Imprelis and other herbicide disasters: When good chemicals go bad

Summary

In fall 2010 and spring 2011 landscape and lawn service companies in the Midwest began treating lawns and golf courses with Imprelis, a newly registered broadleaf herbicide for turfgrass.  By early summer 2011 widespread reports of tree death and injury associated with Imprelis applications began to surface.  As continued reports of tree death and damage began to receive national media coverage, the US EPA issued a Stop Sale order for Imprelis in August 2011.  Although the product was actively used for only a few months, DuPont received over 30,000 claims for damages in excess of $500 million.  While the Imprelis debacle is the largest and most widely-known case of herbicide injury to trees, other cases of herbicide damage occur almost daily across the country.  In this presentation, Dr. Bert Cregg, Associate Professor of Horticulture and Forestry at MichiganStateUniversity, will discuss the Imprelis issue and other case studies of herbicide damage to trees.  He will present suggestions for herbicide applicators to reduce the likelihood of tree-herbicide issues and steps that arborists can if they suspect that trees have been damaged from an herbicide application.