Norway maples with wilting branches in Ann Arbor, Plymouth and Canton
July 10, 2009 - Author: Dave Smitley, Michigan State University Extension Department of Entomology
Editor’s note: This article is from the archives of the MSU Crop Advisory Team Alerts. Check the label of any pesticide referenced to ensure your use is included.
Guerin Wilkinson from Greenstreet Tree Care and Kay Sicheneder, City of Ann Arbor worker, have reported many cases of branch-wilting on Norway Maples and some sugar maples in Ann Arbor, Plymouth and Canton. Here is how they describe the symptoms:
“Everyone at our company (Greenstreet) has noticed an odd thing happening to sugar maples and Norway maples this year. Branches scattered throughout the crowns are dying. Leaves started to come out, then the branches died and discolored with half-sized leaves remain. In the office, I've been getting regular comments from people in the field, plus some phone calls about this. I believe the branches wilted and died soon after pushing out the leaves. We started seeing symptoms early in the season when water stress was not an issue. Yesterday, I reviewed some of the trees that the city of Ann Arbor forestry department told me about. The wilted branches are scattered throughout the crowns. These trees are not in great condition overall, but rather ones more prone to decline due to age and poor site conditions.”
At this point we don’t know the cause of the reported symptoms or how wide-spread it is across the state. Bob Bricault (MSU Extension, Wasthenaw County) and Gerry Adams (MSU Professor of Plant Pathology) will meet Guerin to visit some of these sites next week. Some of things they will be looking for are: Verticillium wilt, leaf scorch (but not expected to be bacterial leaf scorch), anthracnose and borer galleries or emergence holes. We will give you an update on what they find in the next Landscape Alert issue. Gerry Adams found an old MSU bulletin on “Maple Environmental Stresses” that may be helpful.