WEST LAFAYETTE, Ind. (AP) - Plant experts are warning Indiana homeowners to watch for signs of a disease called fire blight that can kill pear trees and has spread more after this year’s harsh winter.
The disease gets its name from the dark brown or black coloring it gives the tree leaves, making them looked scorched, according to Purdue University’s College of Agriculture.
“You can see the blighting on the outside of the branch. It turns black, and it’s very obvious something is wrong,” Tom Creswell, director of Purdue’s Plant and Pest Diagnostic Laboratory, told the Journal & Courier (http://on.jconline.com/U2hWeJ ).
Other signs of the disease include wilting shoots and black cankers on branches.
Creswell said Indiana typically has some instances of fire blight each spring, but that the harsh winter increased occurrences of the disease, which is passed from tree to tree by water in open cuts or cracks in the bark. It’s most prevalent in the spring because of warmer weather, coupled with rain.
It can be spread by wind, rain, insects and bees, Creswell said.
Purdue University Extension provides further details on the diseases causes, symptoms and treatment in a brochure titled “Fruit Diseases: Fire Blight on Fruit Trees in the Home Orchard.” The brochure can be downloaded from the Purdue Extension website for no charge.
Creswell suggests pruning the affected parts of the tree 12 to 18 inches beyond the diseased part and into green, healthy-looking tissue. That’s because blight might be deeper than is visible.
Pruning should take place in the hot and dry part of summer or during the winter, as the disease tends to stop spreading during those times, Creswell.
“If they can prune it out in the wintertime before the spring growth starts, that’s the best time,” he said.
Information from: Journal and Courier, http://www.jconline.com