Forest
Stewardship News Release
July
23, 2003 - For Immediate Release
Contact: Rance
Harmon, Phone: 814-863-0401 E-mail: rsh144@psu.edu
Heavy
Rainfall Causes Fungal Disease in Pennsylvania Trees
By:By Elizabeth Webster,
Penn State Forest Resources Extension Writer
This year’s heavy rainfall has been as damaging to our trees as it has been dampening to our spirits. Anthracnose, a fungus that affects deciduous trees such as maple, dogwood, ash, and most severely, white oak and sycamore, has stressed trees statewide this year. John Holowid, extension agent for integrated pest management at Penn State says that some sycamores have lost up to ninety percent of their leaves this summer. “I’m afraid people will start cutting the trees down,” he says.
A tree affected with anthracnose has brown and shriveled leaves that may progressively die and drop off. Though unsightly, the fungus does not tend to kill trees. According to Norm Kauffmann, forest pest management specialist for the Pennsylvania Bureau of Forestry, trees in the southern part of the state (near Juniata and Dauphin counties) have already begun to refoliate. Trees in the northern half of the state have not fared as well and may not grow new leaves until next year. Kauffmann advises, “Just because there’s no leaves on it doesn’t mean it’s dead. Some people are too quick to reach for the saw.” To check the health of a tree, examine the tips of the branches for a slight greenish color, or snap off a twig and look for live wood.
Anthracnose symptoms appear in early spring when fungal spores infect leaf and flower buds. If conditions continue to be favorable for the spread of the fungus, as they have been this year, symptoms will persist and possibly worsen in late spring and early summer. Trees infected with anthracnose for consecutive years will weaken and become vulnerable to other pests and diseases. Kauffmann suggests that concerned homeowners and landowners can help by fertilizing their trees in the fall.
This season’s cool, damp weather has had far-reaching effects. Anthracnose has damaged trees in Michigan and Ohio as well as Pennsylvania. Fungal diseases similar to anthracnose have affected cherry and willow trees. Cherry leaf spot also causes leaves to drop prematurely. Willows suffer from scab and black canker, which causes wilting of leaves and shoots.
Not all effects have been negative however. The gypsy moth, responsible for large-scale defoliation and death in Pennsylvania’s forests, is in decline thanks in part to a fungal disease that attacks the caterpillars. In March, the Pennsylvania Department of Conservation and Natural Resources (DCNR) announced that they will not spray insecticide for gypsy moths this year, as they have in previous years.
The Pennsylvania Forest Stewardship Program provides publications on a variety of topics related to woodland management for private landowners. For a list of free publications, call 1-800-235-WISE (toll-free), use our on-line Contact form, or write to: Forest Stewardship Program, Forest Resources Extension, The Pennsylvania State University, 320 Forest Resources Building, University Park, PA 16802. The Pennsylvania Bureau of Forestry and USDA Forest Service, in partnership with the Penn State's Forest Resources Extension, sponsor the Forest Stewardship Program in Pennsylvania.
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