Does Surround Have Non-target Impacts on New England Orchards?

The University of Vermont Apple Program received a USDA grant to study the long-term effects of “particle film technology” on Northeast apple orchards. This technology has been commercially available to growers since 2001 in the kaolin clay–based product Surround. Surround is viewed as a potential alternative for some organophosphate uses in orchards. It is considered a “Reduced Risk Pesticide” by the EPA, indicating that it has characteristics such as very low toxicity to humans and non-target organisms including fish and birds, and low risk of groundwater contamination or runoff. The material also meets all Federal and State standards for use in organic crop production, and may be an important component in that expanding field. Currently for apples Surround is labeled for control of leafhoppers and overwintering oblique banded leafroller, and suppression of codling moth, plum curculio, apple maggot, green fruitworm, and a number of other insects. When applied to the tree, Surround forms a white physical barrier on the surface of fruit and foliage. This particle film barrier acts as a pest deterrent by either directly repelling insects or making feeding, egglaying, or colonization sites unrecognizable or unsuitable. By its nature, this technology is extremely dependent on thorough coverage of the fruit and foliage. Dilute or near dilute applications are necessary and application rates can range from 25 to 50 pounds per acre on apples. The current material label states that “When applied at recommended rates and frequencies, benefits such as increased plant vigor and improved yields may occur in certain apple cultivars. Under high ambient temperatures, Surround reduces canopy temperature and, therefore, can help to reduce heat and water stress. Many cultivars have shown improved fruit color, smoothness, and size with less sunburn, and cracking when Surround is used.” However, much of the previous research on these variables has been performed in warmer, semi-arid, and sub-humid environments. Application of Surround at full rates has been suggested to reduce canopy temperature due to reflectance of solar energy from the white film. The objectives of our research are to determine potential non-target effects of thorough coverage of kaolin film on apple tree vigor, productivity, and fruit quality, including an economic assessment of the gross monetary value of the crop, and to determine non-target effects of kaolin film on diseases and bird damage (we are referring to these effects as ‘non-target’ because kaolin films have been developed and subsequently labeled primarily to manage insect pests) under the relatively cool and moist climate of the Northeast.