Penn State scientists are investigating new approaches to eliminating pests and pathogens from wood packaging. Engineers and entomologists in Penn State’s College of Agricultural Sciences are looking at both microwave and radio wave treatments as alternatives to the use of heat treatment and methyl bromide, in research sponsored by the USDA Methyl Bromide Transitions Program.
“Methods of killing pests and pathogens — known as phytosanitation measures — are required for all solid-wood packaging material, such as wooden-constructed shipping pallets, used for import/export commerce worldwide,” said John Janowiak, professor of wood products engineering, in a Penn State release.
“These measures are mandated under the United Nations Food and Agriculture Organization’s International Plant Protection Committee,” he said. “The goal of ISPM-15 is to significantly reduce the risk of introduction of alien invasive insects and pathogens that can kill native urban and forest trees, destroying commercial forests and landscape trees.”
“Our research includes a diverse array of experimental data collection and studies on how dielectic heating interacts with wood,” Janowiak said. “We are evaluating the efficacy of microwave and radio-frequency energy — using both batch and continuous processes — to rapidly sterilize solid-wood packaging materials. These treatments are designed to replace methyl bromide fumigation.”
Kelli Hoover, professor of entomology, said that progress on microwave has progressed to the point that a formal submission on the use of microwave energy under ISPM-15 has been recommended for approval to the Standards Committee of the International Plant Protection Convention.
“Assuming our submission passes country consultation, microwaves will be the first alternative treatment adopted under ISPM-15 since it was implemented almost 10 years ago,” she said. “We currently are tweaking the treatment schedule and guidelines for commercial implementation.
“But because radio frequency — also known as RF — has better penetration depth than microwaves, the team is currently focused on developing the efficacy data set and treatment schedule for submission of RF heating for adoption under ISPM-15.”
While phytosanitary control is the primary objective of the research, the team also is also assessing the overall environmental and economic benefits of the competing technologies. With this in mind, Charles Ray, associate professor of wood products operations, is leading life-cycle analysis of the alternatives.
“Stopping the movement of pests and diseases can be done through a number of means,” he said. “However, each potential solution produces different impacts on climate change and sustainability measures, such as carbon dioxide emissions, aquatic ecotoxicity and use of nonrenewable energy, to name just a few. Our project is designed to ensure that the analysis presented to the international regulatory bodies includes an assessment of these impacts, as well as the relative cost of each.”
According to Penn State, this comprehensive approach to the research has been noted by the international community. At a presentation of preliminary results in Lisbon, Portugal, last September, Hoover received encouragement from several delegates of other countries to continue the life-cycle impact assessment component of the project.