Turfgrass Herbicide Alert




LandcareNetwork.org June 17, 2011


Possible DuPont™ Imprelis™ Herbicide Injury to Evergreens


PLANET members in several states have reported injury to some spruce and pine trees following application of DuPont™ Imprelis™ (aminocyclopyrachlor) turfgrass herbicide. Damaged trees have symptoms, such as curling and twisting of new growth, consistent with growth regulator type herbicides.DuPont is in the process of investigating the issue and their initial conclusions indicate that in most cases, where an injury was reported, Imprelis™ was applied in combination with other pre- or post-emergent herbicides or liquid fertilizer. It has been said that most Imprelis™ applications have not resulted in damage to spruce or pine, but obviously cases of damage cause alarm when dealing with a newly released herbicide.

As a precaution and until it can more fully understand the circumstance, DuPont advises to not apply Imprelis™ “where Norway Spruce or White Pine are present on, or in close proximity to, the property to be treated.” Furthermore, DuPont advises, “when applying Imprelis™, be careful that no spray treatment, drift, or runoff occurs that could make contact with trees, shrubs, and other desirable plants, and stay well away from exposed roots and the root zone of trees and shrubs. Consult a certified arborist if you are uncertain about the root zone of specific tree species.” The reported cases indicate that this may not be a simple herbicide drift issue but rather be from root uptake. If that is the case, it would be critical to keep applications away from the root zones of non-target trees and ornamentals.

In a letter to some applicators, DuPont states: “In many geographies, environmental conditions over the past few years have stressed trees, particularly spruces. We have observed unfavorable symptoms in trees on properties that have not been treated with an herbicide. Good growing conditions and appropriate care to minimize stress will enable many trees experiencing signs of stress to recover and return to good health.”

As always, with any pesticide application, make sure to read and follow label directions.

Tom Delaney
Director of Government Affairs
Professional Landcare Network (PLANET)
(800) 395-2522


Professional Landcare Network (PLANET)
950 Herndon Parkway, Suite 450
Herndon, VA 20170
(800) 395-2522 . Fax (703) 736-9668 . LandcareNetwork.org
 The association of members who create and maintain the QUALITY OF LIFE in communities across America.


Arbor Doctor note:  Damage appears to extend beyond evergreens as we are seeing widespread death of honeylocusts.