Fire blight is a systematic, contagious bacterial disease that largely affects fruit trees. The bacteria, which are called, erwinia amylovora, attacks the blossoms in early spring. It then moves up the twigs and branches through the tree’s system. The name ‘fire blight’ comes from the scorched appearance of the infected stems and bark. These areas may appear black, shrunken and cracked. The blossoms will turn brown, wilt and die about 1-2 weeks after infection occurs.
Fire blight may also exhibit an amber-colored ooze, which is heavily covered with bacteria, from the bark of the tree. When spring temperatures begin to climb between 60 degrees to 80 degrees Fahrenheit, optimal conditions are created for spreading the disease. The bacteria are brought out of dormancy. Bees, insects, birds, splashing rain and wind can easily spread the bacteria and the resulting fire blight disease.
Fire blight commonly affects apple and pear trees, both the fruit-bearing and ornamental types. It can also affect quince trees and other members of the Rosaceae family which includes some rose varieties and raspberry plants.
How do you manage fire blight in affected fruit trees?
Well, any excessive amount of new growth on your tree is easily susceptible to fire blight infection. To avoid this susceptibility to fire blight in your trees, you should use a low-nitrogen fertilizer during the growing season. You will preferably stop before the month of July. You should also only fertilize when it’s necessary. A soil test will help you determine whether or not your soil needs a fertilizer application. Fertilizers, as a rule, should only be used to supplement nutrients in soils that are lacking them.
When fall rolls around, you’ll want to do a thorough cleanup around your trees. Collect all pruning debris, mummified fruit and fallen leaves. You’ll want to move them away from your trees and destroy them. These should not be composted. Why? This will prevent the bacteria from overwintering in the debris and spreading.
You should always remove blighted wood from infected trees and shrubs. This will help keep the disease from spreading. You will want to prune off all infected branches to at least 8 inches below the blighted area. Some experts recommend you do this to 12 inches below the blighted areas. If you have questions, please feel free to call us at 512-341-8888. We can take care of the pruning process for you. You will then want to burn and destroy the affected branches.
Be sure to remove tree suckers and water sprouts during any season. This growth is fast-growing and tender so it is vulnerable to infection. There are also chemical treatments for fire blight if you want to investigate them.
Remember that there’s no single practice that will ensure complete control of fire blight. We’ve given you some suggestions here. Hopefully this piece gives you an understanding of fire blight and how to control it if you discover it in your trees.