Red Oak Logs Research Articles

Lumber Volume and Value Recovery from Small-Diameter Black Cherry, Sugar Maple, and Red Oak Logs

While only a very small percentage of hardwood logs sawn by conventional sawmills in the U.S. have small-end diameters less than 10 in, portable and scragg mills often saw smaller logs. With the closure of regionally important oriented strand board and pulpwood operations, small-diameter logs are considered to have no value in some markets. This study was conducted to assess the volume and value of lumber produced from small-diameter hardwood logs of three important commercial species: red oak, sugar maple, and black cherry. Value assessments included determining yields for both green and kiln-dried lumber subjected to different dry kiln schedules. Volume and grade recovery from these small-diameter logs were lower than prior studies suggested. The value of recovered lumber per ft3 of log volume was not found to be affected by log small-end diameter class for black cherry and red oak, but the value was significantly affected for sugar maple. The loss in lumber value that was attributed to kiln-dried based grade changes was greatest for red oak and least for sugar maple. For red oak, the modified dry kiln schedule did not affect the lumber value. For black cherry and sugar maple, there were kiln-schedule based differences in the value of the dry lumber recovered.

Variation Among Phytophthora cinnamomi Isolates from Oak Forest Soils in the Eastern United States.

Phytophthora cinnamomi isolates from geographically diverse oak forest soils in the Mid-Atlantic regions were studied to determine the extent of genotypic, phenotypic, and pathogenic variation. Four microsatellite loci were targeted for genetic analysis. Phenotypic characteristics measured included sexual and asexual spore dimensions and colony growth rate and morphology. Red oak (Quercus rubra) logs were inoculated with selected isolates to determine relative pathogenicity. Microsatellite analysis showed that the genetic variability of P. cinnamomi isolates was low, with two predominant microsatellite fingerprint groups (MFG). Isolates in MFG1 (48% of the total isolates examined) were characterized by DNA fragment lengths of 120 and 122 bp at locus d39, 169 and 170 bp at locus e16, and 254 and 255 bp at locus g13. MFG2 isolates were characterized by marker sizes of 122 and 124 bp at locus d39, 161 and 163 bp at locus e16, and 247 and 248 bp at locus g13. Asexual and sexual spore dimensions varied greatly among isolates but were similar to previously published descriptions. Phenotypic differences were most pronounced when data were grouped by MFG; the most significant were colony morphology and growth rate. Neither characteristic was a reliable predictor of isolate genotype. Differences in growth rates of MFGs were observed, with MFG1 being less tolerant at higher incubation temperatures. No variation in pathogenicity was observed on red oak logs. The low level of phenotypic and genotypic variation of P. cinnamomi suggest that other factors such as climate might play a more important role in its northern distribution and the diseases it causes.

Appalachian Hardwood Product Exports: An Analysis of the Current Chinese Market

A mail survey of Appalachian hardwood product exporters was conducted in the fall of 2008 to analyze the export practices for Appalachian hardwood products, specifically the volume of hardwood products exported to the Chinese market, their preferred species, and potential and existing trade barriers between US producers and Chinese customers. Results of the survey showed that the most frequent export destinations of Appalachian hardwood products were Europe, China, Canada, Mexico, and Japan. In 2007, approximately 11.4 million board feet (MMBF, Doyle scale) of hardwood logs and 145.3 MMBF of hardwood lumber were exported to China by the respondents. Approximately 37 percent of the respondents who exported hardwood products to China exported red oak logs, followed by white oak, black walnut, black cherry, and hard (sugar) maple. The top species of hardwood lumber exported to China were red oak, white oak, yellow poplar, black walnut, hickory, cherry, hard maple, and soft maple. Respondents indicated that transportation freight costs and payments are the limiting factors when considering expanding business overseas. The continued decreasing hardwood price has put more pressure on hardwood products exporters to maintain profit margins. Because of the current economic downturn, hardwood production in the Appalachian hardwood region has declined by more than 40 percent. Exports of hardwood products to China will be affected to some extent. However, it is expected that China will remain an important overseas market in the near future.

Measuring the Effect of Internal Log Defect Scanning on the Value of Lumber Produced

In this article, we report on the effect of internal log defect scanning on the gain in lumber value recovery for five hardwood species, consisting of black cherry, hard maple, yellow poplar, red oak, and white oak logs. A total of 29 logs, 6 logs per species and 2 logs each for log Grades 1, 2, and 3, were scanned with a medical X-ray computed tomography scanner to acquire their cross-sectional images. The one exception being for red oak logs, for which we scanned two Grade 1 logs, one Grade 2 log, and two Grade 3 logs. These logs were then sawn in the sawmill to determine the actual value recovered from each log. Virtual logs constructed with the scanning images of these logs were then sawn on the computer using the TOPSAW software. Based on simple live sawing simulations, overall the average value gain for all species and grades was 46%, while the gains for black cherry, hard maple, yellow poplar, red oak, and white oak were 42, 33, 83, 24, and 60 percent, respectively. The average gains for Grades 1, 2, and 3 logs were 27, 47, and 97 percent, respectively. Regression analysis of the gains indicated that while there are no significant differences among the species, the gain for Grade 3 logs was significantly different from other log grades.

Sulfuryl fluoride fumigation of red oak logs eradicates the oak wilt fungus

This work was supported by a grant from the DowElanco Corp. as well as University of Minnesota Agr. Exp. Sta. project 4369. Essential help by James Bean in the fumigation trials as well as statistical evaluations by Peter Scherer (DowElanco) are gratefully acknowledged. Help from consulting foresters Steve Cook and Steve Nelson for tree procurement as well as Kory Cease, Paul Castillo and Tamara Pickens (USDA Forest Service) for technical assistance is also appreciated. Preliminary field trials using red oak logs from trees dying from oak wilt disease were successful in eliminating the oak wilt fungus from sapwood after fumigation with sulfuryl fluoride for 72 h under tarp. These results support earlier laboratory data on the fungitoxicity of sulfuryl fluoride as a potential replacement for methyl bromide treatment of exported red oak veneer logs. However, not all other microorganisms were completely eradicated from oak sapwood at the treatment levels used in this trial.

Fungitoxicity of Sulfuryl Fluoride toCeratocystis fagacearum-In Vitro and in Wilted Red Oak Log Sections

The European Union requires imported red oak logs to be fumigated with methyl bromide to eradicate the oak wilt fungus, Ceratocystis fagacearum. The restriction of methyl bromide would threaten the export of oak, as other fumigants have not been evaluated. Sulfuryl fluoride penetrates wood and has been used extensively for insect control, but fungicidal effects are unknown. The effect of sulfuryl fluoride exposure on 10-day-old C. fagacearum cultures was tested in a closed circuit fumigation chamber at concentrations of 16, 40, 60, 80, 100, and 120 g/m 3 for 24 and 48 h. Rates of 80 g/m 3 for 48 h and 120 g/m 3 for 24 h rendered cultures unable to grow. When stained with Janus Green B, both mycelia and conidia were nonviable. End-sealed log sections from wilted red oak trees were fumigated at 160, 220, and 280 g/m 3 for 72 h. Eradication of C. fagacearum from red oak log sections was achieved after exposure to 280 g/m 3 for 72 h. (concentration x time product = 18,530 g h/m 3 ). Graphium, Verticillium, and Paecilomyces spp. (also isolated initially) were eradicated after the 18,530 g h/m 3 treatment. This is the first report of fungitoxicity of sulfuryl fluoride.