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• 1. [Article] Conserving energy by environmentally acceptable practices in maintaining and procuring transmission poles for long service ; August 1989

  Evaluations of previously established field trials indicate that chioropicrin, and Vorlex continue to provide protection to Douglas-fir poles, although the degree of protection is diminishing. Reapplication ...

  Citation × Citation Citation Abstract Copy Title: Conserving energy by environmentally acceptable practices in maintaining and procuring transmission poles for long service ; August 1989 Author: Morrell, Jeffrey J., Oregon State University. Dept. of Forest Products, Corden, M. E. (Malcolm E.) Evaluations of previously established field trials indicate that chioropicrin, and Vorlex continue to provide protection to Douglas-fir poles, although the degree of protection is diminishing. Reapplication of Vapam 18 years after the initial application eliminated fungi which had recolonized the poles. Methylisothiocyanate (MITC) continues to protect Douglas-fir poles 12 years after application. Gelatin encapsulation of MITC or chioropicrin appears to have no negative influence on fungitoxicity of these chemicals. Application of water to decompose the gelatin accelerated initial chemical release, but had no longterm effects on performance. A series of laboratory trials have been established to evaluate the performance of sodium n-methyldithiocarbamate (NaMDC), the active ingredient of Vapam. This chemical decomposes more slowly than the liquid formulations and a number of additives are being evaluated to accelerated decomposition. Along with the solid NaMDC, a pelletized formulation of Vapam was evaluated which contained 15 or 40 % NaMDC. These evaluations indicated that the addition of water accelerates release, but the fungal survival in these tests was more variable. The results suggest that a dosage 2 times greater than the liquid formulation is required for effective fungal control; however, further tests are planned to confirm these results. The evaluations of MITC-FUME in Douglas-fir and southern pine poles indicated that MITC has moved to a greater extent in Douglas-fir. Both closed tube bioassays and gas chromatographic analyses of ethyl acetate extracts of wood samples indicated that MITC was present at higher levels in Douglas-fir poles. Southern pine is far more permeable than Douglas-fir and MITC movement should be more rapid in this species. Further tests are planned to identify the nature of this delayed movement. 11 Evaluations of Dazomet, a crystalline solid which decomposes tO produce MITC in wood, indicate that detectable levels of this chemical are present in virtually all of the treatment groups. The decomposition rate of this chemical is normally too slow for effective fungal control and these trials are examining the ability of various additives to accelerate decomposition. Further evaluations of pole sections treated with Dazomet and selected additives are underway. A study to evaluate the effect of voids on fumigant effectivness suggests that voids do not adversely affect MITC movement through Douglas-fir pole sections. These results indicate that treatment of voids should be costeffective if the chemical is not applied directly to the void and if the pole retains a sufficient degree of strength. We continue to develop and refine a model for simulating the movement of MITC through Douglas-fir under varying temperature and moisture conditions. The model has been improved to permit three dimensional evaluations, but the times required for computation are still somewhat long. Further evaluations using a variety of environmental conditions are planned. Evaluations of potential replacements for pentachiorophenol for treatment of western redcedar sapwood and field drilled bolt holes have identified several promising alternatives. These chemicals are now under study in several modified field and laboratory tests. Field trials of several potential treatments for field drilled bolt holes indicate that Boracol 40, disodium octaborate tetrahydrate and ammonium bifluoride provided excellent protection over an 8 year period. These formulations all are relatively safe and can be easily applied in the field. 111 A laboratory trial to evaluate the effects of selected basidiomycetes on strength of Douglas-fir sapwood and heartwood has concluded. Fungal density, measured as the average number of fungi colonies per beam, gradually increased in all of the beams while longitudinal compression strength (LCS), modulus of rupture (MOR), and modulus of elesticity (MOE) slowly declined. Of the measurements, LCS appeared to be most useful, probably owing to the increased number of sampling sites per beam. The results indicate that the degree of colonization was not a good indicator of wood strength effects. The value of kerfing for decreasing post-treatment checking and improving the service life of Douglas-fir poles was evaluated using a series of inspection reports from a local utility. Kerfed transmission poles had substantially lower rates of internal decay and rejection, but there appeared to be little difference in the rate of decay between kerfed and non-kerfed distribution poles. The evaluation of disodium octaborate tetrahydrate for preventing colonization of air-seasoning Douglas-fir pole sections has been completed. Spraying with a 10 % boric acid equivalent solution (BAE) at 6 month intervals provided the greatest degree of protection, although dipping in a 20 % BAE solution at the start of air-seasoning produced a similar degree of protection. As expected, fungal colonization was far lower at the dryer Oroville site and borate treatment had little influence on the degree of fungal colonization at this site. The results indicate that borate treatment at the start of airseasoning is a viable method for limiting fungal colonization in moist airseasoning sites west of the Cascade Mountains. Evaluations of the tolerance of Stereum sanguinolentum and Peniophora spp. to elevated temperature exposures indicated that both of these fungi were extremely sensitive to elevated temperatures. The lack of long-term survival structures in these fungi probably accounts for this susceptibility to heat. iv A series of trials which measured internal temperatures in Douglas-fir pole sections during treatment with ammoniacal copper arsenate were used to develop a model for predicting internal heating during steaming. The results indicated that previous heating curves were overly optimistic in their prediction of heating. A series of heating curves for various pole diameters and starting conditions are presented. A number of externally applied groundline treatments are under evaluation in a field trial at Peavy Arboretum and a second trial will be established in the San Francisco Bay area. Seven formulations (including standards) are included. The Peavy site will be sampled in the next few months. The performance of copper naphthenate in western wood species is being evaluated in a series of small western redcedar sapwood stakelets which have been treated to a range of retentions and exposed in the fungus cellar. The results will be used to help confirm the performance of copper naphthenate in this species. Title: Conserving energy by environmentally acceptable practices in maintaining and procuring transmission poles for long service ; August 1989 Author: Morrell, Jeffrey J., Oregon State University. Dept. of Forest Products, Corden, M. E. (Malcolm E.) Evaluations of previously established field trials indicate that chioropicrin, and Vorlex continue to provide protection to Douglas-fir poles, although the degree of protection is diminishing. Reapplication of Vapam 18 years after the initial application eliminated fungi which had recolonized the poles. Methylisothiocyanate (MITC) continues to protect Douglas-fir poles 12 years after application. Gelatin encapsulation of MITC or chioropicrin appears to have no negative influence on fungitoxicity of these chemicals. Application of water to decompose the gelatin accelerated initial chemical release, but had no longterm effects on performance. A series of laboratory trials have been established to evaluate the performance of sodium n-methyldithiocarbamate (NaMDC), the active ingredient of Vapam. This chemical decomposes more slowly than the liquid formulations and a number of additives are being evaluated to accelerated decomposition. Along with the solid NaMDC, a pelletized formulation of Vapam was evaluated which contained 15 or 40 % NaMDC. These evaluations indicated that the addition of water accelerates release, but the fungal survival in these tests was more variable. The results suggest that a dosage 2 times greater than the liquid formulation is required for effective fungal control; however, further tests are planned to confirm these results. The evaluations of MITC-FUME in Douglas-fir and southern pine poles indicated that MITC has moved to a greater extent in Douglas-fir. Both closed tube bioassays and gas chromatographic analyses of ethyl acetate extracts of wood samples indicated that MITC was present at higher levels in Douglas-fir poles. Southern pine is far more permeable than Douglas-fir and MITC movement should be more rapid in this species. Further tests are planned to identify the nature of this delayed movement. 11 Evaluations of Dazomet, a crystalline solid which decomposes tO produce MITC in wood, indicate that detectable levels of this chemical are present in virtually all of the treatment groups. The decomposition rate of this chemical is normally too slow for effective fungal control and these trials are examining the ability of various additives to accelerate decomposition. Further evaluations of pole sections treated with Dazomet and selected additives are underway. A study to evaluate the effect of voids on fumigant effectivness suggests that voids do not adversely affect MITC movement through Douglas-fir pole sections. These results indicate that treatment of voids should be costeffective if the chemical is not applied directly to the void and if the pole retains a sufficient degree of strength. We continue to develop and refine a model for simulating the movement of MITC through Douglas-fir under varying temperature and moisture conditions. The model has been improved to permit three dimensional evaluations, but the times required for computation are still somewhat long. Further evaluations using a variety of environmental conditions are planned. Evaluations of potential replacements for pentachiorophenol for treatment of western redcedar sapwood and field drilled bolt holes have identified several promising alternatives. These chemicals are now under study in several modified field and laboratory tests. Field trials of several potential treatments for field drilled bolt holes indicate that Boracol 40, disodium octaborate tetrahydrate and ammonium bifluoride provided excellent protection over an 8 year period. These formulations all are relatively safe and can be easily applied in the field. 111 A laboratory trial to evaluate the effects of selected basidiomycetes on strength of Douglas-fir sapwood and heartwood has concluded. Fungal density, measured as the average number of fungi colonies per beam, gradually increased in all of the beams while longitudinal compression strength (LCS), modulus of rupture (MOR), and modulus of elesticity (MOE) slowly declined. Of the measurements, LCS appeared to be most useful, probably owing to the increased number of sampling sites per beam. The results indicate that the degree of colonization was not a good indicator of wood strength effects. The value of kerfing for decreasing post-treatment checking and improving the service life of Douglas-fir poles was evaluated using a series of inspection reports from a local utility. Kerfed transmission poles had substantially lower rates of internal decay and rejection, but there appeared to be little difference in the rate of decay between kerfed and non-kerfed distribution poles. The evaluation of disodium octaborate tetrahydrate for preventing colonization of air-seasoning Douglas-fir pole sections has been completed. Spraying with a 10 % boric acid equivalent solution (BAE) at 6 month intervals provided the greatest degree of protection, although dipping in a 20 % BAE solution at the start of air-seasoning produced a similar degree of protection. As expected, fungal colonization was far lower at the dryer Oroville site and borate treatment had little influence on the degree of fungal colonization at this site. The results indicate that borate treatment at the start of airseasoning is a viable method for limiting fungal colonization in moist airseasoning sites west of the Cascade Mountains. Evaluations of the tolerance of Stereum sanguinolentum and Peniophora spp. to elevated temperature exposures indicated that both of these fungi were extremely sensitive to elevated temperatures. The lack of long-term survival structures in these fungi probably accounts for this susceptibility to heat. iv A series of trials which measured internal temperatures in Douglas-fir pole sections during treatment with ammoniacal copper arsenate were used to develop a model for predicting internal heating during steaming. The results indicated that previous heating curves were overly optimistic in their prediction of heating. A series of heating curves for various pole diameters and starting conditions are presented. A number of externally applied groundline treatments are under evaluation in a field trial at Peavy Arboretum and a second trial will be established in the San Francisco Bay area. Seven formulations (including standards) are included. The Peavy site will be sampled in the next few months. The performance of copper naphthenate in western wood species is being evaluated in a series of small western redcedar sapwood stakelets which have been treated to a range of retentions and exposed in the fungus cellar. The results will be used to help confirm the performance of copper naphthenate in this species. Close

• 2. [Article] Conserving energy by environmentally acceptable practices in maintaining and procuring transmission poles for long service ; August 1990

  Evaluations of previously established field trials indicate that chioropicrin, and Vorlex continue to provide protection to Douglas-fir poles, although the degree of protection is diminishing. Reapplication ...

  Citation × Citation Citation Abstract Copy Title: Conserving energy by environmentally acceptable practices in maintaining and procuring transmission poles for long service ; August 1990 Author: Morrell, Jeffrey J., Oregon State University. Dept. of Forest Products, Corden, M. E. (Malcolm E.) Evaluations of previously established field trials indicate that chioropicrin, and Vorlex continue to provide protection to Douglas-fir poles, although the degree of protection is diminishing. Reapplication of Vapam 18 years after the initial application eliminated fungi which had recolonized the poles. Methylisothiocyanate (MITC) continues to protect Douglas-fir poles 12 years after application. Gelatin encapsulation of MITC or chioropicrin appears to have no negative influence on fungitoxicity of these chemicals. Application of water to decompose the gelatin accelerated initial chemical release, but had no longterm effects on performance. A series of laboratory trials have been established to evaluate the performance of sodium n-methyldithiocarbamate (NaMDC), the active ingredient of Vapam. This chemical decomposes more slowly than the liquid formulations and a number of additives are being evaluated to accelerated decomposition. Along with the solid NaMDC, a pelletized formulation of Vapam was evaluated which contained 15 or 40 % NaMDC. These evaluations indicated that the addition of water accelerates release, but the fungal survival in these tests was more variable. The results suggest that a dosage 2 times greater than the liquid formulation is required for effective fungal control; however, further tests are planned to confirm these results. The evaluations of MITC-FUME in Douglas-fir and southern pine poles indicated that MITC has moved to a greater extent in Douglas-fir. Both closed tube bioassays and gas chromatographic analyses of ethyl acetate extracts of wood samples indicated that MITC was present at higher levels in Douglas-fir poles. Southern pine is far more permeable than Douglas-fir and MITC movement should be more rapid in this species. Further tests are planned to identify the nature of this delayed movement. 11 Evaluations of Dazomet, a crystalline solid which decomposes tO produce MITC in wood, indicate that detectable levels of this chemical are present in virtually all of the treatment groups. The decomposition rate of this chemical is normally too slow for effective fungal control and these trials are examining the ability of various additives to accelerate decomposition. Further evaluations of pole sections treated with Dazomet and selected additives are underway. A study to evaluate the effect of voids on fumigant effectivness suggests that voids do not adversely affect MITC movement through Douglas-fir pole sections. These results indicate that treatment of voids should be costeffective if the chemical is not applied directly to the void and if the pole retains a sufficient degree of strength. We continue to develop and refine a model for simulating the movement of MITC through Douglas-fir under varying temperature and moisture conditions. The model has been improved to permit three dimensional evaluations, but the times required for computation are still somewhat long. Further evaluations using a variety of environmental conditions are planned. Evaluations of potential replacements for pentachiorophenol for treatment of western redcedar sapwood and field drilled bolt holes have identified several promising alternatives. These chemicals are now under study in several modified field and laboratory tests. Field trials of several potential treatments for field drilled bolt holes indicate that Boracol 40, disodium octaborate tetrahydrate and ammonium bifluoride provided excellent protection over an 8 year period. These formulations all are relatively safe and can be easily applied in the field. 111 A laboratory trial to evaluate the effects of selected basidiomycetes on strength of Douglas-fir sapwood and heartwood has concluded. Fungal density, measured as the average number of fungi colonies per beam, gradually increased in all of the beams while longitudinal compression strength (LCS), modulus of rupture (MOR), and modulus of elesticity (MOE) slowly declined. Of the measurements, LCS appeared to be most useful, probably owing to the increased number of sampling sites per beam. The results indicate that the degree of colonization was not a good indicator of wood strength effects. The value of kerfing for decreasing post-treatment checking and improving the service life of Douglas-fir poles was evaluated using a series of inspection reports from a local utility. Kerfed transmission poles had substantially lower rates of internal decay and rejection, but there appeared to be little difference in the rate of decay between kerfed and non-kerfed distribution poles. The evaluation of disodium octaborate tetrahydrate for preventing colonization of air-seasoning Douglas-fir pole sections has been completed. Spraying with a 10 % boric acid equivalent solution (BAE) at 6 month intervals provided the greatest degree of protection, although dipping in a 20 % BAE solution at the start of air-seasoning produced a similar degree of protection. As expected, fungal colonization was far lower at the dryer Oroville site and borate treatment had little influence on the degree of fungal colonization at this site. The results indicate that borate treatment at the start of airseasoning is a viable method for limiting fungal colonization in moist airseasoning sites west of the Cascade Mountains. Evaluations of the tolerance of Stereum sanguinolentum and Peniophora spp. to elevated temperature exposures indicated that both of these fungi were extremely sensitive to elevated temperatures. The lack of long-term survival structures in these fungi probably accounts for this susceptibility to heat. iv A series of trials which measured internal temperatures in Douglas-fir pole sections during treatment with ammoniacal copper arsenate were used to develop a model for predicting internal heating during steaming. The results indicated that previous heating curves were overly optimistic in their prediction of heating. A series of heating curves for various pole diameters and starting conditions are presented. A number of externally applied groundline treatments are under evaluation in a field trial at Peavy Arboretum and a second trial will be established in the San Francisco Bay area. Seven formulations (including standards) are included. The Peavy site will be sampled in the next few months. The performance of copper naphthenate in western wood species is being evaluated in a series of small western redcedar sapwood stakelets which have been treated to a range of retentions and exposed in the fungus cellar. The results will be used to help confirm the performance of copper naphthenate in this species. Title: Conserving energy by environmentally acceptable practices in maintaining and procuring transmission poles for long service ; August 1990 Author: Morrell, Jeffrey J., Oregon State University. Dept. of Forest Products, Corden, M. E. (Malcolm E.) Evaluations of previously established field trials indicate that chioropicrin, and Vorlex continue to provide protection to Douglas-fir poles, although the degree of protection is diminishing. Reapplication of Vapam 18 years after the initial application eliminated fungi which had recolonized the poles. Methylisothiocyanate (MITC) continues to protect Douglas-fir poles 12 years after application. Gelatin encapsulation of MITC or chioropicrin appears to have no negative influence on fungitoxicity of these chemicals. Application of water to decompose the gelatin accelerated initial chemical release, but had no longterm effects on performance. A series of laboratory trials have been established to evaluate the performance of sodium n-methyldithiocarbamate (NaMDC), the active ingredient of Vapam. This chemical decomposes more slowly than the liquid formulations and a number of additives are being evaluated to accelerated decomposition. Along with the solid NaMDC, a pelletized formulation of Vapam was evaluated which contained 15 or 40 % NaMDC. These evaluations indicated that the addition of water accelerates release, but the fungal survival in these tests was more variable. The results suggest that a dosage 2 times greater than the liquid formulation is required for effective fungal control; however, further tests are planned to confirm these results. The evaluations of MITC-FUME in Douglas-fir and southern pine poles indicated that MITC has moved to a greater extent in Douglas-fir. Both closed tube bioassays and gas chromatographic analyses of ethyl acetate extracts of wood samples indicated that MITC was present at higher levels in Douglas-fir poles. Southern pine is far more permeable than Douglas-fir and MITC movement should be more rapid in this species. Further tests are planned to identify the nature of this delayed movement. 11 Evaluations of Dazomet, a crystalline solid which decomposes tO produce MITC in wood, indicate that detectable levels of this chemical are present in virtually all of the treatment groups. The decomposition rate of this chemical is normally too slow for effective fungal control and these trials are examining the ability of various additives to accelerate decomposition. Further evaluations of pole sections treated with Dazomet and selected additives are underway. A study to evaluate the effect of voids on fumigant effectivness suggests that voids do not adversely affect MITC movement through Douglas-fir pole sections. These results indicate that treatment of voids should be costeffective if the chemical is not applied directly to the void and if the pole retains a sufficient degree of strength. We continue to develop and refine a model for simulating the movement of MITC through Douglas-fir under varying temperature and moisture conditions. The model has been improved to permit three dimensional evaluations, but the times required for computation are still somewhat long. Further evaluations using a variety of environmental conditions are planned. Evaluations of potential replacements for pentachiorophenol for treatment of western redcedar sapwood and field drilled bolt holes have identified several promising alternatives. These chemicals are now under study in several modified field and laboratory tests. Field trials of several potential treatments for field drilled bolt holes indicate that Boracol 40, disodium octaborate tetrahydrate and ammonium bifluoride provided excellent protection over an 8 year period. These formulations all are relatively safe and can be easily applied in the field. 111 A laboratory trial to evaluate the effects of selected basidiomycetes on strength of Douglas-fir sapwood and heartwood has concluded. Fungal density, measured as the average number of fungi colonies per beam, gradually increased in all of the beams while longitudinal compression strength (LCS), modulus of rupture (MOR), and modulus of elesticity (MOE) slowly declined. Of the measurements, LCS appeared to be most useful, probably owing to the increased number of sampling sites per beam. The results indicate that the degree of colonization was not a good indicator of wood strength effects. The value of kerfing for decreasing post-treatment checking and improving the service life of Douglas-fir poles was evaluated using a series of inspection reports from a local utility. Kerfed transmission poles had substantially lower rates of internal decay and rejection, but there appeared to be little difference in the rate of decay between kerfed and non-kerfed distribution poles. The evaluation of disodium octaborate tetrahydrate for preventing colonization of air-seasoning Douglas-fir pole sections has been completed. Spraying with a 10 % boric acid equivalent solution (BAE) at 6 month intervals provided the greatest degree of protection, although dipping in a 20 % BAE solution at the start of air-seasoning produced a similar degree of protection. As expected, fungal colonization was far lower at the dryer Oroville site and borate treatment had little influence on the degree of fungal colonization at this site. The results indicate that borate treatment at the start of airseasoning is a viable method for limiting fungal colonization in moist airseasoning sites west of the Cascade Mountains. Evaluations of the tolerance of Stereum sanguinolentum and Peniophora spp. to elevated temperature exposures indicated that both of these fungi were extremely sensitive to elevated temperatures. The lack of long-term survival structures in these fungi probably accounts for this susceptibility to heat. iv A series of trials which measured internal temperatures in Douglas-fir pole sections during treatment with ammoniacal copper arsenate were used to develop a model for predicting internal heating during steaming. The results indicated that previous heating curves were overly optimistic in their prediction of heating. A series of heating curves for various pole diameters and starting conditions are presented. A number of externally applied groundline treatments are under evaluation in a field trial at Peavy Arboretum and a second trial will be established in the San Francisco Bay area. Seven formulations (including standards) are included. The Peavy site will be sampled in the next few months. The performance of copper naphthenate in western wood species is being evaluated in a series of small western redcedar sapwood stakelets which have been treated to a range of retentions and exposed in the fungus cellar. The results will be used to help confirm the performance of copper naphthenate in this species. Close

• 3. [Article] Conserving energy by safe and environmentally acceptable practices in maintaining and procuring transmission poles ; August 1984

  Improved Fumigants After 14 years, chloropicrin, Vapam and Vorlex continue to effectively control internal decay of pressure-treated Douglas-fir transmission poles, but 6 years after application of methylisothiocyanate (MIT) ...

  Citation × Citation Citation Abstract Copy Title: Conserving energy by safe and environmentally acceptable practices in maintaining and procuring transmission poles ; August 1984 Author: Oregon State University, Oregon State University. Dept. of Forest Products Improved Fumigants After 14 years, chloropicrin, Vapam and Vorlex continue to effectively control internal decay of pressure-treated Douglas-fir transmission poles, but 6 years after application of methylisothiocyanate (MIT) some poles are becoming reinfested by decay fungi although NIT residues remain high in these poles. The closed-tube bioassay, developed through our research, is an effective method for detecting fumigant persistance, and future studies will aim at determining the actual fumigant concentrations detected in wood by this bioassay. A study of MIT movement through Douglas-fir pole sections following treatment with gelatin encapsulated MIT was completed and results indicate that addition of small quantities of water along with the capsules will give excellent fumigant release and movement into the wood. Decay fungi were virtually eliminated from in service transmission poles 21 months after treatment with gelatin encapsulated MIT near the groundline. In poles treated up to 12 feet above the groundline with encapsulated MIT and chloropicrin, no decay fungi could be isolated 1 year after treatment. Both fumigants were well distributed through the poles and appear to have moved laterally from the treatment holes. One of the goals of our research has been eventual fumigant application to poles at the treatment plant shortly after conventional preservative treatments. This would provide predrilled holes for later fumigant retreatment and would effectively protect the entire i iipole cross section. While the most economical application method would involve incorporating the fumigant treatment holes into the conventional predrilling process, it would also result in preservative treated fumigant holes. Consequently we have initiated studies to determine the influence of creosote and pentachlorophenol on fumigant movement into treated wood. Preliminary results indicate that creosote and P-9 penta base oil slow movement of MIT into wood but do not prevent the build up of fungitoxic concentrations in the wood. The new, pelletized MIT formulation has been evaluated in our laboratory assay for wood fumigants. The results indicate that pelletized MIT is as effective as pure MIT on an active ingredient basis. Since pelletized MIT has many similar application and safety advantages as encapsulated MIT, we intend to further evaluate pellets in poles in service. Cedar Sapwood Decay Control The effectiveness of seventeen chemicals (3 oil-borne, 14 water-borne) for controlling above-ground decay of cedar sapwood was evaluated using a modified soil block test and an Aspergillus bioassay. Pentachlorophenol (10%) in diesel oil, currently used for protecting cedar poles, was markedly superior to all other chemicals evaluated probably because of the increased penetrability of the oil, since penta in water at the same strength did not perform as well. Three other formulations, copper-8-quinolinolate (oil), pentachlorophenol (2% in water), and 3-iodo propynyl butyl carbamate (2% in water), exhibited some residual effectiveness; however, more time is necessary to determine if these chemicals will remain effective. An additional five chemicals will be evaluated this coming spring. iii The persistence of chloropicrin 5 years after treatment in western redcedar was also evaluated using open tube bioassays, closetube bioassays and gas chromatographic determinations. The open tube bioassay indicated that chioropicrin still effectively limited growth of the assay fungus, P. placenta. Similarly, closed tube bioassays indicated strong inhibition in the pole interior and lower inhibitions near the surface. Extraction/gas chromatographic procedures detected chloropicrin in all cores examined with the highest concentrations towards the pole interior. Chioropicrin concentration did not correlate with closed tube results, suggesting that these tests are measuring different fumigant properties. The results indicate that chloropicrin should be an effective treatment for preventing cedarbutt rot and may provide some protection to pole sapwood. Bolt Holes Control poles for the bolt hole protection study were again sampled and insufficient decay was found in these poles to warrant evaluation of the various decay prevention treatments. We will reevaluate the control poles this summer. Detecting decay and estimating residual strength in poles An infrared spectrophotometric method of analyzing warm water extracts of decayed and non-decay wood was evaluated with a number of brown and white rot fungi. Brown rot was highly correlated with absorption peaks produced at wavelength 17201cm. Work is now underway to identify this peak to determine if less involved detection methods might be employed. iv Fluorescent labeled lectins, which have high specificity for selected carbohydrates, were also evaluated as potential fungal indicators. Of the lectins tested, wheat germ agglutinin appears the most promising since it strongly reacted with chitin in the fungal cell wall, making decay hyphae visible at very early stages of decay. Evaluation of Douglas-fir beams air-seasoned for 1 or 2 years using Pilodyn pin penetration, longitudinal compression, radial compression, bending and culturing indicated that, while there is a well established fungal flora in the wood, this flora has not yet affected strength. These tests will be performed on the 3 year airseasoned beams this coming year. Of the strength tests employed, longitudinal compression appears promising for estimating pole bending strength and we intend to further evaluate this method. As a second phase of this evaluation, the effect of moisture content on Pilodyn pin penetration was examined. This information is necessary since pin penetration varies with moisture content and must be corrected to compare values from different poles. Pin penetration increased with increasing moisture content up to fiber saturation and stabilized above this point. The moisture content at 0.5 inches was highly correlated with pin penetration, and this depth might be a convenient standard measuring point. En a new phase of the project, preliminary acoustic testing was begun using small beams from poles at varying stages of decay. These beams were sonically evaluated and then loaded to failure in three point bending tests. Sonic evaluation was highly correlated with NOR; however, much more testing will be necessary before such an apparatus can be applied to posts or poles. V Initiation of decay in Douglas-fir poles prior to pressure treatment The ability of basidiomycetes isolated from air-seasoning poles to reduce wood strength was evaluated in rapid tests for toughness by impact bending and changes in the breaking radius of Douglas-fir test wafers. Although some fungi behaved differently in the two tests, the test correlations were relatively high (r2 = O.78S). Of 26 basidiomycetous species evaluated, Poria placenta, P. carbonica, P. xantha and Crustoderma dryinum most rapidly decayed Douglas-fir heartwood, but at least one isolate of most of the other species tested significantly reduced toughness. While the wood decaying ability of each fungus is important, the frequency of isolation also must be considered when determining the overall importance of a species. To determine the influence of wood temperature and moisture content on establishment of P. carbonica in Douglas-fir heartwood, a method was developed for direct observation of germinating spores on wood. In this test, chiamydospores and basidiospores failed to germinate or colonize wood at moisture content below fiber saturation suggesting that free water is necessary for infection. Chiamydospores germinated most readily and colonized wood at 22°C, while germination was significantly lower and the fungus failed to become established in wood at 5 or 35°C. Similar temperature responses were obtained with basidiospores although these spores failed to germinate at 5 and 35°C. Nevertheless, basidiospores may remain viable and retain the potential to establish colonies once conditions become more favorable. vi Exposure of sterilized pole sections at four Pacific Northwest air-seasoning sites for successive 3-month periods showed a significant increase in basidiomycete isolation frequency for the period Nov. '81-Jan.'82. Furthermore, the frequency increased from the northern to the southern most site. Detailed study of the site weather patterns strongly suggests that increased basidiomycetous infection can be related to number of days with measurable rain fall and temperatures conducive to fungal growth. During the other periods studied, temperature or precipitation conditions were unfavorable for infection and pole section moisture contents fell below fiber saturation. This in turn limited spore germination and fungal colonization of the wood. About 30 different basidiomycetous species have been identified from isolates cultured from sterilized pole sections exposed at the four sites. In general, the species were the same as those isolated form air-seasoning poles although there were some significant differences between the species obtained from the different sites. The frequency of P. placenta mono- and dikaryons was particularly high with monokaryons more abundant at three of the four locations. Individual species exhibited distinct colonization patterns from different pole zones. For example, P. placenta was isolated most frequently from heartwood exposed at the pole ends while Peniophora spp. and llaemotostereum sanguinolentum were recovered most frequently from the upper surfaces of the pole sections. vii Preventing infection of poles by decay fungi during air-seasoning Pole sections treated with ammonium bifluoride (NH4HF2) or gelatin encapsulated MIT and chioropicrin were extensively sampled after air seasoning to determine the influence of these chemicals on wood colonization by decay fungi. Preliminary results indicate that after 2 years NH4HF2 and the fumigants significantly reduced basidiomycetous colonization of sterile wood. Surface Decay Poles treated with Vapam 14 years ago were extensively cored, the cores were cultured and the resulting fungi were identified to evaluate the fungal flora of fumigant treated wood. A well developed fungal flora was identified that differed from that found in nonfumigant treated wood. These fungi will be further evaluated to determine their role in fumigant effectiveness. Title: Conserving energy by safe and environmentally acceptable practices in maintaining and procuring transmission poles ; August 1984 Author: Oregon State University, Oregon State University. Dept. of Forest Products Improved Fumigants After 14 years, chloropicrin, Vapam and Vorlex continue to effectively control internal decay of pressure-treated Douglas-fir transmission poles, but 6 years after application of methylisothiocyanate (MIT) some poles are becoming reinfested by decay fungi although NIT residues remain high in these poles. The closed-tube bioassay, developed through our research, is an effective method for detecting fumigant persistance, and future studies will aim at determining the actual fumigant concentrations detected in wood by this bioassay. A study of MIT movement through Douglas-fir pole sections following treatment with gelatin encapsulated MIT was completed and results indicate that addition of small quantities of water along with the capsules will give excellent fumigant release and movement into the wood. Decay fungi were virtually eliminated from in service transmission poles 21 months after treatment with gelatin encapsulated MIT near the groundline. In poles treated up to 12 feet above the groundline with encapsulated MIT and chloropicrin, no decay fungi could be isolated 1 year after treatment. Both fumigants were well distributed through the poles and appear to have moved laterally from the treatment holes. One of the goals of our research has been eventual fumigant application to poles at the treatment plant shortly after conventional preservative treatments. This would provide predrilled holes for later fumigant retreatment and would effectively protect the entire i iipole cross section. While the most economical application method would involve incorporating the fumigant treatment holes into the conventional predrilling process, it would also result in preservative treated fumigant holes. Consequently we have initiated studies to determine the influence of creosote and pentachlorophenol on fumigant movement into treated wood. Preliminary results indicate that creosote and P-9 penta base oil slow movement of MIT into wood but do not prevent the build up of fungitoxic concentrations in the wood. The new, pelletized MIT formulation has been evaluated in our laboratory assay for wood fumigants. The results indicate that pelletized MIT is as effective as pure MIT on an active ingredient basis. Since pelletized MIT has many similar application and safety advantages as encapsulated MIT, we intend to further evaluate pellets in poles in service. Cedar Sapwood Decay Control The effectiveness of seventeen chemicals (3 oil-borne, 14 water-borne) for controlling above-ground decay of cedar sapwood was evaluated using a modified soil block test and an Aspergillus bioassay. Pentachlorophenol (10%) in diesel oil, currently used for protecting cedar poles, was markedly superior to all other chemicals evaluated probably because of the increased penetrability of the oil, since penta in water at the same strength did not perform as well. Three other formulations, copper-8-quinolinolate (oil), pentachlorophenol (2% in water), and 3-iodo propynyl butyl carbamate (2% in water), exhibited some residual effectiveness; however, more time is necessary to determine if these chemicals will remain effective. An additional five chemicals will be evaluated this coming spring. iii The persistence of chloropicrin 5 years after treatment in western redcedar was also evaluated using open tube bioassays, closetube bioassays and gas chromatographic determinations. The open tube bioassay indicated that chioropicrin still effectively limited growth of the assay fungus, P. placenta. Similarly, closed tube bioassays indicated strong inhibition in the pole interior and lower inhibitions near the surface. Extraction/gas chromatographic procedures detected chloropicrin in all cores examined with the highest concentrations towards the pole interior. Chioropicrin concentration did not correlate with closed tube results, suggesting that these tests are measuring different fumigant properties. The results indicate that chloropicrin should be an effective treatment for preventing cedarbutt rot and may provide some protection to pole sapwood. Bolt Holes Control poles for the bolt hole protection study were again sampled and insufficient decay was found in these poles to warrant evaluation of the various decay prevention treatments. We will reevaluate the control poles this summer. Detecting decay and estimating residual strength in poles An infrared spectrophotometric method of analyzing warm water extracts of decayed and non-decay wood was evaluated with a number of brown and white rot fungi. Brown rot was highly correlated with absorption peaks produced at wavelength 17201cm. Work is now underway to identify this peak to determine if less involved detection methods might be employed. iv Fluorescent labeled lectins, which have high specificity for selected carbohydrates, were also evaluated as potential fungal indicators. Of the lectins tested, wheat germ agglutinin appears the most promising since it strongly reacted with chitin in the fungal cell wall, making decay hyphae visible at very early stages of decay. Evaluation of Douglas-fir beams air-seasoned for 1 or 2 years using Pilodyn pin penetration, longitudinal compression, radial compression, bending and culturing indicated that, while there is a well established fungal flora in the wood, this flora has not yet affected strength. These tests will be performed on the 3 year airseasoned beams this coming year. Of the strength tests employed, longitudinal compression appears promising for estimating pole bending strength and we intend to further evaluate this method. As a second phase of this evaluation, the effect of moisture content on Pilodyn pin penetration was examined. This information is necessary since pin penetration varies with moisture content and must be corrected to compare values from different poles. Pin penetration increased with increasing moisture content up to fiber saturation and stabilized above this point. The moisture content at 0.5 inches was highly correlated with pin penetration, and this depth might be a convenient standard measuring point. En a new phase of the project, preliminary acoustic testing was begun using small beams from poles at varying stages of decay. These beams were sonically evaluated and then loaded to failure in three point bending tests. Sonic evaluation was highly correlated with NOR; however, much more testing will be necessary before such an apparatus can be applied to posts or poles. V Initiation of decay in Douglas-fir poles prior to pressure treatment The ability of basidiomycetes isolated from air-seasoning poles to reduce wood strength was evaluated in rapid tests for toughness by impact bending and changes in the breaking radius of Douglas-fir test wafers. Although some fungi behaved differently in the two tests, the test correlations were relatively high (r2 = O.78S). Of 26 basidiomycetous species evaluated, Poria placenta, P. carbonica, P. xantha and Crustoderma dryinum most rapidly decayed Douglas-fir heartwood, but at least one isolate of most of the other species tested significantly reduced toughness. While the wood decaying ability of each fungus is important, the frequency of isolation also must be considered when determining the overall importance of a species. To determine the influence of wood temperature and moisture content on establishment of P. carbonica in Douglas-fir heartwood, a method was developed for direct observation of germinating spores on wood. In this test, chiamydospores and basidiospores failed to germinate or colonize wood at moisture content below fiber saturation suggesting that free water is necessary for infection. Chiamydospores germinated most readily and colonized wood at 22°C, while germination was significantly lower and the fungus failed to become established in wood at 5 or 35°C. Similar temperature responses were obtained with basidiospores although these spores failed to germinate at 5 and 35°C. Nevertheless, basidiospores may remain viable and retain the potential to establish colonies once conditions become more favorable. vi Exposure of sterilized pole sections at four Pacific Northwest air-seasoning sites for successive 3-month periods showed a significant increase in basidiomycete isolation frequency for the period Nov. '81-Jan.'82. Furthermore, the frequency increased from the northern to the southern most site. Detailed study of the site weather patterns strongly suggests that increased basidiomycetous infection can be related to number of days with measurable rain fall and temperatures conducive to fungal growth. During the other periods studied, temperature or precipitation conditions were unfavorable for infection and pole section moisture contents fell below fiber saturation. This in turn limited spore germination and fungal colonization of the wood. About 30 different basidiomycetous species have been identified from isolates cultured from sterilized pole sections exposed at the four sites. In general, the species were the same as those isolated form air-seasoning poles although there were some significant differences between the species obtained from the different sites. The frequency of P. placenta mono- and dikaryons was particularly high with monokaryons more abundant at three of the four locations. Individual species exhibited distinct colonization patterns from different pole zones. For example, P. placenta was isolated most frequently from heartwood exposed at the pole ends while Peniophora spp. and llaemotostereum sanguinolentum were recovered most frequently from the upper surfaces of the pole sections. vii Preventing infection of poles by decay fungi during air-seasoning Pole sections treated with ammonium bifluoride (NH4HF2) or gelatin encapsulated MIT and chioropicrin were extensively sampled after air seasoning to determine the influence of these chemicals on wood colonization by decay fungi. Preliminary results indicate that after 2 years NH4HF2 and the fumigants significantly reduced basidiomycetous colonization of sterile wood. Surface Decay Poles treated with Vapam 14 years ago were extensively cored, the cores were cultured and the resulting fungi were identified to evaluate the fungal flora of fumigant treated wood. A well developed fungal flora was identified that differed from that found in nonfumigant treated wood. These fungi will be further evaluated to determine their role in fumigant effectiveness. Close

• 4. [Article] Conserving energy by environmentally acceptable practices in maintaining and procuring transmission poles for long service ; August 1992

  Evaluation of previously established field trials of remedial internal treatments demonstrates the continued performance of chioropicrin, Vorlex, and methylisothiocyanate (MITC). While the degree of protection ...

  Citation × Citation Citation Abstract Copy Title: Conserving energy by environmentally acceptable practices in maintaining and procuring transmission poles for long service ; August 1992 Author: Morrell, Jeffrey J., Oregon State University. Dept. of Forest Products, Corden, M. E. (Malcolm E.) Evaluation of previously established field trials of remedial internal treatments demonstrates the continued performance of chioropicrin, Vorlex, and methylisothiocyanate (MITC). While the degree of protection afforded by these treatments has declined with time, residual fungitoxic levels remain in many tests. Field trials of gelatin encapsulated MITC indicate that gelatin had no negative effect on fumigant performance even when no water was added at the time of treatment. Closed tube bioassays, chemical analyses, and culturing of Douglas-fir and southern pine poles treated with glass encapsulated METC (MITC-Fume) indicate that this chemical is outperforming metham sodium 3 years after application. While the glass vials lost chemical very slowly, the slow release rate did not appear to adversely affect MITC performance. Trials to evaluate the performance of fused borate rods were sampled after 1 or 2 years of exposure. Chemical analysis of cores removed from the test poles revealed that none of the treatments contained boron at levels which would be considered adequate for arresting or preventing colonization by wood decay fungi. Interestingly, boron levels in poles exposed in Hilo, Hawaii were highest above the treatment hole, suggesting that some upward diffusion of this chemical is possible. The low boron levels in these poles are reason for concern, since a number of utilities are considering the using this formulation for remedial treatment at the groundline. Evaluations of new solid fumigants are progressing. Trials with Basamid indicate that the addition of copper compounds improved the rate of decomposition to produce MITC. Simultaneous addition of copper sulfate and Basamid may be useful for accelerating the decomposition of this compound, making it practical for control of internal decay fungi. Trials have been established to evaluate the performance of gelled and pelletized metham sodium and a sodium fluoride/boron rod. These trials will be evaluated in future reports. A third field trial to evaluate the performance of a copper naphthenate/boron paste for internal treatment of Douglas-fir poles is currently be evaluated to determine chemical levels 3 years after treatment. The performance of gelled metham sodium was further evaluated under laboratory conditions to better understand the performance of this chemical. Gelled metham sodium provided improved fungal control in comparison with liquid metham sodium and appeared to produce increased MITC levels under a variety of test conditions. The improved performance of this formulation may reflect the ability of the gell to retain moisture for longer periods of time than the liquid metham sodium formulation. Further studies of this formulation are underway. Laboratory studies were also performed to evaluate the effects of various additives on the performance of Basamid. Once again, the addition of copper compounds enhanced the production of MITC. A number of other compounds shifted decomposition to the production of carbon disulfide and carbonyl sulfide, two less fungitoxic compounds. Further studies are underway to identify non-sulfur products which may provide some protection against wood decay fungi. Evaluations of the effects of artificial voids on performance of fumigants in Douglas-fir poles indicate that voids had little or no effect on fumigant distribution. As a result, fumigant treatment of solid wood around voids represents a viable strategy for improving pole service life. Evaluation of timbers treated with metham sodium indicate that detectable levels of MITC were present one year after treatment. These timbers will be evaluated in subsequent years to determine the protective period provided by fumigants in sawn material. We continue development of a fumigant movement model using data previously developed on MITC. This year, we evaluated a previously developed system, ANSYS. Results of preliminary trials are similar to data previously developed on MITC-Fume treated poles and indicate that modeling MITC movement should be possible. Further trials are underway to confirm and expand this model. The effect of wood moisture content, temperature and wood species on metham sodium decomposition was investigated under laboratory conditions. The efficiency of dcomposition to MITC varied widely, but was most affected by temperature and wood moisture content. The results suggests that there is considerable potential for improving decomposition efficiency to enhance performance of this fumigant. Further studies to characterize the relationship between chemical content of the wood species and decomposition are underway. Field trials to identify safer treatments for preventing decay of cedar sapwood and protecting field drilled bolt holes are continuing. Diffusible treatments continue to provide excellent protection for field drilled bolt holes. A study to develop estimates of the extent of decay above the groundline in Douglas-fir poles in the Pacific Northwest is underway. The data from this study will be used to develop estimates of the potential for damage and provide some insight into the extent of this problem. Studies to develop guidelines for sterilization of Douglas-fir poles following air-seasoning are continuing. Evaluations of internal temperature development during kiln-drying were completed this year and indicate that internal temperatures during typical pole drying schedules were more than adequate for acheiving sterilization. Further evaluations of the data are underway to develop reliable heating curves for this process. Evaluations of groundline preservative systems have been established at Corvallis, OR and Merced, CA. The results indicate that all of the formulations are moving well through the wood in a manner similar to that found with pentachlorophenol-based systems. Chemical levels in some treatments; however, are beginning to decline 30 months after treatment. Studies are now underway to establish thresholds for combinations of the various formulations. Copper naphthenate treated western redcedar stakelets continue to perform well in fungus cellar trials. Stakes weathered prior to treatment are degrading slightly faster, while freshly sawn stakelets continue to perform well. Field trials have also been established to evaluate the performance of copper naphthenate treated Douglas-fir utility poles in California and Oregon. The chemical levels and fungal colonization will be monitored in these poles to provide a guide to performance of this chemical in western wood species. Title: Conserving energy by environmentally acceptable practices in maintaining and procuring transmission poles for long service ; August 1992 Author: Morrell, Jeffrey J., Oregon State University. Dept. of Forest Products, Corden, M. E. (Malcolm E.) Evaluation of previously established field trials of remedial internal treatments demonstrates the continued performance of chioropicrin, Vorlex, and methylisothiocyanate (MITC). While the degree of protection afforded by these treatments has declined with time, residual fungitoxic levels remain in many tests. Field trials of gelatin encapsulated MITC indicate that gelatin had no negative effect on fumigant performance even when no water was added at the time of treatment. Closed tube bioassays, chemical analyses, and culturing of Douglas-fir and southern pine poles treated with glass encapsulated METC (MITC-Fume) indicate that this chemical is outperforming metham sodium 3 years after application. While the glass vials lost chemical very slowly, the slow release rate did not appear to adversely affect MITC performance. Trials to evaluate the performance of fused borate rods were sampled after 1 or 2 years of exposure. Chemical analysis of cores removed from the test poles revealed that none of the treatments contained boron at levels which would be considered adequate for arresting or preventing colonization by wood decay fungi. Interestingly, boron levels in poles exposed in Hilo, Hawaii were highest above the treatment hole, suggesting that some upward diffusion of this chemical is possible. The low boron levels in these poles are reason for concern, since a number of utilities are considering the using this formulation for remedial treatment at the groundline. Evaluations of new solid fumigants are progressing. Trials with Basamid indicate that the addition of copper compounds improved the rate of decomposition to produce MITC. Simultaneous addition of copper sulfate and Basamid may be useful for accelerating the decomposition of this compound, making it practical for control of internal decay fungi. Trials have been established to evaluate the performance of gelled and pelletized metham sodium and a sodium fluoride/boron rod. These trials will be evaluated in future reports. A third field trial to evaluate the performance of a copper naphthenate/boron paste for internal treatment of Douglas-fir poles is currently be evaluated to determine chemical levels 3 years after treatment. The performance of gelled metham sodium was further evaluated under laboratory conditions to better understand the performance of this chemical. Gelled metham sodium provided improved fungal control in comparison with liquid metham sodium and appeared to produce increased MITC levels under a variety of test conditions. The improved performance of this formulation may reflect the ability of the gell to retain moisture for longer periods of time than the liquid metham sodium formulation. Further studies of this formulation are underway. Laboratory studies were also performed to evaluate the effects of various additives on the performance of Basamid. Once again, the addition of copper compounds enhanced the production of MITC. A number of other compounds shifted decomposition to the production of carbon disulfide and carbonyl sulfide, two less fungitoxic compounds. Further studies are underway to identify non-sulfur products which may provide some protection against wood decay fungi. Evaluations of the effects of artificial voids on performance of fumigants in Douglas-fir poles indicate that voids had little or no effect on fumigant distribution. As a result, fumigant treatment of solid wood around voids represents a viable strategy for improving pole service life. Evaluation of timbers treated with metham sodium indicate that detectable levels of MITC were present one year after treatment. These timbers will be evaluated in subsequent years to determine the protective period provided by fumigants in sawn material. We continue development of a fumigant movement model using data previously developed on MITC. This year, we evaluated a previously developed system, ANSYS. Results of preliminary trials are similar to data previously developed on MITC-Fume treated poles and indicate that modeling MITC movement should be possible. Further trials are underway to confirm and expand this model. The effect of wood moisture content, temperature and wood species on metham sodium decomposition was investigated under laboratory conditions. The efficiency of dcomposition to MITC varied widely, but was most affected by temperature and wood moisture content. The results suggests that there is considerable potential for improving decomposition efficiency to enhance performance of this fumigant. Further studies to characterize the relationship between chemical content of the wood species and decomposition are underway. Field trials to identify safer treatments for preventing decay of cedar sapwood and protecting field drilled bolt holes are continuing. Diffusible treatments continue to provide excellent protection for field drilled bolt holes. A study to develop estimates of the extent of decay above the groundline in Douglas-fir poles in the Pacific Northwest is underway. The data from this study will be used to develop estimates of the potential for damage and provide some insight into the extent of this problem. Studies to develop guidelines for sterilization of Douglas-fir poles following air-seasoning are continuing. Evaluations of internal temperature development during kiln-drying were completed this year and indicate that internal temperatures during typical pole drying schedules were more than adequate for acheiving sterilization. Further evaluations of the data are underway to develop reliable heating curves for this process. Evaluations of groundline preservative systems have been established at Corvallis, OR and Merced, CA. The results indicate that all of the formulations are moving well through the wood in a manner similar to that found with pentachlorophenol-based systems. Chemical levels in some treatments; however, are beginning to decline 30 months after treatment. Studies are now underway to establish thresholds for combinations of the various formulations. Copper naphthenate treated western redcedar stakelets continue to perform well in fungus cellar trials. Stakes weathered prior to treatment are degrading slightly faster, while freshly sawn stakelets continue to perform well. Field trials have also been established to evaluate the performance of copper naphthenate treated Douglas-fir utility poles in California and Oregon. The chemical levels and fungal colonization will be monitored in these poles to provide a guide to performance of this chemical in western wood species. Close

• 5. [Article] Conserving energy by environmentally acceptable practices in maintaining and procuring transmission poles for long service ; August 1991

  Evaluations of previously established field trials indicate that chioropicrin and Vorlex continue to provide a diminishing level of protection to Douglas-fir poles. Tests of solid methylisothiocyanate ...

  Citation × Citation Citation Abstract Copy Title: Conserving energy by environmentally acceptable practices in maintaining and procuring transmission poles for long service ; August 1991 Author: Morrell, Jeffrey J., Oregon State University. Dept. of Forest Products, Corden, M. E. (Malcolm E.) Evaluations of previously established field trials indicate that chioropicrin and Vorlex continue to provide a diminishing level of protection to Douglas-fir poles. Tests of solid methylisothiocyanate (MITC), now in their thirteenth year, indicate that this chemical continues to prevent recolonization of Douglas-fir poles by decay fungi. MITC appears to provide equivalent or better protection than Vorlex. Gelatin encapsulated MITC and chioropicrin also continue to perform well in field trials. Although the gelatin is water soluble and must decompose to release the chemical, the addition of water to the treatment holes did not appear to significantly enhance long-term MITC performance. Laboratory trials to identify safer fumigants indicate that sodium nmethyldithiocarbamate decomposition occurs even in dry wood, although the rate of decomposition is enhanced by the presence of some moisture. A gelled 40 % NaMDC formulation has also been evaluated for its ability to eliminate decay fungi from Douglas-fir heartwood. This formulation has performed better than liquid metham sodium. Field trials are planned with both the solid and gelled NaMDC. Laboratory trials have also been performed to evaluate the toxicity of fused borate rods to Antrodia carbonica and Postia placenta. These two fungi are important decayers of Douglas-fir utility poles. The results indicate that the boron moved well through both wood species, but complete elimination of the test fungus required 6 to 8 weeks. Antrodia carbonica was generally more tolerant of boron than P. placenta. Field trials of fused borate rods indicate that the boron has moved downward from the point of application, but no evidence of upward movement was noted. Trials to evaluate the efficacy of glass-encapsulated M:[TC in Douglas-fir 1 11 and southern pine poles are now in their second year. The results continue to indicate the MITC levels are higher in Douglas-fir poles. The reasons for this descrepancy are unclear, but may reflect an increased MITC loss from the more permeable southern pine poles. Controlled studies of MITC release rates from the glass vials show that the tubes retain chemical for 1 to 2 years under normal conditions. Faster losses occur under more tropical conditions, while little loss occurs in cold conditions. Evaluations of additives to enhance Basamid decomposition in Douglas-fir pole sections indicate that the presence of copper sulfate and pH 12 buffer markedly improve the rate of decomposition to MuG one year after chemical application. More controlled laboratory studies are underway to better understand this effect. The trials to evaluate the effects of voids on fumigant movement continue to indicate that the void has little effect on chemical concentration. These results indicate that fumigant treatment of poles with voids is feasible provided the wood retains adequate strength. Laboratory trials to develop diffusion coefficients for chloropicri.n movement through Douglas-fir heartwood have been developed. As expected, chioropicrin movement was most rapid longitudinally and at the fiber saturation point. Drier wood retained more chemical, slowing diffusion. The diffusion coefficients will be employed in the fumigant model currently being evaluated on MITC. The model indicates that MITC movement was greatest at moderate moisture levels (22 or 44 %), while higher or lower moisture regimes limited chemical movement. The results obtained using the model will be confirmed through laboratory trials and by comparison with the results of chemical analyses performed on the glass-encapsulated MITC trials. The trials to identify potential replacements for pentachlorophenol for Ii' remedial treatments are continuing. A number of chemicals have been identified for both the protection of field drilled bolt holes and the spray treatment of western redcedar sapwood. Spray treatments of the most promising chemicals will be applied to western redcedar poles in service. The identification of small scale tests for detecting decay or estimating residual strength are continuing. We also continue to evaluate the effectiveness of various pretreatments for improving treatment and performance of poles. The effects of through boring and radial drilling patterns on treatment were evaluated on a glue-laminated Douglas-fir pole. While some differences were noted in the patterns, the pole was too well-treated to permit effective separation of the various patterns. The air-seasoning studies are now completed. Evaluation of the final pahse of this study showed that decay fungi began to colonize the pole sections after only 3 months of air-seasoning. Examination of weather data failed to provide a conclusive relationship between climate and colonization, possibly due to the array of variables to which the seasoning wood is subjected. The test suggests that most poles are adequately dried within three months of air-seasoning so that short air-seasoning exposures could be feasible. Sterilization at some point during the treatment cycle should still be considered as an integral part in the proper treatment of poles. Field trials to evaluate the performance of modified groundline wrap systems are continuing at both the Corvallis site and on a test line near Modesto, CA. The results at the Corvallis site indicate the copper naphthenate, boron, and fluoride are all moving well into the wood eighteen months after application. More controlled laboratory trials on one formulation suggest that the water soluble copper naphthenate can migrate for some distance into the wood within six months after application. As expected, wet wood permits more iv substantial diffusion. Evaluation of copper naphthenate treated western redcedar stakes in a fungus cellar suggests that the specified treatment levels are providing adequate protection, although some decay is occurring. Stakes which were obtained from weathered sapwood appear to be failing more rapidly those cut from freshly sawn lumber, possibly because the former stakes have a more open structure which permits leaching losses and subsequent fungal colonization. Title: Conserving energy by environmentally acceptable practices in maintaining and procuring transmission poles for long service ; August 1991 Author: Morrell, Jeffrey J., Oregon State University. Dept. of Forest Products, Corden, M. E. (Malcolm E.) Evaluations of previously established field trials indicate that chioropicrin and Vorlex continue to provide a diminishing level of protection to Douglas-fir poles. Tests of solid methylisothiocyanate (MITC), now in their thirteenth year, indicate that this chemical continues to prevent recolonization of Douglas-fir poles by decay fungi. MITC appears to provide equivalent or better protection than Vorlex. Gelatin encapsulated MITC and chioropicrin also continue to perform well in field trials. Although the gelatin is water soluble and must decompose to release the chemical, the addition of water to the treatment holes did not appear to significantly enhance long-term MITC performance. Laboratory trials to identify safer fumigants indicate that sodium nmethyldithiocarbamate decomposition occurs even in dry wood, although the rate of decomposition is enhanced by the presence of some moisture. A gelled 40 % NaMDC formulation has also been evaluated for its ability to eliminate decay fungi from Douglas-fir heartwood. This formulation has performed better than liquid metham sodium. Field trials are planned with both the solid and gelled NaMDC. Laboratory trials have also been performed to evaluate the toxicity of fused borate rods to Antrodia carbonica and Postia placenta. These two fungi are important decayers of Douglas-fir utility poles. The results indicate that the boron moved well through both wood species, but complete elimination of the test fungus required 6 to 8 weeks. Antrodia carbonica was generally more tolerant of boron than P. placenta. Field trials of fused borate rods indicate that the boron has moved downward from the point of application, but no evidence of upward movement was noted. Trials to evaluate the efficacy of glass-encapsulated M:[TC in Douglas-fir 1 11 and southern pine poles are now in their second year. The results continue to indicate the MITC levels are higher in Douglas-fir poles. The reasons for this descrepancy are unclear, but may reflect an increased MITC loss from the more permeable southern pine poles. Controlled studies of MITC release rates from the glass vials show that the tubes retain chemical for 1 to 2 years under normal conditions. Faster losses occur under more tropical conditions, while little loss occurs in cold conditions. Evaluations of additives to enhance Basamid decomposition in Douglas-fir pole sections indicate that the presence of copper sulfate and pH 12 buffer markedly improve the rate of decomposition to MuG one year after chemical application. More controlled laboratory studies are underway to better understand this effect. The trials to evaluate the effects of voids on fumigant movement continue to indicate that the void has little effect on chemical concentration. These results indicate that fumigant treatment of poles with voids is feasible provided the wood retains adequate strength. Laboratory trials to develop diffusion coefficients for chloropicri.n movement through Douglas-fir heartwood have been developed. As expected, chioropicrin movement was most rapid longitudinally and at the fiber saturation point. Drier wood retained more chemical, slowing diffusion. The diffusion coefficients will be employed in the fumigant model currently being evaluated on MITC. The model indicates that MITC movement was greatest at moderate moisture levels (22 or 44 %), while higher or lower moisture regimes limited chemical movement. The results obtained using the model will be confirmed through laboratory trials and by comparison with the results of chemical analyses performed on the glass-encapsulated MITC trials. The trials to identify potential replacements for pentachlorophenol for Ii' remedial treatments are continuing. A number of chemicals have been identified for both the protection of field drilled bolt holes and the spray treatment of western redcedar sapwood. Spray treatments of the most promising chemicals will be applied to western redcedar poles in service. The identification of small scale tests for detecting decay or estimating residual strength are continuing. We also continue to evaluate the effectiveness of various pretreatments for improving treatment and performance of poles. The effects of through boring and radial drilling patterns on treatment were evaluated on a glue-laminated Douglas-fir pole. While some differences were noted in the patterns, the pole was too well-treated to permit effective separation of the various patterns. The air-seasoning studies are now completed. Evaluation of the final pahse of this study showed that decay fungi began to colonize the pole sections after only 3 months of air-seasoning. Examination of weather data failed to provide a conclusive relationship between climate and colonization, possibly due to the array of variables to which the seasoning wood is subjected. The test suggests that most poles are adequately dried within three months of air-seasoning so that short air-seasoning exposures could be feasible. Sterilization at some point during the treatment cycle should still be considered as an integral part in the proper treatment of poles. Field trials to evaluate the performance of modified groundline wrap systems are continuing at both the Corvallis site and on a test line near Modesto, CA. The results at the Corvallis site indicate the copper naphthenate, boron, and fluoride are all moving well into the wood eighteen months after application. More controlled laboratory trials on one formulation suggest that the water soluble copper naphthenate can migrate for some distance into the wood within six months after application. As expected, wet wood permits more iv substantial diffusion. Evaluation of copper naphthenate treated western redcedar stakes in a fungus cellar suggests that the specified treatment levels are providing adequate protection, although some decay is occurring. Stakes which were obtained from weathered sapwood appear to be failing more rapidly those cut from freshly sawn lumber, possibly because the former stakes have a more open structure which permits leaching losses and subsequent fungal colonization. Close

• 6. [Article] Conserving energy by environmentally acceptable practices in maintaining and procuring transmission poles for long service ; August 1987

  This seventh annual report outlines our continued progress on each of six objectives. Improved fumigants: We continue to evaluate previously established field tests, which inlicate that chioropicrin continues ...

  Citation × Citation Citation Abstract Copy Title: Conserving energy by environmentally acceptable practices in maintaining and procuring transmission poles for long service ; August 1987 Author: Morrell, Jeffrey J., Oregon State University. Dept. of Forest Products, Corden, M. E. (Malcolm E.) This seventh annual report outlines our continued progress on each of six objectives. Improved fumigants: We continue to evaluate previously established field tests, which inlicate that chioropicrin continues to protect Douglas-fir poles after 17 years and piling after 12 years. Vorlex treated poles are being gradually recolonized by decay fungi, while the Vapam treated poles appear to have little resistance to decay fungi. The latter poles were retreated last summer and will be used to determine the effectiveness of fumigant retreatment. Solid methylisothiocyanate (NIT) continues to protect Douglasfir poles, although the 20 percent NIT treatment has experienced slightly higher levels of colonization after 9 years. Additional tests to evaluate the effectiveness of gelatin encapsulated MIT or chioropicrin indicate that both chemicals continue to remain effective. In addition, there now appears to be little difference between the levels of control exhibited following addition of varying amounts of water to the poles along with gelatin encapsulated NIT. Closed tube bioassays indicate the chioropicrin remains at fungitoxic levels after 17 years, while no volatile fungitoxins appear to be present in Vapam or Vorlex treated wood. The evaluation of untreated Douglas-fir posts treated with NIT, chloropicrin, or Vapam indicate that fumigants can not ccatletely protect untreated wood in ground contact unless there is sane other type of preservative treated barrier present. Although the NIT treatment provided the best protection, all of the posts experienced some surface decay and termite attack after 10 years. These results appear similar to those found with more recent tests of posts treated with various coLthinations of preservative containing wraps and fuinigants. Evaluation of Mylone and tridipain, two solid chemicals that degrade to produce NIT, initcates that NIT production and fungal control are enhanced by the addition of basic pH buffers; however, only the pH 12 buffer resulted in rapid fungal control. These results Jnitcate that the rate of fumigant release can be tailored to control specific decay problems. We have also investigated the decomposition of Vapam in wood. As previously reported, there are over 14 potential deccmposition products from this chemical. This past year we developed methods for assaying these chemicals, evaluated the long-term stability of each, and prepared test blocks for evaluating decc*,osjtion in wood. In addition, we have studied the migration of volatile compounds from Vapam and NIT treated blocks under controlled aeration. After 5,000 hours, detectable levesis of NIT, carbon disulfide, and carbon oxysulfide are still present in air surrounding the Douglas-fir blocks. These tests indicate that low levels of volatile chemicals are continuously eninitted from fumigant treated wood. While this poses little difficulty for utility poles, it may pose some hazard for wood in closed spaces. Evaluations will continue until the emission levels decline below detectable limits. In addition to Vapam deccmposition studies, we have also evaluated the decoxrosition, movement and fungitoxicity of NIT under a variety of environmental conditions. In general, wet wood held less NIT, but the degree of control produced was more rapid. These results suggest that dry wood will act as a reseivoir of NIT, which will be released as moisture enters and swells the wood. This effect may provide an excellent long-term decay control strategy. The information from these studies will be used to develop more 111 ecific recaimrndations for fumigant treatment. Cedar Saood Decay Control: This past year we reestablished the field test of promising nei pentachiorophenol replacements, incorporating 26 chemicals into these tests. These saitles will be evaluated after 1 and 2 years to determine efficacy. In addition to the field test, we evaluated 13 new formulations or cinations of formulations in our laboratory screening tests. A nuner of chemicals including Isothiazolone, Amical 48 and a nurrer of quaternary aimnonium compounds appear promising and have been included in the field test. Bolt Hole Decay Prevention: Test established 5 years ago to determine the effectiveness of sprays, liquids or pastes applied to field drilled bolts holes indicate that airanonium bifluoride, Boracol 40, and 10% penta provided greater protection than Polybor or Patox washers. In addition, no evidence of corrosion was associated with any of the treatments. Fumigant treatments below the bolt holes continue to eliminate decay fungi, although samples removed from further down the pole indicate an incoIr)1ete distribution of MIT. These tests will be reevaluated this coming year. Detecting Early Decay and Estimating Residual Strength: We continue to evaluate the use of fluorescent coupled lectins and infra-red spectroscopy for detecting fungi in wood and early decay under controlled laboratory conditions. We have also continued evaluation of longitudinal compression (L) as a measure of ultite wood strength using a series of 27 Ldgepole pine posts. While the dense knot clusters interferred with the analysis, LCS, in combination with other parameters, was a reasonably good predictor of bending strength. These tests will continue with more uniform material. iv In addition to tests of LCS, we have evaluated the ability of small scal e tests to determine the strength of various wood pole connectors. Out results were in close agreement with those obtained using full scale tests aii illustrate the value of using small r1 e tests to develop strength information. Initiation of Decay in Air-Seasoning Douglas-fir: We continue to evaluate the data developed in the air-seasoning st1wies. This past year we began to develop information on the effects of various colony sizes on wood strength. This data will help us assign strength values to the colony size data we ha developed frau the air-seasoning study. At present, only Peniophora spp. has been tested, but . carbonica, P. placenta, and Haematostereum sanguinolentuin will also be included. Evaluation of the teinperatures required to eliminate fungi from Douglas-f ir poles also continue. We have ccatpleted 9 test charges which indicate that the penta treatmants involving a Boulton-seasoning cycle result in a ixre than adequate heating of the wood, while steam treants associated with amnniacal copper arsenate are nre variable. We feel that longer heating periods are required for poles greater than 12 inches in diamater, but that the current 6 hour steam period will result in heating of the center to 67 C for over 1 hour in smaller poles. Microfungi in Douglas-fir Poles: We continue to evaluate the effects of nticrofungi on properties of fumigant treated Douglas-fir poles. These tests indicate that prior colonization of fumigant treated wood by Scytalidium or Trichoderma species resulted in lower weight losses by P. placenta and . carbonica. Evaluation of a Cellon treated Douglas-fir laminated beam indicated that V severe penta depletion was associated with virtually all of the surface decay present. This beam had only been in service for 12 years in an extremely dry climate arxl it is unclear why the decay was so rapid. Title: Conserving energy by environmentally acceptable practices in maintaining and procuring transmission poles for long service ; August 1987 Author: Morrell, Jeffrey J., Oregon State University. Dept. of Forest Products, Corden, M. E. (Malcolm E.) This seventh annual report outlines our continued progress on each of six objectives. Improved fumigants: We continue to evaluate previously established field tests, which inlicate that chioropicrin continues to protect Douglas-fir poles after 17 years and piling after 12 years. Vorlex treated poles are being gradually recolonized by decay fungi, while the Vapam treated poles appear to have little resistance to decay fungi. The latter poles were retreated last summer and will be used to determine the effectiveness of fumigant retreatment. Solid methylisothiocyanate (NIT) continues to protect Douglasfir poles, although the 20 percent NIT treatment has experienced slightly higher levels of colonization after 9 years. Additional tests to evaluate the effectiveness of gelatin encapsulated MIT or chioropicrin indicate that both chemicals continue to remain effective. In addition, there now appears to be little difference between the levels of control exhibited following addition of varying amounts of water to the poles along with gelatin encapsulated NIT. Closed tube bioassays indicate the chioropicrin remains at fungitoxic levels after 17 years, while no volatile fungitoxins appear to be present in Vapam or Vorlex treated wood. The evaluation of untreated Douglas-fir posts treated with NIT, chloropicrin, or Vapam indicate that fumigants can not ccatletely protect untreated wood in ground contact unless there is sane other type of preservative treated barrier present. Although the NIT treatment provided the best protection, all of the posts experienced some surface decay and termite attack after 10 years. These results appear similar to those found with more recent tests of posts treated with various coLthinations of preservative containing wraps and fuinigants. Evaluation of Mylone and tridipain, two solid chemicals that degrade to produce NIT, initcates that NIT production and fungal control are enhanced by the addition of basic pH buffers; however, only the pH 12 buffer resulted in rapid fungal control. These results Jnitcate that the rate of fumigant release can be tailored to control specific decay problems. We have also investigated the decomposition of Vapam in wood. As previously reported, there are over 14 potential deccmposition products from this chemical. This past year we developed methods for assaying these chemicals, evaluated the long-term stability of each, and prepared test blocks for evaluating decc*,osjtion in wood. In addition, we have studied the migration of volatile compounds from Vapam and NIT treated blocks under controlled aeration. After 5,000 hours, detectable levesis of NIT, carbon disulfide, and carbon oxysulfide are still present in air surrounding the Douglas-fir blocks. These tests indicate that low levels of volatile chemicals are continuously eninitted from fumigant treated wood. While this poses little difficulty for utility poles, it may pose some hazard for wood in closed spaces. Evaluations will continue until the emission levels decline below detectable limits. In addition to Vapam deccmposition studies, we have also evaluated the decoxrosition, movement and fungitoxicity of NIT under a variety of environmental conditions. In general, wet wood held less NIT, but the degree of control produced was more rapid. These results suggest that dry wood will act as a reseivoir of NIT, which will be released as moisture enters and swells the wood. This effect may provide an excellent long-term decay control strategy. The information from these studies will be used to develop more 111 ecific recaimrndations for fumigant treatment. Cedar Saood Decay Control: This past year we reestablished the field test of promising nei pentachiorophenol replacements, incorporating 26 chemicals into these tests. These saitles will be evaluated after 1 and 2 years to determine efficacy. In addition to the field test, we evaluated 13 new formulations or cinations of formulations in our laboratory screening tests. A nuner of chemicals including Isothiazolone, Amical 48 and a nurrer of quaternary aimnonium compounds appear promising and have been included in the field test. Bolt Hole Decay Prevention: Test established 5 years ago to determine the effectiveness of sprays, liquids or pastes applied to field drilled bolts holes indicate that airanonium bifluoride, Boracol 40, and 10% penta provided greater protection than Polybor or Patox washers. In addition, no evidence of corrosion was associated with any of the treatments. Fumigant treatments below the bolt holes continue to eliminate decay fungi, although samples removed from further down the pole indicate an incoIr)1ete distribution of MIT. These tests will be reevaluated this coming year. Detecting Early Decay and Estimating Residual Strength: We continue to evaluate the use of fluorescent coupled lectins and infra-red spectroscopy for detecting fungi in wood and early decay under controlled laboratory conditions. We have also continued evaluation of longitudinal compression (L) as a measure of ultite wood strength using a series of 27 Ldgepole pine posts. While the dense knot clusters interferred with the analysis, LCS, in combination with other parameters, was a reasonably good predictor of bending strength. These tests will continue with more uniform material. iv In addition to tests of LCS, we have evaluated the ability of small scal e tests to determine the strength of various wood pole connectors. Out results were in close agreement with those obtained using full scale tests aii illustrate the value of using small r1 e tests to develop strength information. Initiation of Decay in Air-Seasoning Douglas-fir: We continue to evaluate the data developed in the air-seasoning st1wies. This past year we began to develop information on the effects of various colony sizes on wood strength. This data will help us assign strength values to the colony size data we ha developed frau the air-seasoning study. At present, only Peniophora spp. has been tested, but . carbonica, P. placenta, and Haematostereum sanguinolentuin will also be included. Evaluation of the teinperatures required to eliminate fungi from Douglas-f ir poles also continue. We have ccatpleted 9 test charges which indicate that the penta treatmants involving a Boulton-seasoning cycle result in a ixre than adequate heating of the wood, while steam treants associated with amnniacal copper arsenate are nre variable. We feel that longer heating periods are required for poles greater than 12 inches in diamater, but that the current 6 hour steam period will result in heating of the center to 67 C for over 1 hour in smaller poles. Microfungi in Douglas-fir Poles: We continue to evaluate the effects of nticrofungi on properties of fumigant treated Douglas-fir poles. These tests indicate that prior colonization of fumigant treated wood by Scytalidium or Trichoderma species resulted in lower weight losses by P. placenta and . carbonica. Evaluation of a Cellon treated Douglas-fir laminated beam indicated that V severe penta depletion was associated with virtually all of the surface decay present. This beam had only been in service for 12 years in an extremely dry climate arxl it is unclear why the decay was so rapid. Close

• 7. [Article] Conserving energy by safe and environmentally acceptable practices in maintaining and procuring transmission poles for long service ; August 1985

  This fifth annual Cooperative Pole Research Program report outlines our progress in the six project objectives. Improved Fumigants Sampling of previously established field tests revealed that Vorlex and ...

  Citation × Citation Citation Abstract Copy Title: Conserving energy by safe and environmentally acceptable practices in maintaining and procuring transmission poles for long service ; August 1985 Author: Oregon State University, Oregon State University. Dept. of Forest Products This fifth annual Cooperative Pole Research Program report outlines our progress in the six project objectives. Improved Fumigants Sampling of previously established field tests revealed that Vorlex and Chloropicrin continued to perform well after 15 years, while Vapam was slightly less effective. Solid methylisothiocyanate (MIT) also performed well in the field after 7 years. In additional tests, gelatin encapsulated MIT migrated through Douglas-fir heartwood with addition of moderate quantities of water to degrade the gelatin. However, in the presence of higher quantities of water or no additional water, MIT migration into the wood was slowed. In a previously established test, gelatin encapsulated MIT continues to inhibit reinfestation of poles 3 years after treatment. Pelletized MIT is a new formulation (65% active ingredient) that appears to have some promise. Preliminary tests indicate that up to 95% of the MIT is release in 24 hours, but a small quantity of MIT remains in the pellets after 63 days aeration and may pose a disposal hazard. The solid MIT formulations will permit aboveground applications, increasing the risk that MIT will come in contact with pole hardware. Preliminary tests indicate that MIT had little effect on corrosion of hot dipped, galvanized bolts attached to wood. This suggests that treatment in the crossarm zone with MIT or fumigants that produce MIT should not affect the integrity of attached hardware. i-i In addition to fumigant evaluations, we recently examined an earlier test of groundline treatments with Osmoplastic® and Hollowheart®. After 10 years, these treatments are performing reasonably well, with only a slight rise in the incidence of decay fungi in the past 4 years. We also reevaluated the effectiveness of kerfing for preventing decay and found that this process reduced the depth and width of checks, resulting in a decreased incidence of decay fungi. Kerfing appears to be a valuable method for preventing internal decay at the groundline. Cedar Sapwood Decay Control This past year, the second set of five chemicals applied to control sapwood decay were evaluated after 2 years of exposure. As in earlier evaluations using the Aspergillus bioassay, none of the chemicals approach pentachlorophenol in oil for ability to inhibit sporulation of Aspergillus niger; however, several samples from zones deep in the wood produced a slight zone of effect. This may indicate the presence of a reservoir for long-term protection against decay. Several of the chemicals including Fluor Chrome Arsenic Phenol and Ammoniacal Copper Arsenate (ACA) appear to bind to the wood and may be difficult to detect by the bioassay method. We expect to assess the effectiveness of these treatments using a soil block test. Investigations of the reliability of the Aspergillus bioassay under a variety of conditions indicated that quantity of spores, use of glass or plastic petri dishes, long-term cold storage, and the use of spray inoculum instead of flooding spores had little influence on the bioassay results with pentachiorophenol, Tributyl-tinoxide, or 3 iodo propynyl butylcarbamate; however, incubation temperature did influence assay results. The Aspergillus bioassay is a simple, effective means for estimating residual preservative levels. Bolt Holes Again this year, wood around the unprotected, control bolt holes in pole sections contained such low levels of decay fungi that evaluation of the treated poles will be delayed another year. In addition to the initial bolt hole treatments, we have begun a test to determine if gelatin encapsulated or pelletized MIT can prevent decay development in field-drilled bolt holes. The pole sections used in these tests had already begun to develop decay prior to treatment and will provide an ideal test material. Detecting Decay and Estimatin& Residual Strength of Poles Fluorescent labeled lectins used in our earlier studies detected decay fungi at low weight losses under laboratory conditions. We are currently evaluating this method for detecting fungi in increment cores removed from poles to reduce the need for culturing. Last year we identified a peak that was unique to infrared (IR) spectra of warm water extracts from decayed wood. This past year we attempted to identify the chemical responsible for this peak and found that carbonyl compounds, probably from oxidative lignin degradation, were responsible for the peak. Since brown rot fungi apparently do iv not completely metabolize lignin breakdown products, they accumulate in the decaying wood and can be readily detected by their IR spectra. Strength properties of beams cut front Douglas-fir pole sections, air-seasoned for 3 years significantly decreased although decay fungi could not be uniformly isolated from the beams. In addition, there were gradual declines in work to maximum load and modulus of elasticity, as well as increased Pilodyn pin penetration. These results suggest that some strength losses occurred during air-seasoning; however, the losses were not large and should not endanger pole users. We compared several test methods including the Pilodyn, radial compression tests, longitudinal compression tests, and the pick test for evaluating residual pole strength of the wood surface of Douglas-fir treated with combinations of funtigants or groundline wraps. The results indicate that only the pick test could accurately detect surface damage and illustrate the difficulty of detecting surface damage. This past year we evaluated several sections cut from ACA treated poles stored for a number of years to determine if they were worth salvaging. Static bending tests of beams cut from the ACA treated zone, the treated/untreated boundary, and the inner heartwood revealed ACA treated sapwood had lower MOR and longitudinal compression strength than the other zones. These results represent only a small sample, but they suggest that some strength loss occurs during ACA V treatments. More importantly, the results suggest that we could have reliably predicted beam MOR by testing small plugs removed from the poles. Small beams cut from decaying, pentachlorophenol treated Douglas-fir poles were acoustically tested for residual wood strength, then evaluated to failure in static bending. The acoustic test consisted of sending a pulsed sonic wave into the wood and recording this wave after it passed through the beam. As it moved, the wave was altered by the presence of any wood defects or decay, and these alterations create a "fingerprint" specific for that defect. Preliminary results indicated that signal analysis was highly 2 2 correlated with work to maximum load (r =.82) and MOR (r .88), suggesting that this approach to decay detection may prove more reliable than measuring of sound velocity. Initiation of Decay in Air-Seasoning Douglas-fir The results of the initial survey to determine the incidence of decay fungi in poles from widely scattered Pacific Northwest seasoning yards indicated that a variety of fungi were colonizing the wood. While most of these fungi do not pose a serious decay problem, two species, Poria carbonica and Poria placenta, became increasingly abundant with length of air-seasoning. These fungi are also the most conunon decayers of Douglas-fir poles in service. As expected, the number of fungi and the wood volume they occupied increased with seasoning time; however, this incidence varied considerably between yards, especially in poles air-seasoned for vi shorter time periods. In addition to the variation between sites, many of the decay fungi colonizing the wood appear to be monokaryons, indicating that spores landing on the wood are initiating the infestation. The distribution of fungi within the poles indicated that several of the more abundant decay fungi were present in the outer sapwood where they would be eliminated by conventional pressure treatment. The remaining fungi were most abundant in the heartwood but were more concentrated near the pole end. This suggests that exposed end grain was more readily invaded than lateral grain exposed in checks. In addition to identifying the fungi colonizing Douglas-fir, we examined the effects these fungi had on wood strength. Toughness tests indicated the presence of wide variation in decay capability of the isolates. Although there was no consistent pattern, most of the isolates did not cause substantial decay and, of those that did, only . carbonica and P. placenta were sufficiently abundant to have a large influence on wood strength. Due to the prevalence of P. carbonica and P. placenta in the inner heartwood, where they might not be eliminated in a short heating cycle, we evaluated the temperature tolerance of these two fungi in Douglas-fir heartwood blocks. These tests indicated that both fungi were eliminated by exposure to temperatures above 71°C for over 1 hour or 60°C for 2 hours. The results suggest that careful control of temperature during treatment should eliminate decay fungi and that wood treated at ambient temperatures should be heated to kill fungi that become established during air-seasoning. vii This past year was the third and final year of the decay development study. In this study, sterile pole sections have been exposed for 1, 2, or 3 years at widely scattered Pacific Northwest sites, then returned to the laboratory and extensively sampled. We are now in the process of identifying the fungi from the third year poles. In addition to examining poles prior to preservative treatment, we are also evaluating poles treated with waterborne chemicals (ACA or CCA) for the incidence of surface decay. This past year we examined twenty ACA-treated poles from a line installed in 1946. While a variety of fungi were cultured from the wood, none of the poles had evidence of substantial surface deterioration. A study was initiated on the fungal flora of fumigant treated wood because of the potential for fungi developing resistance to low levels of fumigant or the ability to actively degrade the chemical. Both of these developments could shorten fumigant retreatment cycles and increase maintenance costs. We have evaluated poles treated 7 and 15 years ago with fumigants and find markedly reduced fungal flora. Tests are continuing on the fungi isolated, and we hope to assess the effects of these isolates on long-term fumigant effectiveness. Title: Conserving energy by safe and environmentally acceptable practices in maintaining and procuring transmission poles for long service ; August 1985 Author: Oregon State University, Oregon State University. Dept. of Forest Products This fifth annual Cooperative Pole Research Program report outlines our progress in the six project objectives. Improved Fumigants Sampling of previously established field tests revealed that Vorlex and Chloropicrin continued to perform well after 15 years, while Vapam was slightly less effective. Solid methylisothiocyanate (MIT) also performed well in the field after 7 years. In additional tests, gelatin encapsulated MIT migrated through Douglas-fir heartwood with addition of moderate quantities of water to degrade the gelatin. However, in the presence of higher quantities of water or no additional water, MIT migration into the wood was slowed. In a previously established test, gelatin encapsulated MIT continues to inhibit reinfestation of poles 3 years after treatment. Pelletized MIT is a new formulation (65% active ingredient) that appears to have some promise. Preliminary tests indicate that up to 95% of the MIT is release in 24 hours, but a small quantity of MIT remains in the pellets after 63 days aeration and may pose a disposal hazard. The solid MIT formulations will permit aboveground applications, increasing the risk that MIT will come in contact with pole hardware. Preliminary tests indicate that MIT had little effect on corrosion of hot dipped, galvanized bolts attached to wood. This suggests that treatment in the crossarm zone with MIT or fumigants that produce MIT should not affect the integrity of attached hardware. i-i In addition to fumigant evaluations, we recently examined an earlier test of groundline treatments with Osmoplastic® and Hollowheart®. After 10 years, these treatments are performing reasonably well, with only a slight rise in the incidence of decay fungi in the past 4 years. We also reevaluated the effectiveness of kerfing for preventing decay and found that this process reduced the depth and width of checks, resulting in a decreased incidence of decay fungi. Kerfing appears to be a valuable method for preventing internal decay at the groundline. Cedar Sapwood Decay Control This past year, the second set of five chemicals applied to control sapwood decay were evaluated after 2 years of exposure. As in earlier evaluations using the Aspergillus bioassay, none of the chemicals approach pentachlorophenol in oil for ability to inhibit sporulation of Aspergillus niger; however, several samples from zones deep in the wood produced a slight zone of effect. This may indicate the presence of a reservoir for long-term protection against decay. Several of the chemicals including Fluor Chrome Arsenic Phenol and Ammoniacal Copper Arsenate (ACA) appear to bind to the wood and may be difficult to detect by the bioassay method. We expect to assess the effectiveness of these treatments using a soil block test. Investigations of the reliability of the Aspergillus bioassay under a variety of conditions indicated that quantity of spores, use of glass or plastic petri dishes, long-term cold storage, and the use of spray inoculum instead of flooding spores had little influence on the bioassay results with pentachiorophenol, Tributyl-tinoxide, or 3 iodo propynyl butylcarbamate; however, incubation temperature did influence assay results. The Aspergillus bioassay is a simple, effective means for estimating residual preservative levels. Bolt Holes Again this year, wood around the unprotected, control bolt holes in pole sections contained such low levels of decay fungi that evaluation of the treated poles will be delayed another year. In addition to the initial bolt hole treatments, we have begun a test to determine if gelatin encapsulated or pelletized MIT can prevent decay development in field-drilled bolt holes. The pole sections used in these tests had already begun to develop decay prior to treatment and will provide an ideal test material. Detecting Decay and Estimatin& Residual Strength of Poles Fluorescent labeled lectins used in our earlier studies detected decay fungi at low weight losses under laboratory conditions. We are currently evaluating this method for detecting fungi in increment cores removed from poles to reduce the need for culturing. Last year we identified a peak that was unique to infrared (IR) spectra of warm water extracts from decayed wood. This past year we attempted to identify the chemical responsible for this peak and found that carbonyl compounds, probably from oxidative lignin degradation, were responsible for the peak. Since brown rot fungi apparently do iv not completely metabolize lignin breakdown products, they accumulate in the decaying wood and can be readily detected by their IR spectra. Strength properties of beams cut front Douglas-fir pole sections, air-seasoned for 3 years significantly decreased although decay fungi could not be uniformly isolated from the beams. In addition, there were gradual declines in work to maximum load and modulus of elasticity, as well as increased Pilodyn pin penetration. These results suggest that some strength losses occurred during air-seasoning; however, the losses were not large and should not endanger pole users. We compared several test methods including the Pilodyn, radial compression tests, longitudinal compression tests, and the pick test for evaluating residual pole strength of the wood surface of Douglas-fir treated with combinations of funtigants or groundline wraps. The results indicate that only the pick test could accurately detect surface damage and illustrate the difficulty of detecting surface damage. This past year we evaluated several sections cut from ACA treated poles stored for a number of years to determine if they were worth salvaging. Static bending tests of beams cut from the ACA treated zone, the treated/untreated boundary, and the inner heartwood revealed ACA treated sapwood had lower MOR and longitudinal compression strength than the other zones. These results represent only a small sample, but they suggest that some strength loss occurs during ACA V treatments. More importantly, the results suggest that we could have reliably predicted beam MOR by testing small plugs removed from the poles. Small beams cut from decaying, pentachlorophenol treated Douglas-fir poles were acoustically tested for residual wood strength, then evaluated to failure in static bending. The acoustic test consisted of sending a pulsed sonic wave into the wood and recording this wave after it passed through the beam. As it moved, the wave was altered by the presence of any wood defects or decay, and these alterations create a "fingerprint" specific for that defect. Preliminary results indicated that signal analysis was highly 2 2 correlated with work to maximum load (r =.82) and MOR (r .88), suggesting that this approach to decay detection may prove more reliable than measuring of sound velocity. Initiation of Decay in Air-Seasoning Douglas-fir The results of the initial survey to determine the incidence of decay fungi in poles from widely scattered Pacific Northwest seasoning yards indicated that a variety of fungi were colonizing the wood. While most of these fungi do not pose a serious decay problem, two species, Poria carbonica and Poria placenta, became increasingly abundant with length of air-seasoning. These fungi are also the most conunon decayers of Douglas-fir poles in service. As expected, the number of fungi and the wood volume they occupied increased with seasoning time; however, this incidence varied considerably between yards, especially in poles air-seasoned for vi shorter time periods. In addition to the variation between sites, many of the decay fungi colonizing the wood appear to be monokaryons, indicating that spores landing on the wood are initiating the infestation. The distribution of fungi within the poles indicated that several of the more abundant decay fungi were present in the outer sapwood where they would be eliminated by conventional pressure treatment. The remaining fungi were most abundant in the heartwood but were more concentrated near the pole end. This suggests that exposed end grain was more readily invaded than lateral grain exposed in checks. In addition to identifying the fungi colonizing Douglas-fir, we examined the effects these fungi had on wood strength. Toughness tests indicated the presence of wide variation in decay capability of the isolates. Although there was no consistent pattern, most of the isolates did not cause substantial decay and, of those that did, only . carbonica and P. placenta were sufficiently abundant to have a large influence on wood strength. Due to the prevalence of P. carbonica and P. placenta in the inner heartwood, where they might not be eliminated in a short heating cycle, we evaluated the temperature tolerance of these two fungi in Douglas-fir heartwood blocks. These tests indicated that both fungi were eliminated by exposure to temperatures above 71°C for over 1 hour or 60°C for 2 hours. The results suggest that careful control of temperature during treatment should eliminate decay fungi and that wood treated at ambient temperatures should be heated to kill fungi that become established during air-seasoning. vii This past year was the third and final year of the decay development study. In this study, sterile pole sections have been exposed for 1, 2, or 3 years at widely scattered Pacific Northwest sites, then returned to the laboratory and extensively sampled. We are now in the process of identifying the fungi from the third year poles. In addition to examining poles prior to preservative treatment, we are also evaluating poles treated with waterborne chemicals (ACA or CCA) for the incidence of surface decay. This past year we examined twenty ACA-treated poles from a line installed in 1946. While a variety of fungi were cultured from the wood, none of the poles had evidence of substantial surface deterioration. A study was initiated on the fungal flora of fumigant treated wood because of the potential for fungi developing resistance to low levels of fumigant or the ability to actively degrade the chemical. Both of these developments could shorten fumigant retreatment cycles and increase maintenance costs. We have evaluated poles treated 7 and 15 years ago with fumigants and find markedly reduced fungal flora. Tests are continuing on the fungi isolated, and we hope to assess the effects of these isolates on long-term fumigant effectiveness. Close