February 2018 - By Mark White.

The Virginia Tech, Department of Sustainable Biomaterials is the lead institution in a $500,000, two year grant “Evaluation of vacuum and steam heat as a methyl bromide alternative for the phytosanitary treatment of hardwood and softwood logs.” The funding is provided by the USDA, National Institute of Food and Agriculture and the USDA Forest Service, State and Private Forestry. The lead scientists are Drs. Zhangjing Chen and Marshall White. Also participating are Drs. Henry Quesada and Brian Bond.  Cooperating Institutions include University of Minnesota and Purdue University. 

To prevent the migration of invasive forest pests, logs moving international must be treated. The most common treatment is fumigation with methyl bromide. Methyl bromide is very dangerous to use and a class 1 ozone depleting chemical. With the exception of pre-shipment and quarantine critical applications, the use of this fumigant has ceased by international agreement in the 1992 amendment to the Montreal Protocol. Currently, the second largest use of methyl bromide in the US is for the pre-shipment and quarantine treatment of logs. Earlier research by Drs. Chen and White, has demonstrated that the physics of steam and vacuum can be adapted to the thermal sanitation of logs and thus preventing the international migration of invasive pathogens and insects. Log quality is unaffected and treatments are very efficient. These studies have included successfully treating logs naturally infected with Asian long horned beetles, walnut twig beetles emerald ash borers, and thousand canker and oak wilt fungus. Chen and White have designed and built a portable pilot plant that will be moved around the country during the two years of the current research grant to treat other naturally infested logs for the purpose of developing effective treatment schedules.  These Vacuum/steam treatment schedules will then be included in the USDA treatment manual for commercial application. Dr. Quesada will be conducting a commercial feasibility analysis of the technology and Dr. Bond will be coordinating a national continuing education program to introduce this new technology to stake holders involved in the international shipment of logs.