Terran's Tips

Fire Blight in Bradford Pears

 

Have you ever noticed the leaves on Bradford pears turning a bronze or brown color? This bronzing is followed by dead tissue forming in the tree. This disease is Fire Blight, a bacterial disease which can severely damage apples and pears.

Bradford pears are one of the most common landscape trees found in this area. Unfortunately, they are not without problems. This year with the high humidity and early rainfall, we have experienced more Fire Blight than usual.

Symptoms
Fire Blight symptoms are first observed in the spring. Blossoms appear water-soaked, later turning brown then black. During humid or rainy weather, blighted tissues usually exude a milkylike, sticky liquid or ooze containing the bacteria. At first glance, one might think the tree is suffering from a fertility or water stress problem. As time passes, the twigs and leaves will appear to be scorched.

Control
Fire Blight control is very difficult to obtain. During the late summer when bacterial growth slows, all infected twigs and branches should be pruned out and discarded. The bacteria are usually found somewhat in advance of the obviously diseased tissue. The pruning cut should be made through healthy wood 6-8 inches below the point of visible infection. It is very important that the pruning blade is disinfected after each cut with a 9:1 alcohol to water solution. This will reduce the chances of disease spread. Cankered areas on large branches and trunks should be pruned out during the dormant season.

 

Fire Blight is worse on succulent tissues. Avoid excessive use of nitrogenous fertilizers and excessive pruning, both of which promote succulent growth. Bradford pears have a tendency to promote succulent growth, therefore, remove water sprouts that form on susceptible tree species as they appear. Chemical control is generally not recommended in home landscape situations.

More info on this subject is available at this website.

Please email joanna@woodlandtree.com for any of your tree servicing needs. We are here to help you during these hot summer months and beyond.

Posted by Mark Allen at 14:26