Search
Search Results
-
1. [Article] Wood pole maintenance manual
The specification, inspection, and remedial treatment of utility poles are addressed. Included are discussions of enhancing specifications for improved performance, techniques for detecting decay and other ...Citation Citation
- Title:
- Wood pole maintenance manual
- Author:
- Morrell, Jeffrey J., Oregon State University. Forest Research Laboratory
The specification, inspection, and remedial treatment of utility poles are addressed. Included are discussions of enhancing specifications for improved performance, techniques for detecting decay and other defects, and chemical treatments available for arresting decay of poles in service.
-
-
-
-
-
Previously established field trials of MTTC-Fume continue to show that this chemical remains in Douglas-fir and southern pine poles at fungitoxic levels 5 years after treatment. In general, increasing ...
Citation Citation
- Title:
- Conserving energy by environmentally acceptable practices in maintaining and procuring transmission poles for long service ; September 1995
- Author:
- Morrell, Jeffrey J., Oregon State University. Dept. of Forest Products, Corden, M. E. (Malcolm E.)
Previously established field trials of MTTC-Fume continue to show that this chemical remains in Douglas-fir and southern pine poles at fungitoxic levels 5 years after treatment. In general, increasing dosages resulted in higher chemical levels in the poles. All of the MITC-Fume treatments resulted in higher residual M1TC levels than comparable metham sodium treatments. Field trials with solid basaniid with and without copper sulfate continue to show the promise of this chemical. Basamid treated poles continue to contain MITC at levels which exceed those for comparable metham sodium treatments. These results, which are currently being confirmed in poles in service, indicate that this formulation can deliver fiingitoxic MITC levels to wood in service, without the risk of spills associated with metham sodium. We have completed trials with gelled and pelletized metham sodium formulations. Both of these formulations offered improved safety during application. Initial laboratory trials also suggested that the gelled formulation was more effective than comparable liquid metham sodium. Field trials, however, indicate that the formulations provided protection comparable to the liquid formulation in poles over the test period. The gelled formulation still offers the advantage of reduced risks of spills during application. Trials are also continuing with various solid, water diffusible treatments for arresting internal decay. Trials of fused borate rods continue to show that these treatments require more moisture for effective movement in Douglas-fir poles. Field trials have also been established with borate rods with glycol as an additive to determine if glycols can accelerate diffusion in drier wood. The poles in these trials have also been sensored to monitor internal moisture changes over time in order to better correlate boron diffusion with wood moisture content. Trials underway with a boronlfluoride rod indicate that the boron is diffusing well from these rods, while the fluoride is moving somewhat slower. Neither chemical has approached a fiungal threshold one year after treatment, but the combination of chemicals may lead to more effective fungal control. Trials with pelletized metham sodium/basamid mixtures suggests that using ratios of these two chemicals can produce an initial rapid burst ofMITC release followed by a slower MITC release with time. This combination allows for rapid control of existing fungal infestations followed by long term protection against reinvasion. These laboratory trials will be further confirmed with field trials. The trials to evaluate the effects of voids on fumigant movement initially suggested that voids have little influence on subsequent fumigant levels on either side of the void. Sampling 8 years after treatment, however, indicates that chioropicrin levels were generally higher in poles without voids. We plan further trials of actual field poles containing voids to confirm these effects. Trials to identify treatments for protecting the sapwood of western redcedar poles as well as wood exposed in field drilled bolt holes are continuing. Trials in western redcedar sapwood have identified a number of chemicals which can be remedially applied to protect this wood against fungal attack. At present, however, commercial pole spraying has largely ceased making further field trials difficult. Field trials to identify treatments for protecting untreated wood exposed during drilling for various pole attachments continue to show that diffusible boron and fluoride compounds provide excellent long term protection against flingal attack. The protective effects of one diffusible treatment, Boracol, however, has begun to decline. Further sampling will be undertaken to identify the long term effectiveness of the remaining treatments. Trials to identify enhanced patterns for through boring of Douglas-fir poles are complete. The results indicate that patterns as widely spaced as 400 mm apart longitudinally still produce a nearly completely treated pole i n the through bored zone. Pentachlorophenol levels in the through bored zone were generally above the threshold for ftrngal growth. Prior sampling of Douglas-fir poles in service suggest that even poles with small skips in the through bored zone contained no evidence of internal decay. These results suggest that the through boring pattern can be extended without adversely risking pole service life. A reduced through boring pattern would decrease treatment costs while minimizing impacts on pole strength. Trials to evaluate the application of boron to freshly peeled Douglas-fir poles as a means of preventing fungal colonization using a thermal process suggest that thermal treatment failed to produce a boron loading sufilcient to permit subsequent diffusion across the pole section after a 3 month diffusion period. Evaluations of various external groundline preservative formulations continue to indicate that replacement formulations based upon copper naphthenate, boron or fluoride perform comparably to earlier formulations employing pentachlorophenol and creosote. Pentachlorophenol levels in some treatments have fallen below the threshold for fungal growth, while those in all of the replacement treatments remain above a U protective level. These results suggest that the newer groundline preservative systems should provide a reasonable level of protection against external decay. Laboratory trials to better understand the levels of combinations of chemicals required for protection in the groundline zone are continuing. Fungal cellar evaluations of copper naphthenate treated western redcedar continue to show excellent performance at levels specified in the American Wood Preservers' Association Standards. Performance is generally better for wood which was freshly sawn prior to treatment, while wood cuts from weathered poles in service has provided slightly lower levels of protection. The weather wood apparently has higher permeability, making it more likely to lose chemical in soil contact. Further evaluations are planned.
-
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
- 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.
-
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
- 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.
-
The eighth annual report details continued progress on each of the five objectives. In this year's report, Objectives II and III from previous reports have been combined to reflect the similarity of each ...
Citation Citation
- Title:
- Conserving energy by environmentally acceptable practices in maintaining and procuring transmission poles for long service ; August 1988
- Author:
- Morrell, Jeffrey J., Corden, M. E. (Malcolm E.)
The eighth annual report details continued progress on each of the five objectives. In this year's report, Objectives II and III from previous reports have been combined to reflect the similarity of each effort. Improved fumigants: The previously established field trials continue to demonstrate the superior performance of both chioropicrin and Vorlex after 18 years in poles and 13 years in piling. In addition, solid methylisothiocyanate (MIT) continues to protect Douglas-fir poles in a manner similar to Vorlex. Along with evaluations of existing registered formulations, we continue to explore the use of novel solid fumigants for their ability to arrest decay in Douglas-fir heartwood. Laboratory studies indicate that both Mylone and sodium n-methyldithiocarbamate (NaMDC) can be pelletized to improve handling safety. Previous studies indicate that the rate of decomposition to produce MIT is often too slow for effective fungal control, but the incorporation of certain buffers or metallic salts can alter the rate and characteristics of chemical decomposition. In our tests, the levels of chemical release varied with PH; however, complete fungal control was not achieved. Further studies are underway to determine if other conditions can alter the rate of MIT production by these compounds. Both chemicals are registered for other, nonfood uses and should be registerable for application to wood. Efforts to better understand the properties of MIT, the major fungitoxic product of both Vorlex and Vapam, are also continuing. These efforts have led to the development of a preliminary model to describe fumigant movement through Douglas-fir heartwood. The goal of this work is optimize treatment dosage and application patterns for various pole sizes. In addition to the more theoretical studies, we are continuing our efforts to determine the ability of fumigants to control decay fungi in poles containing large decay voids and to determine the levels of volatile emissions from fumigant treated wood. Field treatment: The field tests to evaluate potential replacements for pentachlorophenol (penta) treatment of western redcedar sapwood were evaluated after 7 years using the Aspergillus bioassay. The results indicate that residual levels of chemical were detectable in the penta treatments, but the remaining test chemicals exhibited little evidence of residual fungitoxicity. Further decay tests are planned on material removed from these pole sections. In addition to the pole sections, the small-scale test blocks were also evaluated using the Aspergillus bioassay. The results indicate that several chemicals remained in the wood at fungitoxic levels after one year of accelerated weathering. Further decay tests are also planned on these samples. The bolt hole study is now in its seventh year and the incidence of decay fungi in the test poles remains low. Variations in incidence from year to year have made it difficult to draw any useful conclusions from this study. To overcome this problem, a second test has been established which accelerates leaching and evaluates the ability of a test fungus to invade the field drilled bolt hole to cause wood weight loss. Decay detection and residual strength: We continue to evaluate the use of lectins for detecting fungal colonization at the early stages. This past year, we completed a comparison of colonization by three common decay fungi over a 12 week period. The search for small-scale methods for estimating residual strength is also continuing. Longitudinal compression measurements were used to determine residual strength of a pole involved in an automobile accident. ii Finally, we have completed portions of a study to determine the effects of fungal colonization on wood strength. Four fungi, Poria carbonica, Poria placenta, Peniophora spp., and Haematostereum sanguinolentum were evaluated in this study. Results with P. carbonica and Peniophora spp. indicate strength effects lag behind fungal colony development in small beams. These results were similar to previous field studies and indicate that air-seasoning for 2 to 3 years should not produce significant strength losses. Further studies with these fungi are underway. Initiation of decay in air-seasoning Douglas-fir: While the air-seasoning studies are now completed, we are continuing to evaluate the data from these tests. A detailed examination of the three year decay development study indicates that several fungi were typically found only in the heartwood or sapwood zones of the pole sections. In addition, the fungal flora at the four seasoning sites varied widely, with the greatest deviation occurring at the Oroville, CA. This site has the driest and warmest conditions, and would appear to be best site for seasoning. A detailed discussion of isolation frequency by position is presented for the eleven most common basidiomycetes. Studies to prevent colonization by basidiomycetes during air-seasoning are also continuing using polyborate dips or sprays. Sodium octaborate tetrahydrate appears to reduce the level of colonization after one year of air-seasoning at both Oroville and Corvallis, OR. Dipping shortly after peeling appeared to produce the best results, although spraying at regular intervals also had some effect on colonization. This study will continue for an additional two years. Determining the ability of existing pressure treatment cycles to eliminate fungi which colonize Douglas-fir poles during air-seasoning also remains a high priority. Only a few additional schedules were examined during iv the past year, but efforts to develop more realistic heating curves are under way. In addition, several questions concerning the accuracy of the existing data were answered. Additional studies using the Cellon process and the longer steaming period for the ammoniacal copper zinc arsenate treatments are planned in the coming year. While sterilization during preservative treatment is an important factor in pole longevity, questions have also arisen concerning the storage of poles for long periods after treatment. A survey of poles which were treated with creosote, pentachiorophenol, chromated copper arsenate, and ammoniacal copper arsenate prior to storage for one to 15 years was conducted. While colonization varied widely between sites, the results indicated that storage of poles for long periods substantially increased the risk that the pole would be placed in service with an active decay fungus established somewhere along its length. Several suggestions are made for remedying this situation. Effect of microfunqi on Douglas-fir poles: A study was conducted to determine the effect of microfungi which commonly colonize fumigant treated Douglas-fir heartwood on the ability of P. carbonica and P. placenta to cause wood weight loss in fumigant treated wood. The results indicate that several isolates were associated with reduced weight losses by these fungi. The decreased weight losses suggest that the microfungi could be colonizing fumigant treated poles prior to the basidiomycetes and, once there, could help prevent reinvasion. This scheme may help explain the remarkable protection provided by fumigant treatment. Further studies are underway to explore this possibility.
-
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
- 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.