The disease also attacks apple trees, quince, spiraea, hawthorne and as many as 70 other species. The fact that an ornamental pear, such as Bradford, has been infected is a sign that this could be an unusually bad year for blight, according to Dr. George Philley, Extension plant pathologist. Though it makes the tree unsightly, the disease will rarely kill an ornamental or other pear variety. Ornamental pear tree owners can expect their trees to bounce back later in the year. In the spring, the disease usually first shows up as blossom blight.
Infected blossoms become water-soaked and then turn dark brown.
The disease then moves down the fruit stem, causing the area it infects to become water soaked and turn dark green. From the fruit stem, the disease migrates into the leaves of the blighted spur. Twigs become dark green and oily looking when infected. In contrast, the disease turns apple tree leaves and stems dark brown. Cultural methods involve pruning the infected portion of the stem, four to six inches below the visible symptoms.