PULLMAN, Wash. — Replacing chemical fumigation of apples and cherries grown in Washington with low-pressure treatments is the focus of research being conducted by Shaojin Wang, an assistant research professor of biological systems engineering at Washington State University.
Wang has been investigating the use of radio-frequency technology to control postharvest infestations for more than ten years. Agricultural commodities that must be stored are potential carriers of a wide range of exotic insect pests which may cause major economic losses when accidentally introduced locally. To reduce the risk of introducing pests and to retain the market value of the produce, quarantine or phytosanitary requirements must be met for international trade.
Radio-frequency technology has been found to be an effective phytosanitary technique with dry products such as nuts and legumes, but is less suitable for fresh fruits such as cherries or apples due to their increased heat sensitivity. Wang and his colleagues have been investigating other technologies, leading to research into low-pressure methods for disinfestation.
Low-pressure storage technology changes the normal composition of air, creating an environment inhospitable to pests that would otherwise attack the crop. While controlling pests, fruit is kept fresh without over-ripening or senescing.
Wang is working on a technically effective and environmentally sound process to disinfest cherries and apples using low-pressure methods. He said that preliminary research has determined that low-pressure treatments on certain fruits are acceptable without causing adverse effects on product quality but more studies must be conducted on the low-pressure chambers before the technology can be commercialized. Wang said the goal of the research project is to “provide long-term, sustainable and environmentally-friendly postharvest pest management solutions to the challenges facing export marketing of apples and cherries.”
The project is funded by a USDA-NIFA grant. Wang has two co-investigators, Tom Davenport, a horticulturist at the University of Florida, and Judy Johnson, a USDA-ARS entomologist based in Parlier, Calif. Wang said the project is also supported by Atlas Technologies, a low-pressure equipment company located in Port Townsend, Wash.