Disease Alert: Fire Blight In Bradford Pears
April 3, 2017
When performing our regular inspections on your property, we keep an eye out for signs which might indicate trouble with your trees, including weak and overburdened branches, unhealthy growths, and warning signs of common disease problems.
Scorched leaves are a signal to watch for
One such disease with observable symptoms in spring is Fire Blight, which is named for the scorched appearance of badly infected leaves. Caused by a bacterium (Erwinia amylovora), this deadly disease affects a number of tree species, including pear, quince, and apple trees. It is also known to attack firethorn (Pyracantha species). If left untreated, this destructive disease can take out large branches as well as entire trees.
How did your plants contract fire blight?
Many of the plants affected are grown for their spring flowers, which is unfortunately the most common entry point for infection. Damaged twigs and leaves are also ways for bacteria to find their way into your trees. Visiting insects, rain and wind spread the infection during the warm, moist weather of spring, typically affecting new growth just as it emerges. Since the tender new growth is the most vulnerable, avoid using high nitrogen fertilizers in the early spring since it stimulates new growth, particularly if fire blight has been a problem in the past.
What does fire blight look like?
Leaves and stems turn brown or black at a rapid rate and branch tips develop oozing lesions. As the disease moves into the tree, areas of branches will begin to turn black. Insects are attracted to these watery places and they help spread the bacterium. These brownish spots are difficult to see, so they often go unnoticed until the leaves begin to shrivel. As with most diseases, early detection is key for treatments to work swiftly and effectively.
Skilled Treatment: Spray & Prune
A fungicide spray, applied while the flower blossoms are open can prevent new infections, but will not help with infected wood. Control is most effective when treatments are begun early in the spring season. If your tree or shrub has fire blight, every attempt should be made to reduce the spread of the bacterium inside the tree tissue. Often, we will recommend a specialized treatment injected directly into the trunk of the tree to suppress the spread of the disease within the tree. These injections are typically most effective when administered at bud break in spring.
Removing infected branches is a key part of treatment. Prune the affected branches about a foot below the diseased areas to stop the infection. If the bacteria finds its way into the trunk of the tree, it’s possible that the tree might have to be removed. By combining both tree injections and branch removal, you’ll give your tree the best chance for recover.
Another reason for skilled tree care
Healthy, more established trees are generally less susceptible to many diseases, including fire blight. Younger trees, and trees already under stress, are significantly more susceptible to diseases and pests. Maintaining all of your trees with proper watering and feeding, plus skilled pruning, will ensure stronger, more vigorous trees.