On Tuesday August 20th, Jeff Slahor of the Appalachian Hardwood Center, assisted Dr Chen of Virginia Tech demonstrate a unique method of phytosanitation of ash firewood, funded by the USDA WERC. The wood sealed in a flexible container, was subjected to vacuum followed by approximately 2 hours of steam. The internal target temperature, as indicated by several thermocouples, of 60 degrees C was reached and held for another hour. The goal was to demonstrate a 100% kill rate of the emerald ash borer.
On Wednesday 21st the container was opened for inspection at the Cacapon State Park, the origin of the wood. The state park has witnessed the rapid loss of its ash trees in just the past two years. Trees had been cut and processed to firewood. A pallet load was treated as described above and the remainder stacked at the park serving as untreated control. A brief presentation to several interested agency representatives from WV, PA, and Virginia as well as three high level representatives of USDA Animal and Plant Health Inspection Service (APHIS) described the method and detailed how it will save time and energy compared to existing treatments.
Following the presentation, the flexible treatment bag was opened and the treated firewood was compared to the untreated firewood. All EAB from the treated wood were found to be dead while the untreated control confirmed that wood had been infested with live EAB -- a clear success.
Picture Captions: (left to right) 1. wood in the bag being treated; 2. treated wood removed from bag; 3. "treated" EAB
Some other items to keep in mind about firewood phytosanitation:
1. Vacuum/steam treatment has commercial application opportunities for sanitizing a variety of wood products, including firewood, pallets and wood packaging materials, and high-value/veneer logs.
2. APHIS plans to include the vacuum/steam treatment process in their treatment manual, specifically for firewood.
3. Thousand canker in walnuts was discussed, specifically pertaining to the Pennsylvania situation. APHIS staff may have an opportunity to use a vacuum/steam treatment facility for cotton in California to test treat high-value/veneer logs loaded on a trailer/container during the upcoming winter season.
4. Various sized chambers may need to be developed to bring this treatment process to commercialization. For example, a stationary chamber for pallets and packaging materials, perhaps a portable unit for treating firewood generated during eradication activities in cities and communities.
5. One other wood product that may fit using the vacuum/steam process (that was not discussed yesterday) could be wood fuel chips destined for the European market.