Submitted to: Postharvest Biology and Technology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/25/2005
Publication Date: 6/1/2006
Citation: Hansen, J.D., Heidt, M.L., Neven, L.G., Mielke, E.A., Bai, J., Chen, P.M., Spotts, R.A. 2006. Effect of a high-pressure hot water washing system on fruit quality, insects, and disease in apples and pears. Part III: Use of silicone-based materials and mechanical methods to eliminate surface pests. Postharvest Biology and Technology. 40:221-229
Interpretive Summary: Surface pests on apples and pears reduce their market value and disrupt foreign commerce. Researchers at the USDA - ARS Yakima Agricultural Research Laboratory, Wapato, Washington, examined different methods to reduce surface pests along a simulated packing line. Submerging the fruits in water with a surfactant, followed by brushing and pressurized water sprays, removed a considerable portion of these pests without major modification to packing procedures. These results provide specifications for fruit packers to use for maximum efficacy in removing pests with minimum effect on fruit quality.
Technical Abstract: Surface arthropods on pome fruits can cause export problems and disrupt commercial markets. Eliminating insects and mites on the packing line would be the last opportunity to provide for pest-free products. In this study, we used an experimental packing line to evaluate techniques using different surfactant baths, pressurized water sprays, and styles of rotating brushes to remove field-collected and laboratory-reared grape mealybug, Pseudococcus maritimus (Erhorn) (Homoptera: Pseudococcidae), the diapausing twospotted spider mite, Tetranychus urticae Koch (Acari: Tetranychidae) and the wooly apple aphid, Erisoma lanigerum (Homoptera: Aphididae). The organosilicone Silwet L-77 was no more effective than a silicone-based food grade defoamer in aiding removal. Mechanical methods, such as the style rotating brushes and pressurized sprays, were significantly effective in removing surface arthropods. No improvement in removal occurred when pressure was increased beyond 400kPa. These techniques can be easily adapted to commercial facilities and will reduce the incidence of surface arthropods on marketed fresh fruits.