scholarly journals Effect of Concrete on the pH and Susceptibility of Treated Pine to Decay by Brown-Rot Fungi

Forests ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 41 ◽  
Author(s):  
Darrel Nicholas ◽  
Amy Rowlen ◽  
David Milsted

Treated wood timbers employed in ground contact are often installed with a cement collar to firmly fix the structural wood post in place. Few prior studies have determined the effect of concrete on decay efficacy on treated wood, however. Treated wood nominal 4 × 4 posts were installed at four locations, with the upper ground-contact portion of each post encased in concrete, and the samples removed at various times for pH measurements. The wood alkalinity quickly increased at all four sites for the portion of the treated wood in concrete contact compared to the wood in ground contact without concrete. In laboratory decay tests employing three decay fungi, untreated wood which was first exposed or unexposed to concrete had no consistent difference in decay susceptibility. For wood treated with three different commercial copper/organic systems, cement exposure had no effect on wood treated with an amine copper azole system, while treatment with amine copper quat showed a statistically significant fungal efficacy enhancement for cement-exposed samples with both copper-tolerant fungi. Conversely, with a micronized copper azole preservative, cement exposure resulted in reduced fungal efficacy compared to treated samples which were not cement-exposed for all three decay fungi.

Holzforschung ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Lukas Emmerich ◽  
Maja Bleckmann ◽  
Sarah Strohbusch ◽  
Christian Brischke ◽  
Susanne Bollmus ◽  
...  

Abstract Chemical wood modification has been used to modify wood and improve its decay resistance. However, the mode of protective action is still not fully understood. Occasionally, outdoor products made from chemically modified timber (CMT) show internal decay while their outer shell remains intact. Hence, it was hypothesized that wood decay fungi may grow through CMT without losing their capability to degrade non-modified wood. This study aimed at developing a laboratory test set-up to investigate (1) whether decay fungi grow through CMT and (2) retain their ability to degrade non-modified wood. Acetylated and 1,3-dimethylol-4,5-dihydroxyethyleneurea (DMDHEU) treated wood were used in decay tests with modified ‘mantle specimens’ and untreated ‘core dowels’. It became evident that white rot (Trametes versicolor), brown rot (Coniophora puteana) and soft rot fungi can grow through CMT without losing their ability to degrade untreated wood. Consequently, full volume impregnation of wood with the modifying agent is required to achieve complete protection of wooden products. In decay tests with DMDHEU treated specimens, significant amounts of apparently non-fixated DMDHEU were translocated from modified mantle specimens to untreated wood cores. A diffusion-driven transport of nitrogen and DMDHEU seemed to be responsible for mass translocation during decay testing.


2020 ◽  
Vol 11 ◽  
Author(s):  
Katie M. Ohno ◽  
Amy B. Bishell ◽  
Glen R. Stanosz

Copper tolerance of brown-rot basidiomycete decay fungi can lessen the efficacy of copper-containing wood preservatives for wood products in-service. The purpose of this study was to evaluate wood mass loss and differential expression of three genes that have putative annotations for copper-transporting ATPase pumps (FIBRA_00974, FIBRA_04716, and FIBRA_01430). Untreated southern pine (SP) and SP treated with three concentrations of ammoniacal copper citrate (CC, 0.6, 1.2, and 2.4%) were exposed to two copper-tolerant Fibroporia radiculosa isolates (FP-90848-T and L-9414-SP) and copper-sensitive Gloeophyllum trabeum isolate (MAD 617) in a 4-week-long standard decay test (AWPA E10-19). Decay of copper-treated wood was inhibited by G. trabeum (p = 0.001); however, there was no inhibition of decay with increasing copper concentrations by both F. radiculosa isolates. Initially, G. trabeum and one F. radiculosa isolate (L-9414-SP) highly upregulated FIBRA_00974 and FIBRA_04716 on copper-treated wood at week 1 (p = 0.005), but subsequent expression was either not detected or was similar to expression on untreated wood (p = 0.471). The other F. radiculosa isolate (FP-90848-T) downregulated FIBRA_00974 (p = 0.301) and FIBRA_04716 (p = 0.004) on copper-treated wood. FIBRA_01430 expression by G. trabeum was not detected, but was upregulated by both F. radiculosa FP-90848-T (p = 0.481) and L-9414-SP (p = 0.392). Results from this study suggest that all three test fungi utilized different mechanisms when decaying copper-treated wood. Additionally, results from this study do not provide support for the involvement of these putative gene annotations for copper-transporting ATPase pumps in the mechanism of copper-tolerance.


1983 ◽  
Vol 61 (1) ◽  
pp. 171-173 ◽  
Author(s):  
E. L. Schmidt ◽  
D. W. French

Successive collections of basidiospores, produced in culture from the same hymenial areas of four species of wood decay fungi, were tested for spore germination percentage on malt extract agar under controlled conditions. Spores from white rot fungi retained high germination levels after 5 weeks of spore production, but germination averages for brown rot fungi decreased by more than 50%. Such variation should be considered in wood pathology research using spore germination bioassay.


Polymers ◽  
2021 ◽  
Vol 13 (21) ◽  
pp. 3758
Author(s):  
Miloš Pánek ◽  
Vlastimil Borůvka ◽  
Jana Nábělková ◽  
Kristýna Šimůnková ◽  
Aleš Zeidler ◽  
...  

In the future, we can expect increased requirements to the health and ecological integrity of biocides used for the protection of wood against bio-attacks, and it is therefore necessary to search for and thoroughly test new active substances. Caffeine has been shown to have biocidal efficacy against wood-destroying fungi, moulds and insects. The aim of the research was to determine whether the effectiveness of caffeine, as a fungicide of natural origin, is affected by a different type of treated wood. Norway spruce mature wood (Picea abies), Scots pine sapwood (Pinus sylvestris), and European beech wood (Fagus sylvatica) were tested in this work. The samples were treated using long-term dipping technology or coating (according to EN 152:2012) and then tested against selected wood-destroying brown rot fungi according to the standard EN 839:2015, wood-staining fungi according to EN 152:2012, and against mould growth according to EN 15457:2015. The penetration of caffeine solution into wood depth was also evaluated using liquid extraction chromatography, as well as the effect of the treatment used on selected physical and mechanical properties of wood. The test results showed that the type of wood used and the specific type of wood-degrading agent had a significant effect on the effectiveness of caffeine protection. The most resistant wood was the treated spruce, whereas the most susceptible to deterioration was the treated white pine and beech wood. The results of the work showed that caffeine treatment is effective against wood-destroying fungi at a concentration of 2%, and at 1% in some of the tested cases. It can be used as an ecologically acceptable short-term protection alternative against wood-staining fungi in lumber warehouses and is also partially effective against moulds. It also does not have negative effects on changes in the physical and mechanical properties of the tested wood species.


Forests ◽  
2020 ◽  
Vol 11 (9) ◽  
pp. 907
Author(s):  
Magdalena Woźniak ◽  
Patrycja Kwaśniewska-Sip ◽  
Michał Krueger ◽  
Edward Roszyk ◽  
Izabela Ratajczak

The development of new bio-friendly alternatives for wood conservation is of great interest and necessary for environmental protection. In this paper, the preparations based on the propolis extract and silicon compounds were used as green wood preservatives. The wood was treated with 15% propolis extract (EEP) and two propolis-silane preparations, namely, EEP-VTMOS/TEOS (EEP with vinyltrimethoxysilane and tetraethyl orthosilicate) and EEP-MPTMOS/TEOS (EEP with 3-(trimethoxysilyl) propyl methacrylate and tetraethyl orthosilicate). The aim of the research was to determine the properties of treated wood, which was characterized by Fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance (NMR), atomic absorption spectroscopy (AAS), X-ray fluorescence (XRF), and scanning electron microscopy (SEM). Moreover, the resistance against brown-rot fungus Coniophora puteana and the mechanical properties of treated wood were also determined. The analysis of phenolic compounds concentration in treated wood indicated that phenols were in greater extent leached from wood treated with the propolis extract than from wood impregnated with the propolis-silane preparations. The presence of silicon in treated wood both before and after leaching was confirmed by CP MAS NMR measurements. In turn, AAS and XRF analyses indicated that the degree of Si leaching from wood impregnated with EEP-VTMOS/TEOS was approximately two times lower than from EEP-MPTMOS/TEOS treated wood. The results of chemical analyses confirmed that the constituents of the propolis-silane preparations formed permanent bonds with wood. In turn, the results of the antifungal efficacy against C. puteana showed that the propolis extract and the propolis-silane preparations limited the fungus activity, even the wood was subjected to leaching procedure. The treated wood showed an increase in bending strength and a decrease in the modulus of elasticity compared to untreated wood. The obtained results indicate that the propolis-silane preparations can be promising green wood preservatives, harmless for the natural environment.


2020 ◽  
Vol 70 (4) ◽  
pp. 469-475
Author(s):  
Katie M. Ohno ◽  
Amy B. Bishell ◽  
Glen R. Stanosz

Abstract Living organisms require copper for several cellular processes. Yet intracellular concentrations of copper must be regulated to avoid toxicity. Not much is known about mechanisms of copper regulation in wood decay fungi. However, one putative annotation for a copper homeostasis CutC gene (FIBRA_00129), found in other brown-rot wood decay fungi, has been annotated in Fibroporia radiculosa. The aim of this study was to evaluate wood mass loss and differential expression of FIBRA_00129 during initial decay of untreated and copper-treated wood by two copper-tolerant F. radiculosa isolates (FP-90848-T and L-9414-SP) compared with copper-sensitive Gloeophyllum trabeum. Untreated southern pine (Pinus spp.) and ammoniacal copper citrate treated southern pine at three concentrations (0.6%, 1.2%, and 2.4%) were used in a 4-week-long standard decay test. Results showed G. trabeum was unable to decay copper-treated wood while both F. radiculosa isolates successfully decayed southern pine at all copper concentrations. G. trabeum and F. radiculosa L-9414-SP showed no detectable FIBRA_00129 expression over the course of this study. F. radiculosa FP-90848-T showed greater FIBRA_00129 downregulation on copper-treated wood than on untreated wood (P = 0.003). Additionally, there was greater FIBRA_00129 downregulation in F. radiculosa FP-90848-T at week 3 compared with other weeks (P = 0.015). Future studies are needed to further evaluate FIBRA_00129 during the decay process to determine its potential role in copper-tolerance.


Holzforschung ◽  
2009 ◽  
Vol 63 (3) ◽  
Author(s):  
Pradeep Verma ◽  
Ulrich Junga ◽  
Holger Militz ◽  
Carsten Mai

AbstractThe resistance of beech and pine wood blocks treated with 1,3-dimethylol-4,5-dihydroxyethylene urea (DMDHEU) againstTrametes versicolorandConiophora puteanaincreased with increasing weight percent gain (WPG) of DMDHEU. Full protection [mass loss (ML) below 3%] was reached at WPGs of approximately 15% (beech) and 10% (pine). Untreated and DMDHEU treated blocks were infiltrated with nutrients and thiamine prior to fungal incubation and it was observed whether the destruction or removal of nutrients and vitamins during the modification process has an influence on the ML caused by the fungi. This study revealed that no considerable differences were found. Then, the cell wall integrity was partly destroyed by milling and the decay of the fine wood powder filled into steel mesh bags was compared to that of wood mini-blocks. The purpose of this study was to examine whether the effects of surface area, cell wall bulking, and reduction in micro-void diameters play a role in decay resistance. The ML caused by the fungi, however, also decreased with increasing WPG and showed comparable patterns similar to the case of mini-blocks. ML of powder bearing the highest WPG appeared to be caused by losses in DMDHEU during fungal incubation. For brown rotted wood, the infrared absorption ratios at 1030 cm-1and 1505 cm-1revealed decreasing decay of polysaccharides with increasing WPG of treated wood.


Holzforschung ◽  
2010 ◽  
Vol 64 (3) ◽  
Author(s):  
Cihat Tascioglu ◽  
Kunio Tsunoda

Abstract Vacuum-impregnation with copper azole was applied as a post-treatment to five commercially available wood-based composites with thicknesses of approximately 12 mm, such as softwood plywood (SWP), hardwood plywood (HWP), medium density fiberboard (MDF), oriented strand board (OSB), and particleboard (PB). Untreated and treated composites were tested for their resistance to decay fungi (brown rot fungus Fomitopsis palustris and white rot fungus Trametes versicolor) and the subterranean termite Coptotermes formosanus by Japanese standardized laboratory test methods. Untreated MDF was highly resistant to both biological attacks and seemed to require no preservative treatment under less hazardous conditions, i.e., under protected and above-ground applications, with possible occasional wetting. PB was ranked second, and needed further protection only against C. formosanus. Copper azole did not adequately protect SWP from F. palustris and termite. OSB was not protected either against F. palustris and T. versicolor even at a concentration level of 1 kg copper azole per m3 in contrary to blocks of Cryptomeria japonica sapwood, which was protected at these concentration levels. The biological resistance of HWP was reasonably improved by copper azole. The performance of wood-based composites treated with copper azole, which was inferior to the biological resistance of treated C. japonica sapwood blocks, might depend on the thickness or layer profile, density as a result of porosity, uneven distribution of the preservative in the composites, and the susceptibility of the component raw materials.


Holzforschung ◽  
1999 ◽  
Vol 53 (6) ◽  
pp. 563-568 ◽  
Author(s):  
Frederick Green ◽  
Carol A. Clausen

SummaryHydrolysis of bordered and pinoid pits may be a key event during colonization of wood by decay fungi. Although pits are numerous, studies of pectin-hydrolyzing enzymes in wood decay fungi are scarce, probably because of the relatively low content (less than 4 %) of pectin in wood and because of the primary focus on understanding the degradation of lignified components. Endopolygalacturonase (endo- PG) activity was estimated by cup-plate assay and viscosity reduction of pectin from liquid cultures of fifteen brown-rot and eight white-rot basidiomycetous fungi using sodium polypectate as the carbon source. Oxalic acid was estimated in liquid culture and related to mycelial weight of each fungus. Changes in longitudinal gas permeability of southern pine cores exposed to selected decay fungi in liquid culture were measured to determine the extent of hydrolysis of bordered pits. Twelve of fifteen brown-rot and six of eight white-rot fungi tested were positive for at least one of the polygalacturonase test methods. Accumulation of oxalic acid was detected in thirteen of fifteen brown-rot isolates and none of the white-rot fungi tested. Gas permeability of pine cores increased approximately fourfold among brown-rot fungi tested and eighteenfold among white-rot fungi tested. Scanning electron microscopy revealed bordered pit membrane hydrolysis in cores colonized by white-rot fungi, but only torus damage, weakening and tearing of the pit membranes, was observed in cores exposed to brown-rot fungi. We conclude that both brown- and white-rot decay fungi have the enzymatic capacity to hydrolyze pectin, damage bordered pit membranes, and increase wood permeability during colonization and incipient decay.


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