Your search resulted in 27 documents. Displaying 25 entries per page.
Blue-stain fungi (Ceratocystis spp.) found in Spain on pine woods
1989 - IRG/WP 1410
So far, there is only a very limited reported description of the different Ceratocystis spp. present on fresh wood in Spain. So, the main goal of this work has been the identification of species of this genus causing blue-stain on Pinus pinaster A. Ait. and Pinus sylvestris L. woods. We have also investigated the relationship between the species found and their propagation vectors (insects and wind). Finally, we have determined the growing velocity of two of the most representative species found and the presence or absence of degradative enzymatic activities.
M T De Troya, A M Navarrete
Laboratory screening to determine the preventive effectiveness against blue stain fungi and moulds
1991 - IRG/WP 3677
This paper reports results of preservative treatment and leaching experiments, using borax, polybor and boracol 20, on small wood blocks of English oak and American pitch pine heartwood. Earlier experiments on the performance of various biocides as possible additives to bilgewater to prevent fungal decay of shipping timbers had suggested that some formulations of boron might be associated with physical changes to specific types of timber. Since samples of oak and pitch pine were to be supplied for remedial work on the historic ship RRS Discovery it became important to investigate more critically the effects of boron on such timbers. Variable factors investigated in this study included temperature, sample type, soaking time in preservative and time of leaching. Weight changes and dimensional changes were measured. Preliminary results indicate that there was little effect, at 10°C, on block weight or dimension. Some changes were found at 45°C indicating that the results obtained in earlier experiments may be unrepresentative of those which might be obtained when the biocide is used under service conditions.
M T De Troya, A M Navarrete
Comparison between two laboratory test methods for determining the effectiveness on wood preservatives against blue stain in fresh wood
1987 - IRG/WP 2289
Most of the work done on determination of the effectiveness of new formulae for treating fresh wood against blue stain have been focussed on their use in the manufacture of saw timber. This work explains two laboratory methods, one which simulates the working and climatological conditions of factories making packages for fruit and vegetables in the Spanish Levante, showing that contamination of wood is caused naturally, and another method causing blue stain by innoculation with pure cultures. Both methods were applied to eight preservatives, and the results were compared.
A M Navarrete, M T De Troya
Analysis of the degradation of carbohydrates by blue-stain fungi
1990 - IRG/WP 1457
The topic of the degradative ability of blue-stain fungi literature is not clear. Many authors support the idea that those fungi don't have enzymatic capability to decay the wall of the ligneous cells. However, others have found some decay activity. In this study, we have attempted to analyze which wall cells soluble carbohydrates are metabolized by some blue-stain fungi, found in Spain. The tested fungi have been: Pullularia pullulans and Sclerophoma pityophila (wind-dispersed), and Ceratocystis huntii and Ceratocystis ips (bark beetles transmitted). This study has been realized through the determination of: the growing rate, the amount of biomass produced by these fungi and the chemical analysis of the culture media, with six different carbohydrates (glucose, mannose, rhamnose, arabinose, galactose and xylose).
M T De Troya, A M Navarrete, E Relano
Characterisation of growth and stain of different groups of sapstain fungi on lodgepole pine
1999 - IRG/WP 99-10326
Canada is the world's largest exporter of softwood lumber. These softwood shipments are susceptible to a variety of wood-inhabiting fungi that can lead to sapstain discolouration, which in turn decrease the product value. Furthermore, the presence of these microorganisms may be unacceptable to the importing countries. The objective of this work is to assess the sapstaining capability and basic nutrition of thirty-four fungi isolates representing nine species that were isolated from sawmills across western Canada. The isolates were infected onto fresh lodgepole pine billets and assessed for staining ability, longitudinal growth, host-nutrient consumption, and host viability. The results indicated that the most aggressive saptain species on fresh logs was Ceratocystis coerulescens, followed consecutively by Leptographium spp, Ophiostoma minus, O. piliferum, O. piceae, Ophiostoma spp (D and E) and Aureobasidium pullulans. Preliminary HPLC analysis of soluble sugars indicated that mannose was the free monomer carbohydrate of choice for most of the staining fungi, followed by glucose. Arabinose and galactose were not well utilised. Gas chromatography of infected wood extracts that Leptographium sp. and C. coerulescens significantly reduced the triglyceride fraction.
C Fleet, C Breuil, A Uzunovic, A Byrne
Detection of semi-quantitative and qualitative enzymatic activities of blue-stain fungi
2000 - IRG/WP 00-10347
Blue-stain, produced in forests, continues to be a problem in countries of moderate climate. In forestry, in certain geographical areas of Spain, it has been observed that anti-sapstain products have not always been efficient, as their fungicidal effectiveness varies on occasion, depending on the species of wood and microbiota that exist in the region. It is not always easy to identify the species causing this damage. Therefore, the object of this study was the grouping of diverse isolates according to the detection of simple enzymatic activities, following a simple and rapid method of application such as API-ZYM. 36 strains of Ceratocystis spp, isolated from divers species of Pinus spp., have been tested. The results were contrasted with the activities detected in the same conditions in Pullularia pullulans and Sclerophoma pityophila. To do this, these strains were inoculated in culture broths with a basic saline Eggins and Pugh medium, to which 1% sawdust of Pinus sylvestris was added in one trial. Another test was made with a mixture of the most frequent monosaccharides in woody cell-walls (glucose, mannose, galactose, arabinose, and xylose) at 1%. After 20 days of incubation, the extracts were centrifuged, and inoculated in microtubes series of API-ZYM. The analysis of the principal components, carried out with the results obtained, showed that the sawdust induces enzymatic activities implicated in the degradation of polysaccharides such as in a-mannosidase, a-galactosidase, b-glucuronidase, b-glucosidase and b-galactosidase, which appeared as the most weighty specific factors in the dispersion of data on the first two principal axes. Different strains of Ceratocystis also showed similar or greater activity than those of P. pullulans and S. pityophila, which suggests that the latter might be more virulent than the rest of the strains assayed.
M T De Troya, F Llinares, D Muñoz-Mingarro, M J Pozuelo, N Acero, C Rodríguez-Borrajo, A M Navarrete
Laboratory fumigations to determine the minimum temperature for methyl bromide eradication of the oak wilt fungus in red oak
1983 - IRG/WP 3243
Laboratory chamber fumigations of naturally-infected ret oak log sections exterminatet the oak wilt fungus in sapwood at temperatures down to 0°C. Only low, sporadic fungus survival was observed when log sections were gassed with methyl bromide at -5°C and aired for 4 da. at 0°C. Lower temperature treatments were not effective even if gas levels or exposure times were increased by 50%.
E L Schmidt
The use of chlorothalonil for protection against mold and sapstain fungi. Part 1: Laboratory evaluation
1989 - IRG/WP 3515
Laboratory screening of chlorothalonil alone and in combination with other fungicides was conducted against six mold and sapstain fungi. The most promising treatments appear to be chlorothalonil supplemented with CCA or copper-8-quinolinolate. Field tests have been implemented.
J A Micales, T L Highley, A L Richter
Methyl bromide eradication of the oak wilt fungus in logs. Laboratory and field fumigation
1981 - IRG/WP 3168
Concern over accidental introduction of the oak wilt fungus (Ceratocystis fagacearum) into oak-importing nations has prompted a study supported by the U.S. National Lumber Exporter's Assn. to assess the efficacy of methyl bromide fumigation to eradicate the fungus from logs and lumber. Laboratory and field fumigation trials to develop a reliable and realistic treatment were performed on red and white oaks at the University of Minnesota in 1980. Introduction of pure methyl bromide at a rate of 240 g/m³ of space under a polyethylene cover kept in place for 3 days eradicated the fungus from short log sections at temperatures down to 5°C in laboratory chamber fumigations. Outdoor trials using 2.4 m logs with intact bark reduced the fungus isolation frequency to a fractional percentage of untreated controls, but reducing the duration of fumigation to 2 days was not effective.
E L Schmidt, M M Ruetze, D W French
Biological control of sapstain fungi in wood
1996 - IRG/WP 96-10158
Sapstain fungi can cause serious damage to wood and wood products, resulting in a significant economic loss for the wood products industry. The purpose of the present investigation was to determine whether the sapstain in wood caused by sapstain fungi could be biologically controlled. Biological control of sapstain fungi in wood was demonstrated in field trials with nonpigmented isolates of Ceratocystis spp. and Ophiostoma spp. These isolates lacked melanin-like pigment when grown on agar plates or wood chips. Inoculation of yellow pine log sections with the isolates prevented wood from biodiscoloration. The results indicate that the nonpigmented isolates can be used for the biological control of sapstain in wood.
S C Croan
Laboratory evaluation of chlorothalonil formulation for stain and mold control on rubberwood and maple
1998 - IRG/WP 98-30175
We evaluated the efficacy of several chlorothalonil and carbendazim fungicides (F1 and F2), etc. in the control of mold and stain fungi on rubberwood and maple. The results showed that these formulations effectively inhibited the selected fungal species such as Aspergillus niger, Penicillium sp., Trichoderma sp. (P71H), Aureobasidium pullulans, Ceratocystis minor (C-188), Ceratocystis pilifera (RWD 9472) in laboratory tests.
Mingliang Jiang, T L Highley, L Ferge, T L Woods
Controlling the sapstain fungus Ceratocystis coerulescens by metabolites obtained from Bjerkandera adusta and Talaromyces flavus
1993 - IRG/WP 93-10024
Sapstain causes severe damage to wood and wood products, posing a major economic problem for the wood industry. The purpose of this study was to determine if metabolites from Bjerkandera adusta and Talaromyces flavus would (1) decolorize stain in wood caused by Ceratocystis coerulescens and (2) prevent sapstain by Ceratocystis coerulescens. We studied the interaction of the sapstain fungus Ceratocystis coerulescens against the test fungi Bjerkandera adusta and Talaromyces flavus in dual cultures on agar medium. The metabolites obtained from test fungi were examined on pine veener disks stained by Ceratocystis coerulescens. Our results indicate that the test fungi were antagonistic to the sapstain fungus Ceratocystis coerulescens. The combination of metabolites from the antagonists decolorize the sapstained pine veener disks and killed the existing growth of Ceratocystis coerulescens.
S C Croan, T L Highley
Destaining wood sapstains caused by Ceratocystis coerulescens
1996 - IRG/WP 96-10159
Fungal sapstain does not reduce the strength of wood, but it does discolor the wood, detracting from its appearance and decreasing the value of wood and wood products. The purpose of this investigation was to assess whether wood sapstain caused by Ceratocystis coerulescens could be destained and existing growth eradicated. The hydroxyl radicals generation under optimized conditions destained the sapstain on southern yellow pine veener disks caused by Ceratocystis coerulescens and killed the existing growth of sapstain fungi. Results indicate that the sapstain, melaninlike pigments of hyphae in pine disks, was destained and the existing growth of Ceratocystis coerulescens (Munch) Bakeshi [C-262] eliminated. As a result, sapstained wood and wood products with sapstain fungi can be salvaged, thus expanding our supply of usable wood.
S C Croan
Application of a novel strength evaluation technique during screening of wood preservatives
1986 - IRG/WP 2262
The effectiveness of CCA and ACA in treated aspen mini stakes tested using a novel bag procedure, with unsterile soil fortified with Chaetomium globosum and Ceratocystis albida, is reported. Good agreement between toxic limits determined using the standard weight loss procedure, and those determined by the strength technique were found, with some indication that the strength loss method is more sensitive. The investigation also showed that the toxic limits for CCA (4.0-8.0 kg/m³) were twice those of ACA (2.0-4.0 kg/m³). In addition, based upon the strength loss, a CCA retention greater than 8.1 kg/m³ was required to prevent decay by Ceratocystis albida in this laboratory screening method.
J N R Ruddick
Development of a disinfection treatment for oak logs to be imported from the USA
1984 - IRG/WP 3283
The European veneer industry depends greatly on oak supplies from the USA. To prevent the accidental introduction of the American Oak Wilt Disease (Ceratocystis fagacearum) into the member states of the EC, a disinfection treatment was developed for oak logs under consideration of the technical requirements of veneer production. Laboratory experiments and field trials in Germany and in the USA showed that the pathogenic fungus can be eradicated from commercial size oak logs with attached bark by fumigation with 240 g methyl bromide per m³ applied for 3 days at a temperature of 3°C or above. For post-treatment monitoring of the fumigation a viability test using tetrazolium chloride was found to be suitable.
W Liese, M M Ruetze
Effect of thickened boron in preventing conidial germination of sapwood-inhabiting fungi
1994 - IRG/WP 94-30059
We evaluated the efficacy of thickened boron preservative "Diffusolä" in preventing conidia germination of sapwood-inhabiting fungi using plate bioassay, Southern Yellow Pine and sweetgum block tests, and green pine log sections. The test fungi were sapstain fungi Ceratocystis coerulescens, Ceratocystis minor, and Aureobasidum pullulans and mold fungi, Aspergillus niger, Penicillium spp, and Trichoderma spp. Conidial germination were inhibited in plate bioassay by Diffusol. Treatment of Southern Pine and sweetgum blocks and green pine log sections with a 10 percent boric acid equivalent of Diffusol inhibited conidial germination of sapstain and mold fungi. In the field exposure, the same Diffusol treatment of green pine log sections inhibited natural basidiospore and conidial germination of forest-inhabiting fungi, thus preventing wood discoloration and deterioration
S C Croan
Characteristics of the pigments produced by sap-staining fungi
1997 - IRG/WP 97-10223
The present study was conducted to characterize the pigments produced by sap-staining fungi, Aureobasidium pullulans (de Bary) Arnaud and Ceratocystis piceae (Münch) H. and P. Sydow. The pigments isolated from tested fungi were identified as melanins by spectroscopic methods (UV and infrared spectra). The UV and the infrared spectra of the fungal pigments were similar to those of the synthetic melanin. The spectra also indicated the similar structures of both fungal melanins. The adsorption bands at aliphatic CH in infrared spectra were stronger in fungal melanins than in synthetic melanin. From elemental analyses, H/C ratio of fungal melanins were higher than that of synthetic melanin. These results suggested that both fungal melanins had a high amount of aliphatic structures.
M Mori, M Takahashi
The relationship between blue-stain and bark beetles
1971 - IRG/WP 19
The attack of bark beetles on standing or in newly-felled stems provides special growth conditions to wood-inhabiting fungi. In the wood attacked by bark beetles, a specific and rich fungus flora is found, and from these fungi the economically important group of blueing fungi has been more thoroughly investigated. These fungi live on nutritive substances present in the cells, especially in the medullary rays and other parenchymatous cells. They attack lignified cell walls only to a limited extent but in the ray cells they may cause considerable destruction. Some of these fungi may attack the secondary cell walls where they develop cavities. The blueing fungi attack standing trees when their moisture content is low as well as timber at different stages of storage before it is completely seasoned. They spread very quickly both radially and longitudinally and thus they may cause rapid discolouration and considerable financial losses. The greatest losses are caused by blueing fungi which attack newly felled timber in the forest simultaneously with the infestation of bark beetles. Von Schrenk (1903) has already pointed out the relationship between the attack of the bark beetles and the blueing of the wood which at this time was thought to be caused by one fungus Ceratocystis pilifera. Later.the number of known Ceratocystis species which are, over the whole world, the most common fungi associated with the attack of bark beetles, have amounted to 80-90 at the present time, and they have been studied most thoroughly by R W Davidson (numerous papers between 1935 and 1970) in the USA. The greatest number of species has been found in North America, where the variability in host trees and in climatic conditions is greater than in North Europe.
The influence of causing primary blue-stain fungus Ceratocystis imperfecta on selected properties of Scots pine wood
2002 - IRG/WP 02-10425
The effects of development in wood the fungi causing blue-stain on the wood properties are not univocal. There were been undertaken investigation to clear the influence of such fungi on selected physical and mechanical properties of Scots pine wood. Wet sap wood samples of fresh cut Scots pine wood (Pinus sylvestris L.) were infested with pure culture of Ceratocystis imperfecta Mill. et Grenz and exposed into its action through 1, 3 and 12 month. The properties of the infested wood and their twin control samples were determined after each incubation period. The wood became the grey-black colour. The complete change of colour - ?E – measured by colorimetric Datacolor equipment was about 30 already after 1 month. The blue stain depth was from 1,0 mm - after 1 month to 5,0 mm (=whole cross - section) after 12 months. The absorptiveness of the stained wood greatly increased after 3 and 12 month of being infected by fungus. There was a tendency to drop the compression along the grains of blue stained wood in all investigated periods, but statistically essential changes appeared after only 12 months of the fungus action (mean drop 5%). The decrease of the impact of blue stained wood was statistically essential after 3 and 12 months of the fungus action (mean drop 13%). The statistically essential decrease in strength of wood was stated also by measuring of logarithmic decrement of torsional vibrations (mean drop 6%) and modulus of torsional rigidity (mean drop 2,5%). The stated changes in blue stained wood may to influence negative on usefulness of wood.
Database of sapstain fungi affecting lumber, logs and trees
2004 - IRG/WP 04-10534
Sapstain fungi discolour lumber, logs and tree sapwood and are often mistaken for moulds, which cause a superficial discoloration. Stained wood has a lower market value. Further, because stained wood products can potentially carry pathogenic fungi, such products may be refused by importing countries. Addressing these issues involves developing ways for accurately identifying staining fungi, documenting how they are geographically distributed, and developing ways of monitoring fungal transfer in wood products. To respond to these needs we are constructing an “Ophiostomatoid fungi” database that will be accessible via Internet. The objective is to provide university, industry, and government agency with a resource that offers key information pertinent to trade and environmental issues. The database includes information on the genera Ceratocystis, Ceratocystiopsis, Leptographium, and Ophiostoma. To support identifying isolates, it has a flexible taxonomy / morphology search tool that gives access to detailed descriptions of fungal characteristics, micrographs and diagrams. Each fungal species is described by morphological and molecular characteristics, physiology, habitat, and geographic distribution. To support molecular identification, sequence data are directly linked to NCBI/Genbank data pages. To support work on fungi in forests, wood and wood products, links connect to websites of insects which can vector fungi, of trees, and of mycology. We seek national and international partners who will actively contribute to improving and expanding this resource.
S Lee, F de Giuli Vallverdu, S Alamouti, Jae-Jin Kim, A Uzunovic, C Breuil
Enzymatic study of Ceratocystis sp., blue-stain fungi on Pinus nigra
1999 - IRG/WP 99-10315
One of the main problems that the forest exploitation industry has with Pinus nigra wood is the blue-stain fungi, whose causing agent is unknown. Therefore, the objective of this work has been to study, through enzymatic tests of the isolated cultures, if these fungi infect Pinus nigra in any specific way. After the incubations, isolates of Ceratocystis were obtained. These were cultured in a saline medium with sawdust of Pinus nigra and Pinus sylvestris, which were used as reference species. At different incubation times, carboxymethylcellulase, xylanase, cellobiohydrolase, laccase and manganese peroxidase were determinated. The results obtained show that the cellulolytic enzymes and laccase have higher activity on Pinus nigra sawdust than on Scots pine, while the Mn peroxidase showed higher values on the sawdust of the latter. Likewise, the cultures were developed in the same saline base medium with different monosacarides (glucose, galactose, mannose, xylose and arabinose), and in determining the residual sugar content, a marked prefrence for the consumption of pentoses in respect to the glucose was observed. The enzymatic activity tests carried out by APY ZYM also showed qualitative and semiquantitative differences between the isolated fungi and other Ceratocystis species tested, so, in addition to the above results, this could indicate a certain specificity of these fungi for this wood species.
M T De Troya, F Rubio, D Muñoz-Mingarro, F Llinares, C Rodríguez-Borrajo, M Yuste, M J Pozuelo, J I Fernández-Golfín
Growth inhibitory effects on blue-stain fungi of applied electricity fields
1996 - IRG/WP 96-10167
Exploratory laboratory experiments on the effects of electricity on two blue stain fungi Aureobasidium pullulans and Ceratocystis piceae on wood revealed that a potential gradient of 1 V/cm corresponding to a current of 15 mA (DC), applied without interruption during a 2 week experimental period, leads to an inhibition of the growth of these fungi. Germination is somewhat more sensitive than mycelial growth. Experiments also revealed that a potential gradient of 10-25 V/cm applied for 30 sec, 3 times every 24 h also inhibited the growth of Aureobasidium pullulans. The mechanism by which electricity exerts its growth inhibiting effect on blue stain fungi on wood is presently unclear.
Development of bluestain in commercially harvested logs in Britain
1996 - IRG/WP 96-10150
In Britain, mechanised harvesting of conifer forestry crops is now the preferred method of felling where terrain and access allows. However, use of mechanised harvesters can lead to excessive debarking, loosening of the bark and wood splintering with, on average, about a third of the bark removed from the more severely damaged logs. More bark has also been observed to be lost from logs harvested early in the summer (June) than later in the season (August). In an experiment which ran from June October in 1993, mechanically harvested logs with only relatively small amounts of bark damage (mean 12%) were found to be much more susceptible to attack by bluestain fungi than those processed manually, and the damaged areas were associated with extensive bluestain development around the log circumference. The most dramatic staining was produced by Ceratocystis coerulescens and Leptographium wingfieldii. Bark beetles which act as vectors of some bluestain fungi were excluded from the experimental logs, but other insect genera were found to act as casual vectors of the staining fungi. Harvester design and improved skills of harvester operators cannot significantly reduce the potential amount of blue stain degrade as significant reduction of stain only comes with the very low amounts of bark damage (0-10% of circumference) and this is practically unachievable with mechanised methods. Thus rapid delivery of logs for further processing remains the safest way of minimising the opportunity for fungal attack.
A Uzunovic, J F Webber, D J Dickinson
Biological control of sapwood-inhabiting fungi by living bacterial cells of Streptomyces rimosus as a bioprotectant
1992 - IRG/WP 92-1564
The objective of this study is to evaluate the efficacy of antifungal activity of living bacterial cells for the protection of wood against sapwood-inhabiting fungi. The following sapwood-inhabiting fungi were selected: sapstain --Ceratocystis coerulescens, Ceratocystis minor, Ceratocystis pilifera, and Aureobasidum pullulans; mold fungi --Aspergillus niger, Penicillium spp, and Trichoderma spp. Living bacteria cells as a bioprotectant were studied in the laboratory using Southern pine and sweetgum block tests, and in field exposure trials with green pine log sections. Living bacterial cells inhibited spore germination, and therefore discoloration in laboratory wood block tests and in pine log sections exposed in field tests.
S C Croan, T L Highley
The study of blue stain found in coniferous timber in SR Slovenia (Yugoslavia)
1983 - IRG/WP 1177
The report concerns the problems connected with blue stain in coniferous timbers stored in warehouses at wood-processing plants in SR Slovenia (Yugoslavia). The amounts of spruce-wood (Picea abies Karst.) found to have been infected with blue stain have been measured and some of the fungi causing the stain have been identified and their biology studied. It was found that the percentage of spruce-wood infected ranged between 3.58% and 9.17%, and that the most frequent fungus causing blue stain was Ceratocystis coerulescens (Münch) Bakshi. This is a fungus that grows very quickly (127.9 mm/10 days); the optimal temperature for its growth is about 22°C, and optimal moisture content from 45-55%. Its growth and sporulation are also influenced by different colours of the light spectrum.