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• 1. [Article] Wood Pole Maintenance Manual: 2012 Edition

  Morrell, Jeffrey J. 2012. Wood Pole Maintenance Manual: 2012 Edition. Research Contribution 51, Forest Research Laboratory, Oregon State University, Corvallis. The specification, inspection, ...

  Citation × Citation Citation Abstract Copy Title: Wood Pole Maintenance Manual: 2012 Edition Author: Morrell, Jeffrey J. Morrell, Jeffrey J. 2012. Wood Pole Maintenance Manual: 2012 Edition. Research Contribution 51, Forest Research Laboratory, Oregon State University, Corvallis. 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. Title: Wood Pole Maintenance Manual: 2012 Edition Author: Morrell, Jeffrey J. Morrell, Jeffrey J. 2012. Wood Pole Maintenance Manual: 2012 Edition. Research Contribution 51, Forest Research Laboratory, Oregon State University, Corvallis. 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. Close

• 2. [Article] Decomposition of metham sodium to methylisothiocyanate as affected by wood species, temperature, and moisture content

  The effect of various wood characteristics on decomposition of metham sodium to methylisothiocyanate in sixteen North American and Southeast Asian hardwoods and softwoods was investigated. While marked ...

  Citation × Citation Citation Abstract Copy Title: Decomposition of metham sodium to methylisothiocyanate as affected by wood species, temperature, and moisture content Author: Morrell, Jeffrey J. The effect of various wood characteristics on decomposition of metham sodium to methylisothiocyanate in sixteen North American and Southeast Asian hardwoods and softwoods was investigated. While marked differences were noted in the degree of decomposition among some species, the relationship between decomposition and lignin content, extractive levels, wood pH, or I0/o alkali solubility was slight within the various species. Wood moisture content had the greatest influence on decomposition, while temperature had a lesser effect. The results suggest that the wood environment could be manipulated to enhance metham sodium decomposition, thereby allowing dosage to be reduced or the period between applications to be prolonged. Title: Decomposition of metham sodium to methylisothiocyanate as affected by wood species, temperature, and moisture content Author: Morrell, Jeffrey J. The effect of various wood characteristics on decomposition of metham sodium to methylisothiocyanate in sixteen North American and Southeast Asian hardwoods and softwoods was investigated. While marked differences were noted in the degree of decomposition among some species, the relationship between decomposition and lignin content, extractive levels, wood pH, or I0/o alkali solubility was slight within the various species. Wood moisture content had the greatest influence on decomposition, while temperature had a lesser effect. The results suggest that the wood environment could be manipulated to enhance metham sodium decomposition, thereby allowing dosage to be reduced or the period between applications to be prolonged. Close

• 3. [Article] Controlling decay fungi in Douglas-fir heartwood with pelletized sodium n-methyldithiocarbamate

  A small block test was used in assessing whether pelletized sodium n-methyldithiocarbamate (NaMDC) would decompose and produce methylisothiocyanate (MITC) and thereby eliminate Antrodia carbonica colonies ...

  Citation × Citation Citation Abstract Copy Title: Controlling decay fungi in Douglas-fir heartwood with pelletized sodium n-methyldithiocarbamate Author: Sexton, Camille M., Morrell, Jeffrey J., Newbill, Mark A. A small block test was used in assessing whether pelletized sodium n-methyldithiocarbamate (NaMDC) would decompose and produce methylisothiocyanate (MITC) and thereby eliminate Antrodia carbonica colonies from Douglas-fir heartwood. Also evaluated were the effects of wood moisture content, dosage, incubation period, pH level, and presence of copper sulfate on percentage of kill of the fungus and amount of MITC in the wood. Increasing moisture content produced the most dramatic increases in MITC production and fungal control. The effects of pH and the presence of copper ions were more variable. The results indicate that pelletized NaMDC can effectively control fungal infestations in Douglas-fir heartwood. Field studies are planned. Title: Controlling decay fungi in Douglas-fir heartwood with pelletized sodium n-methyldithiocarbamate Author: Sexton, Camille M., Morrell, Jeffrey J., Newbill, Mark A. A small block test was used in assessing whether pelletized sodium n-methyldithiocarbamate (NaMDC) would decompose and produce methylisothiocyanate (MITC) and thereby eliminate Antrodia carbonica colonies from Douglas-fir heartwood. Also evaluated were the effects of wood moisture content, dosage, incubation period, pH level, and presence of copper sulfate on percentage of kill of the fungus and amount of MITC in the wood. Increasing moisture content produced the most dramatic increases in MITC production and fungal control. The effects of pH and the presence of copper ions were more variable. The results indicate that pelletized NaMDC can effectively control fungal infestations in Douglas-fir heartwood. Field studies are planned. Close

• 4. [Article] Methylisothiocyanate fumigant content of Douglas-fir heartwood at various moisture levels after treatment with solid sodium N-methyldithiocarbamate

  The relationship between moisture content and the presence of methylisothiocyanate (MITC) in wood following various applications of sodium n-methyldithiocarbamate (NaMDC) was investigated with small Douglas-fir ...

  Citation × Citation Citation Abstract Copy Title: Methylisothiocyanate fumigant content of Douglas-fir heartwood at various moisture levels after treatment with solid sodium N-methyldithiocarbamate Author: Lebow, Stan T., Morrell, Jeffrey J. The relationship between moisture content and the presence of methylisothiocyanate (MITC) in wood following various applications of sodium n-methyldithiocarbamate (NaMDC) was investigated with small Douglas-fir heartwood blocks. While MITC levels were initially higher in wetter blocks, MITC levels in drier blocks remained more stable over the 8-week test period. The addition of water as well as NaMDC to blocks enhanced MITC levels only initially; this effect declined over the test period for blocks at 30% MC or greater. In comparing the effect on MITC levels of applying the NaMDC in powder or pellet form, no significant difference between the two application methods emerged. Title: Methylisothiocyanate fumigant content of Douglas-fir heartwood at various moisture levels after treatment with solid sodium N-methyldithiocarbamate Author: Lebow, Stan T., Morrell, Jeffrey J. The relationship between moisture content and the presence of methylisothiocyanate (MITC) in wood following various applications of sodium n-methyldithiocarbamate (NaMDC) was investigated with small Douglas-fir heartwood blocks. While MITC levels were initially higher in wetter blocks, MITC levels in drier blocks remained more stable over the 8-week test period. The addition of water as well as NaMDC to blocks enhanced MITC levels only initially; this effect declined over the test period for blocks at 30% MC or greater. In comparing the effect on MITC levels of applying the NaMDC in powder or pellet form, no significant difference between the two application methods emerged. Close

• 5. [Article] The effect of pH on decomposition of Mylone (dazomet) and tridipam to fungitoxic methylisothiocyanate in wood

  Mylone@ and tridipam are two solid chemicals that decompose to produce methylisothiocyanate (MIT), a highly effective wood fumigant. In this study, two techniques -- a rapid, test-tube method and small-scale, ...

  Citation × Citation Citation Abstract Copy Title: The effect of pH on decomposition of Mylone (dazomet) and tridipam to fungitoxic methylisothiocyanate in wood Author: Lebow, Stan, Morrell, Jeffrey J., Sexton, Camille M. Mylone@ and tridipam are two solid chemicals that decompose to produce methylisothiocyanate (MIT), a highly effective wood fumigant. In this study, two techniques -- a rapid, test-tube method and small-scale, wood-block assay -- were used to determine the effect of the pH of various chemical buffers on the decomposition of Mylone@ and tridipam in Douglas-fir heartwood samples colonized by Poria carbonica. Both chemicals were sensitive to pH, and higher levels of MIT were produced as the pH of the buffers increased. In general, fungal survival was not affected 1 week after chemical treatment. Complete control of P. carbonica, however, resulted after 4 weeks of exposure to 50 mg Mylone@/block or 150 mg tridipam/block, when each chemical was combined with a pH-12 buffer. These results suggest that regulating fumigant treatments according to the degree of fungal attack can substantially improve the precision of decay control in wood maintenance programs. Title: The effect of pH on decomposition of Mylone (dazomet) and tridipam to fungitoxic methylisothiocyanate in wood Author: Lebow, Stan, Morrell, Jeffrey J., Sexton, Camille M. Mylone@ and tridipam are two solid chemicals that decompose to produce methylisothiocyanate (MIT), a highly effective wood fumigant. In this study, two techniques -- a rapid, test-tube method and small-scale, wood-block assay -- were used to determine the effect of the pH of various chemical buffers on the decomposition of Mylone@ and tridipam in Douglas-fir heartwood samples colonized by Poria carbonica. Both chemicals were sensitive to pH, and higher levels of MIT were produced as the pH of the buffers increased. In general, fungal survival was not affected 1 week after chemical treatment. Complete control of P. carbonica, however, resulted after 4 weeks of exposure to 50 mg Mylone@/block or 150 mg tridipam/block, when each chemical was combined with a pH-12 buffer. These results suggest that regulating fumigant treatments according to the degree of fungal attack can substantially improve the precision of decay control in wood maintenance programs. Close

• 6. [Article] Decomposition of Basamid in Douglas-fir heartwood: Laboratory studies of a potential wood fumigant

  Basamid (3,5-dimethyl-l,3,5,2H-tetrahydrothiadiazine-2-thione), a crystalline powder first used as a soil sterilant, has shown promise as a wood fumigant. This chemical decomposes to methylisothiocyanate ...

  Citation × Citation Citation Abstract Copy Title: Decomposition of Basamid in Douglas-fir heartwood: Laboratory studies of a potential wood fumigant Author: Forsyth, Paul G., Morrell, Jeffrey J. Basamid (3,5-dimethyl-l,3,5,2H-tetrahydrothiadiazine-2-thione), a crystalline powder first used as a soil sterilant, has shown promise as a wood fumigant. This chemical decomposes to methylisothiocyanate (MITC), the primary active ingredient, as well as other products; but the rate of decomposition in wood is too slow to be effective unless certain catalysts are used. This study explored conditions and additives that accelerated Basamid decomposition in Douglas-fir heartwood. MITC production increased with increasing temperature and moisture content. Decomposition was also enhanced by a buffer powder formulated to reach pH 12 when mixed with 100 ml of water and, more efficiently, by copper sulfate. Carbon disulfide, a less fungitoxic compound, was the only other decomposition product detected in this study. Additional tests using a purge-and-trap system indicated that MITC was produced at a steady, moderate rate over a 28-day period. Addition of copper as a catalyst in these tests increased MITC production only during the first 7 days. Chemical analyses of residues at the conclusion of the tests indicated that most of the Basamid remained unchanged, providing a reservoir of chemical that should provide long-term MITC release. Title: Decomposition of Basamid in Douglas-fir heartwood: Laboratory studies of a potential wood fumigant Author: Forsyth, Paul G., Morrell, Jeffrey J. Basamid (3,5-dimethyl-l,3,5,2H-tetrahydrothiadiazine-2-thione), a crystalline powder first used as a soil sterilant, has shown promise as a wood fumigant. This chemical decomposes to methylisothiocyanate (MITC), the primary active ingredient, as well as other products; but the rate of decomposition in wood is too slow to be effective unless certain catalysts are used. This study explored conditions and additives that accelerated Basamid decomposition in Douglas-fir heartwood. MITC production increased with increasing temperature and moisture content. Decomposition was also enhanced by a buffer powder formulated to reach pH 12 when mixed with 100 ml of water and, more efficiently, by copper sulfate. Carbon disulfide, a less fungitoxic compound, was the only other decomposition product detected in this study. Additional tests using a purge-and-trap system indicated that MITC was produced at a steady, moderate rate over a 28-day period. Addition of copper as a catalyst in these tests increased MITC production only during the first 7 days. Chemical analyses of residues at the conclusion of the tests indicated that most of the Basamid remained unchanged, providing a reservoir of chemical that should provide long-term MITC release. Close

• 7. [Article] Evaluating potential decay control agents with a small block test

  A small-scale test was developed to evaluate the ability of fungicides to control decay fungi established in wood. The test, which uses blocks 2.5 x 2.5 x 10 cm, tests the ability of a chemical to migrate ...

  Citation × Citation Citation Abstract Copy Title: Evaluating potential decay control agents with a small block test Author: Morrell, Jeffrey J., Corden, Malcolm E. A small-scale test was developed to evaluate the ability of fungicides to control decay fungi established in wood. The test, which uses blocks 2.5 x 2.5 x 10 cm, tests the ability of a chemical to migrate from the middle of the block to control a previously established decay fungus, Poria carbonica. The effect of block size, degree of fungal development, chemical exposure period, and aeration during exposure were evaluated on chemicals previously shown to be effective for remedial control of decay. The method was then used to evaluate potential decay control chemicals. Highly volatile chemicals proved to be most effective, while water-soluble and oil-borne chemicals produced much poorer control. The small block tests appear to provide a simple, rapid, and accurate method for predicting how chemicals will control established decay fungi in wood. Title: Evaluating potential decay control agents with a small block test Author: Morrell, Jeffrey J., Corden, Malcolm E. A small-scale test was developed to evaluate the ability of fungicides to control decay fungi established in wood. The test, which uses blocks 2.5 x 2.5 x 10 cm, tests the ability of a chemical to migrate from the middle of the block to control a previously established decay fungus, Poria carbonica. The effect of block size, degree of fungal development, chemical exposure period, and aeration during exposure were evaluated on chemicals previously shown to be effective for remedial control of decay. The method was then used to evaluate potential decay control chemicals. Highly volatile chemicals proved to be most effective, while water-soluble and oil-borne chemicals produced much poorer control. The small block tests appear to provide a simple, rapid, and accurate method for predicting how chemicals will control established decay fungi in wood. Close

• 8. [Article] Diffusion and sorption of the fumigant methylisothiocyanate in Douglas-fir wood

  The influence of moisture content (MC) and conventional preservative treatment on methylisothiocyanate (MIT) sorption and diffusion were investigated in Douglas-fir wood. In wood at 0% MC, the ratio of ...

  Citation × Citation Citation Abstract Copy Title: Diffusion and sorption of the fumigant methylisothiocyanate in Douglas-fir wood Author: Morrell, Jeffrey J., Zahora, Andrew R. The influence of moisture content (MC) and conventional preservative treatment on methylisothiocyanate (MIT) sorption and diffusion were investigated in Douglas-fir wood. In wood at 0% MC, the ratio of equilibrium MIT adsorption to desorption concentrations was low (0.2), but it increased rapidly to about 0.94 above 18% MC. Partition coefficients (bound/vapor MIT) for MIT adsorption to wood increased with wood moisture from 0% to about 12%. At higher moisture contents, sorbed water apparently interfered with MIT sorption, and partition coefficients decreased with wood moisture content for both MIT adsorption and desorption. Steady-state diffusion coefficients were dependent on wood moisture content, but were at least 200 times higher for longitudinal movement of MIT in Douglas-fir heartwood than for transverse movement. Diffusion coefficients increased with wood moisture content below the fiber-saturation point, apparently as a result of improved bound MIT diffusion. Increasing wood moisture content from 22% to 80% reduced longitudinal MIT diffusion almost threefold, but did not greatly influence tangential MIT diffusion. Radial movement of MIT was about seven times faster in Douglas-fir sapwood than in heartwood. Preservative treatment with waterborne chromated copper arsenate did not influence MIT sorption or diffusion in sapwood at 15% MC, but impregnation with P-9 Type A oil restricted MIT movement and may provide a barrier to fumigant loss. Title: Diffusion and sorption of the fumigant methylisothiocyanate in Douglas-fir wood Author: Morrell, Jeffrey J., Zahora, Andrew R. The influence of moisture content (MC) and conventional preservative treatment on methylisothiocyanate (MIT) sorption and diffusion were investigated in Douglas-fir wood. In wood at 0% MC, the ratio of equilibrium MIT adsorption to desorption concentrations was low (0.2), but it increased rapidly to about 0.94 above 18% MC. Partition coefficients (bound/vapor MIT) for MIT adsorption to wood increased with wood moisture from 0% to about 12%. At higher moisture contents, sorbed water apparently interfered with MIT sorption, and partition coefficients decreased with wood moisture content for both MIT adsorption and desorption. Steady-state diffusion coefficients were dependent on wood moisture content, but were at least 200 times higher for longitudinal movement of MIT in Douglas-fir heartwood than for transverse movement. Diffusion coefficients increased with wood moisture content below the fiber-saturation point, apparently as a result of improved bound MIT diffusion. Increasing wood moisture content from 22% to 80% reduced longitudinal MIT diffusion almost threefold, but did not greatly influence tangential MIT diffusion. Radial movement of MIT was about seven times faster in Douglas-fir sapwood than in heartwood. Preservative treatment with waterborne chromated copper arsenate did not influence MIT sorption or diffusion in sapwood at 15% MC, but impregnation with P-9 Type A oil restricted MIT movement and may provide a barrier to fumigant loss. Close