AUGUSTA, Maine — State forestry officials have been receiving numerous calls about a disease affecting white pine trees, but they say there should be no rush to cut them down because the trees may yet survive.
Several pathogenic fungi infect the needles of the trees, causing them to turn yellowish brown and fall off, but the problem is not new to Maine or the Northeast. The white pine needle disease epidemic has been occurring in most areas of New England and also New York for at least eight straight years, according to forestry officials. The fungi have been spurred by above-average precipitation in the spring and summer the past decade.
The pathogens infect needles early in spring and develop through the needles during summer and fall. However, the disease is not evident until the following spring, the symptoms usually appearing in early to mid-June, when the infected needles turn color and drop off in three or four weeks.
Needles on infected trees have been changing color and falling off in recent weeks, prompting calls to the Maine Forest Service. Heavy rains have aggravated the problem, leaving the crowns of trees appearing thin.
The disease has inflicted the most damage in western and southern Maine, according to Bill Ostrofsky, a forest pathologist for the agency. However, impacted trees can be found throughout Maine, he said Wednesday. “I can tell you … we can find the needle disease wherever we look for it in Maine.”
Several different fungi are the culprits, said Ostrofsky; the most common is a pathogen known as brown spot.
The Maine Forest Service has received a lot of calls recently from homeowners, indicated Dave Struble, an entomologist for the agency, as well as owners of woodlots.
“Looking at their lots, they see needles dropping like they would normally drop in the fall, and of course it isn’t fall, and the tops are quite thin,” he said Wednesday.
Struble advised homeowners and woodlot owners to “avoid the knee-jerk reaction” of immediately cutting down or thinning affected trees. Trees that recently have dropped some needles “have not died,” explained Struble. “They may in fact recover.”
“There’s no real need to rush out right now,” he added, and remove or thin damaged trees. He recommended that woodlot owners consult foresters and that homeowners contact an arborist for professional advice.
However, thinning may be the best course of action, he added. “If a stand has not suffered much stress, getting it thinned and opened may help improve the health of individual trees,” said Struble.
State foresters are collaborating with other states and the U.S. Forest Service to determine the scope of the problem and identify solutions, the Maine Forest Service said in a bulletin it issued this week. A survey of damaged trees in Maine is underway, and results will be compared with defoliation estimates from previous years.
The severity of the disease appears similar to that of past years, according to the Forest Service, but some trees that have been impacted and weakened for a number of consecutive years are now dying. In addition, other secondary damage is occurring from insects and other diseases.
“It appears that for the foreseeable future, white pine will be another threatened resource unless the needle disease epidemic abates, either from a break in the weather and moisture patterns, or from some other as yet unknown reason,” the agency said in a bulletin issued on Tuesday.
For help finding a resource professional, contact the Maine Forest Service at 800-367-0223.
For more information about the Maine Department of Agriculture, Conservation and Forestry, go to: www.maine.gov/dacf.