Submitted to: International Conference on Methyl Bromide Alternatives and Emissions Reductions
Publication Type: Abstract only
Publication Acceptance Date: 9/16/2006
Publication Date: 11/6/2006
Citation: Mitcham, E.J., Monzon, M., Johnson, J.A., Wang, S., Tang, J. 2006. Insect control and walnut quality following large-scale industrial radio frequency treatments. International Conference on Methyl Bromide Alternatives and Emissions Reductions, November 6-9, 2006, Orlando, Florida. pp. 78. 1-4. Interpretive Summary:
Technical Abstract: Industrial-scale radio frequency (RF) treatments producing a minimum temperature of 52°C for 5 min were developed to control insect pests in in-shell walnuts. RF treatments for both unwashed and air dried walnuts resulted in 100% mortality of fifth-instar navel orangeworm larvae, the most heat tolerant target pest. The treatment was effective over a relatively wide range of walnut moisture contents (3-7.5%). Walnut quality was not affected by the RF treatments; kernel color, peroxide values and fatty acid values of treated walnuts were similar to untreated controls even after 20 days at 35°C, simulating 2 years of storage under commercial conditions at 4°C. The RF process significantly reduced the moisture content of the walnuts, especially the shells. The RF treatment developed in this study should also control codling moth, Indianmeal moth and red flour beetle in in-shell walnuts. This technically feasible process would provide a novel, effective, and environmentally friendly phytosanitary treatment technology for the walnut industry.