Bradford pear infected with fire blight (Photo contributed) Ornamental pears are still a favorite among homeowners and landscapers. They are fast growing, require very little maintenance, and are attractive trees. However, ornamental pears usually have a life expectancy of 10-15 years. After this time frame, pear trees will become very unattractive and will actually "self-destruct." The limbs become brittle, weak, and the trunk may actually start to split. If you have fairly young ornamental trees that have dry, brown leaves scattered about the tree, then your tree may have a disease known as fire blight. Fire blight turns the tips of the branches black as though they were burned by fire.

Identification

As you attempt to identify fire blight, pay close attention to the infected limbs. The infected limbs will turn brown and then black at the tips, eventually progressing into the tree and killing it. The affected bark becomes sunken and eventually becomes dry and may have cracks at the edge of the area. A very distinct symptom of fire blight is the end of the branch may bend over like a shepherd's crook. You may not see the crook at every branch, but the majority of them will have this symptom. Dead leaves and fruit remain on the tree and branches, and may ooze a dark sap.

Fire blight is often spread by insects. The insects carry the bacteria from infected to healthy plants, and the bacteria enter the plant through the flowers. The bacteria can also enter through wounds on the plant.

The main control for this disease is to plant resistant varieties. Some ornamental pears are not very resistant to fire blight. They grow well until the disease finds them and then they get infected. Resistant varieties either will not get the disease or will survive once they get the disease.

I highly advise homeowners to prune out the infected branches with pruning shears. You must be careful when doing this, as it is easy to spread the disease from branch to branch. The best method to reduce spread is to clean your shears with rubbing alcohol for disinfection. This can be accomplished by wiping the shears with an old t-shirt or cloth.

Do not fertilize heavily with nitrogen as this may make the disease worse. Be careful about damaging the tree since the disease can enter through wounds. Once the tree is infected, it is difficult to control.

Chemical Control Chemical controls are generally not very effective once the disease is in the tree. Copper sprays are labeled to prevent the disease. They must be sprayed before the tree is infected and must be used every several days during bloom. However, these Copper spraying requirements I just described can be involved and will require major effort.

If you have further questions on fire blight, please do not hesitate to call the Jenkins County Extension Office.