Fire blight on pear trees

Learned on a local radio gardening call-in show that now is a good time to prune out Fire Blight from Pear trees. Fire blight is one of the most destructive bacteria that affects pear and apple trees and is very difficult to control.

The Ohio State University Extension has a great fact sheet here on the symptoms, cause and treatment of Fire blight. I’m sure many university and state agriculture extensions have good information as well.

Fire blight is caused by a bacteria that overwinters around cankers on the trunk and branches. When spring temperatures get above 65F and there is enough moisture, from rain or high humidity, Just one active cankers can produce enough bacteria to infect an entire orchard. The bacterium is spread by splashing rain or insects to open blossoms.

If twigs appear water-soaked, then turn dark brown or black, and bend over, resembling a shepherd's crook or an upside down "J" the tree is probably infected with Fire blight. As the fire blight bacteria move through blighted twigs into main branches, the bark sometimes cracks along the margin of the infected area on the main branch causing a distinct canker and droplets of ooze appear.

Prune 12” below the infected area with disinfected shears. Use a 10% bleach solution to wipe the blade after every cut.

This time of year is still a little early for major pruning of pear trees but you can safely prune to get rid of this stuff.