RADIO FREQUENCY HEAT TREATMENTS TO DISINFEST DRIED PULSES OF COWPEA WEEVIL

Dried pulses, such as chickpeas, green peas or lentils, are valuable export commodities in the US Pacific Northwest. A major problem in the marketing of these products is infestation by insect pests, which may cause importing countries to require phytosanitary treatments before shipment. Typically, chemical fumigants are used to disinfest product, but regulatory issues, insect resistance, environmental concerns and the increase of the organic market have caused the industry to explore non-chemical alternatives. One possible alternative is the use of radio frequency (RF) energy to rapidly heat product to insecticidal levels. This paper reports preliminary results from our investigation into the potential of the non-chemical treatment method to control insect pests in dried pulse products. Materials and Methods. Determining most heat tolerant stage: The relative heat tolerance of cowpea weevil stages was determined using a computer-controlled heat block system designed by Washington State University (Ikediala et al. 2000, Wang et al. 2002). Cowpea weevils were treated in mung beans, a small legume that fit within th