay, visual disfigurement, deterioration in mechanical properties and fungal community structure was assessed on Norway spruce (Picea abies) and compared with the performance of two naturally more resistant tree species native to North America: Douglas fir (Pseudotsuga menziesii) and Western red cedar (Thuja plicata). Wood samples were exposed to environmental conditions and collected annually over three years. Samples were visually examined and rated for decay and disfigurement then evaluated to failure in three-point loading to determine flexural properties and, finally, DNA was extracted from the samples and analyzed to determine the fungal community present. As expected, there were substantial differences in visual ratings, fungal colonization and flexural properties. Further assessments are planned.
N Thaler, T Martinović, M Bajc, D Finžgar, H Kraigher, A Sinha, J J Morrell, M Humar


Identifying the fungal community on western redcedar (Thuja plicata) wood in field tests above and in ground contact exposure: preliminary results
2019 - IRG/WP 19-10939
Western redcedar (Thuja plicata) is a high value species in the Canadian forest industry due in large part to the natural durability of its heartwood. Western redcedar heartwood contains extractives that are inhibitory to the growth of many fungi responsible for decay. In order to gain insights into which extractives are important in long term durability, and which fungi are important to decay of western redcedar in service, we conducted a study looking at the fungal community on wood that has been in field tests and monitored for decay for many years. We sampled old growth and second growth western redcedar fence posts that have been in ground contact for 17 years, and deck boards that have been in an above ground test for 14 years. We performed DNA metabarcoding using Illumina sequencing and traditional culturing techniques to characterize the fungal community from samples. Preliminary results from both culture studies and DNA metabarcoding show a predominance of ascomycetes on decks. Basidiomycetes were more frequent on fence posts in the DNA metabarcoding data. The most widespread species detected from decks using DNA metabarcoding was a Hyaloscypha species and from the fence posts was the brown rot species Gloeophyllum sepiarium. The most common species isolated into culture and identified by DNA from the deck samples was the basidiomycete Pachnocybe ferruginea and from the post samples was the zygomycete Mortierella parvispora. Improving our understanding of fungal communities and the role they play in western redcedar decay as well as how they are affected by inhibitory extractives can help in the improvement or development of new wood protection systems, as well as to inform breeding programs aiming to develop seedling stock with enhanced natural durability
A Dale, S Kus, R Stirling


A comparison of soft rot, white rot and brown rot in CCA, CCP, CCF, CCB, TCMTB and benzalkonium chloride treated Pinus radiata IUFRO stakes, after 9-15 years exposure at five test sites in New Zealand
1991 - IRG/WP 1485
The aim of this study was to determine if decay type varies significantly between five field trial test sites of different soil type, aspect and climate in 9-15 year old, replicate CCA, CCF, CCP. CCB, TCMTB and AAC treated IUFRO stakes. A visual on-site assessment of decay type on every test stake was made and observations confirmed by microscopical examination. Regression analyses were used to determine significant differences of percentage frequency of occurrence of each rot type between sites and preservatives. Large differences in percentage frequency of occurrence of rot type were evident between sites. One site was dominated by brown rot (85%) and two were dominated by soft rot (99 and 91%). The fourth site had intermediate proportions of brown rot (40%) and soft rot (71%) but had the second highest occurrence of white rot (32%) (highest = 37%; lowest = 11%). The fifth site was distinct in that a large proportion of stakes (69%) had both well established brown rot and soft rot. Stakes at the other four sites tended to have only one rot type. Some highly significant preservative effects were also found. Possible causes of these differences are discussed in terms of inter-site soil type, climate and other differences.
R N Wakeling


Questionnaire - Fungal decay types
1985 - IRG/WP 1265
T Nilsson


Improvements of monitoring the effects of soil organisms on wood in fungal cellar tests
1996 - IRG/WP 96-20093
Accelerated testing the durability of preservative treated timber in a so called "fungal cellar" or "soil-bed" to evaluate its performance in ground contact is widespread practice. In order to obtain a more accurate and reproducible estimate of preservative performance, several institutes, among them the BAM in Berlin, have routinely carried out static bending tests in addition to visual examination. These tests were usually performed with a defined maximum load or deflection path regardless of the remaining degree of elasticity of the test specimens. Recent studies at the BAM revealed that by modifying the method, i.e. by restricting the applied load to the non-destructive interval for each individual test specimen, the calculated modulus of elasticity (MOE) reflect the changing strength properties caused by biological deterioration and allow within a relatively short time valuable predictions on the service life of the treated timber in soil contact.
I Stephan, S Göller, D Rudolph


The restricted distribution of Serpula lacrymans in Australian buildings
1989 - IRG/WP 1382
Temperature data has been gathered over a number of years, not only for flooring regions of various buildings in Melbourne, but also within roof spaces and external to the buildings. Findings are discussed in relation to the distribution of Serpula lacrymans within Australia, its restriction to certain types of building construction and its restriction to flooring regions. The subfloor spaces of badly-ventilated, masonry buildings are highlighted as being better suited than are the subfloor spaces of, for example, Japanese buildings for the activity of this fungus. Hence Serpula lacrymans is very restricted in its distribution in Australia, yet where it is active it does grow rapidly and causes rapid flooring failures.
J D Thornton


Fungal and bacterial attack of CCA-treated Pinus radiata timbers from a water-cooling tower
1991 - IRG/WP 1488
Transmission electron microscopy of decaying CCA-treated Pinus radiata timbers from an industrial water cooling tower showed presence of a thick biofilm covering some areas of the wood. The biofilm contained various morphologically distinct forms of microorganisms embedded in a slime. The study provided evidence of the activity of soft rot fungi and tunnelling and erosion bacteria in wood cells. The extent of damage to wood cells due to microbial activity varied, combined fungal and bacterial attack having the most damaging impact.
A P Singh, M E Hedley, D R Page, C S Han, K Atisongkroh


Co-operative research project on L-joint testing. Sampling after 8 months exposure
1983 - IRG/WP 2208
It was anticipated in Document No IRG/WP/2192 that exposure of L-joints by the European co-operators would take place on 1 April 1983. Where L-joints were exposed at this time, sampling after 8 months exposure is due on 1 December 1983. The present document draws attention to relevant previous documents which describe the sampling methods to be adopted. It also provides Tables for recording the results.
J K Carey, A F Bravery


The accelerated field simulator (= fungal cellar)
1982 - IRG/WP 2170
G C Johnson, J D Thornton, H Greaves


Surveillance médicale des personnels exposés aux produits de préservation du bois
1990 - IRG/WP 3588
J-C Aubrun


Preventive action against fungal decay: A comparative experiment on the effects of natural and artificial infection of wood by Basidiomycetes
1981 - IRG/WP 2160
M Fougerousse


Evaluation of new creosote formulations after extended exposures in fungal cellar tests and field plot tests
2000 - IRG/WP 00-30228
Although creosote, or coal tar creosote, has been the choice of preservative treatment for the railroad industry since the 1920s, exuding or "bleeding" on the surface of creosote-treated products has been one incentive for further enhancements in creosote production and utility (Crawford et al., 2000). To minimize this exuding problem, laboratories such as Koppers Industries Inc., USA, and Commonwealth Scientific and Industrial Research Organization (CSIRO), Division of Chemical and Wood Technology, Melbourne, Australia, have developed changes in processing of coal tar that produce distillates with fewer contaminants. This "clean distillate" is then used to formulate "clean creosote" as a preservative. These new, unique creosote formulations are being investigated as part of a program to enhance the use of regionally important wood species in the United States. Four retention levels of each of two new creosote formulations creosote, one pigment-emulsified creosote (PEC) and one creosote formulation that meets the AWPA Standard C2-95 for P1/P13 creosote (AWPA, 1995a), were applied to two softwood species and two hardwood species. Two laboratory procedures, the soil-block and fungal cellar tests (accelerated field simulator), were used to evaluate the four creosote formulations. These procedures characterized the effectiveness of the wood preservatives. The soil-block tests were used to determine the minimum threshold level of the preservative necessary to inhibit decay by pure cultures of decay fungi. In general, the soil block tests showed there was little difference in the ability of the four creosote formulations to prevent decay at the three highest retention levels as summarized in a previous report by Crawford and DeGroot (1996). The soil-block tests will not be discussed in this report. Fungal cellar tests expose treated wood to mixtures of soil-borne fungi that promote accelerated attack. Crawford and DeGroot (1996) discussed the evaluation of the creosote formulations after 17 months of exposure in the USDA Forest Service, Forest Products Laboratory (FPL), fungal cellar. At that point in time data from the fungal cellar tests showed that softwoods are protected better than hardwoods for all four formulations of creosote tested. This report will discuss exposure of the fungal cellar stakes upto 36 months. In addition, field stake tests are being used to verify service life of the new creosote formulations in vivo. Results from accelerated tests are indicative of field performance, but the correlation between laboratory and field results is still being investigated. Field stake tests are regarded as critical, long-term evaluations that provide results most directly related to the performance of treated products in service. In this study, we report on the performance of the creosote formulations after five years of exposure in field tests.
D M Crawford, P K Lebow, R C De Groot


Ultra-structural observations on the degradation of wood surfaces during weathering
1987 - IRG/WP 2280
Radiata pine (Pinus radiata D. Don) sapwood was converted into blocks with a transverse face about 5 mm square and measuring 8 mm longitudinally. Transverse (T.S.), Radial (R.L.S.) and Tangential (T.L.S.) surfaces were prepared and specimens exposed to the weather inclined at 45° facing equatorially for periods of between 20-60 days. After 30 days exposure erosion of the middle lamella was observed followed after 40 days exposure by extensive separation of individual fibres at the interface of the middle lamella and secondary wall. Degradation of the S2 layer of the cell wall revealed corrugations orientated parallel to the fibre axis suggesting preferential removal of cell wall components. Further degradation proceeded by progressive delamination and checking of the S2 and erosion of the S3 cell wall layer. In addition to the above changes preferential degradation of the rays was observed in radial (R.L.S.) and tangential (T.L.S.) longitudinal surfaces.
P D Evans, S Thein


In-ground performance of two formulations of chlorothalonil after five years of exposure at three test sites in Australia
1996 - IRG/WP 96-30101
Sapwood specimens of Pinus radiata D. Don and Eucalyptus regnans F. Muell. were each treated to three retentions of each of two preservative formulations (chlorothalonil in oil; chlorothalonil plus chlorpyrifos in oil) and installed in-ground at three field test sites in Australia. Specimens were treated with each formulation to achieve 3.2, 6.4 and 12.8 kg/m³ of chlorothalonil a.i. and 3.2 + 0.2, 6.4 + 0.4 and 12.8 + 0.8 kg/m³ of chlorothalonil plus chlorpyrifos a.i. For comparison, specimens of each timber species, treated to a commercial in-ground retention of a copper-chromium-arsenic (CCA) formulation, were also installed. Treated specimens (including controls) have been rated for their condition annually for attack by subterranean termites and fungal decay using a scale ranging from 4 (sound) down to 0 (failed). After five years of exposure, mean termite and decay scores for replicate test specimens at each site reveal that the performance of all three retentions of each formulation, particularly the two highest retentions, is comparable to CCA.
J W Creffield, T L Woods, N Chew


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