Agricultural Research Service scientists in Yakima, Washington, are testing food-grade surfactants as a new method of ridding packed sweet cherries of mites, thrips, and other surface-feeding pests.
According to entomologist Dr. Jim Hansen, such pests pose a marketing problem, rather than a production one, since they can occur on cherries that have been packed for domestic sale or export.
Hansen is experimenting with dips, baths, and sprays containing polydimethyl silicone emulsions and other food-grade surfactants that wash the pests off the surface of the cherries. Surfactants are typically used as wetting or dispersing agents in products ranging from soaps and shampoos to paints and insecticides.
In 2005, the ARS entered into a research agreement with the California Cherry Advisory Board. Under the agreement, Hanson will do research to identify emulsifiers and other surfactants that will remove a variety of pests. Recent studies by Hansen and others have shown that some silicone-based surfactants will remove spider mites, thrips, and mealybugs from apples and pears. He¹s also looking for ways to identify exposure times that won¹t delay on-line packing operations, and will compare the effectiveness of spraying cherries versus immersing them in surfactants.
Hansen¹s collaborators at the University of California-Davis have examined surfactant-treated cherries for fruit damage, but have found nothing significant.