New Method to Treat Ash Firewood
The emerald ash borer has destroyed tens of millions of ash trees in the U.S. since the beetle’s discovery in 2002 in Detroit.
Current treatment standards require ash firewood to be heated to a core temperature of 60 degrees Celsius for a minimum of 60 minutes. To explore an alternative heat treatment option, researchers at Virgina Tech investigated the effectiveness of using a vacuum and steam treatment to kill the insect in ash firewood. Having an effective treatment would allow people to transport ash firewood outside of existing quarantine zones.
Dr. Zhangjing Chen, professor in the Department of Sustainable Biomaterials at Virginia Tech, demonstrated the effectiveness of a vacuum/steam treatment for ash firewood infested with emerald ash borer. The demonstration grew out of earlier studies that showed a vacuum/steam treatment as an effective means to kill insects, molds, fungi, and nematodes in green and dry hardwood pallets and green pallet parts (stringers).
The studies indicate that vacuum/steam treatment cycles take less than half the time of current hot air treatment methods and reduce energy consumption by 25% less.
Image credit: U.S. Forest Service