The Department of Agriculture and Consumer Services and the EPA have approved a state label for use of Stinger (clopyralid) on strawberries grown in Virginia. Dr. Henry Wilson, Weed Scientist at the Eastern Shore AREC, and I both supported the effort to obtain this state registration.
Clopyralid is used on other crops, including Christmas trees, certain ornamental trees and shrubs, asparagus, field corn, noncrop areas, and turf. This herbicide has been in the news recently regarding persistence in compost. For a discussion of the compost issue with clopyralid, see my article in the July/August 2003 Virginia Turfgrass Journal. Apparently clopyralid can persist in compost under certain circumstances, and can harm sensitive broadleaf crops like tomatoes or snap beans if such compost is applied to these crops. This should not be an issue, though, with clopyralid use in strawberries.
Stinger is a postemergence herbicide that controls certain broadleaf weeds, especially those in the composite (aster), legume, and nightshade families. Some of the weeds that Stinger will control include white clover, red clover, vetch, common ragweed, horseweed, groundsel, and eclipta, with suppression of mugwort, Canada thistle, dandelion, and buckhorn plantain. Growers must be able to identify their broadleaf weed problems since Stinger will not control other broadleaves, such as spotted spurge or yellow woodsorrel (Oxalis). Stinger will not control grasses or sedges. For optimum results, Stinger should be applied to young, actively growing weeds under sunny skies and good soil moisture. Rainfall soon after application could reduce effectiveness. Injury symptoms are similar to that seen with 2,4-D and related growth-regulator herbicides, such as leaf cupping and twisting of petioles and stems.
Stinger can be applied to strawberries at 1/3 pint per acre in the spring. Do not apply within 30 days of harvest. Up to 2/3 pint per acre can be used after harvest. Growers who intend to use the product in strawberries must sign a waiver of liability.
Originally printed in Virginia Vegetable, Small Fruit and Specialty Crops – November-December 2003.
Virginia Cooperative Extension materials are available for public use, reprint, or citation without further permission, provided the use includes credit to the author and to Virginia Cooperative Extension, Virginia Tech, and Virginia State University.
Issued in furtherance of Cooperative Extension work, Virginia Polytechnic Institute and State University, Virginia State University, and the U.S. Department of Agriculture cooperating. Edwin J. Jones, Director, Virginia Cooperative Extension, Virginia Tech, Blacksburg; M. Ray McKinnie, Administrator, 1890 Extension Program, Virginia State University, Petersburg.
July 28, 2009