Diseases of Bradford Pear Trees

Bradford pears are a popular ornamental tree found in cities across the United States. The biggest problem with the species is its weak branches and relatively short life span. The trees may also suffer from fire blight or entomosporium leaf spot, both diseases that can kill the tree if left untreated.

Identification

The Bradford pear, a spring-flowering tree, is a native of China. The tree grows to between 30 and 50 feet tall and 20 to 30 inches wide. It grows quickly, with a 12- to 15-foot increase over a period of eight to 10 years. The tree has a short life span of 15 to 25 years.

Fire Blight

Fire blight is a common Bradford pear problem. With this disease, the ends of twigs and leaves turn black, and the disease is very difficult to control. Fire blight is caused by a bacterium and can spread quickly. Blossoms, stems, leaves and fruit can all be affected.
Symptoms of fire blight begin in early spring when the weather is humid or rainy. The disease moves down branches, killing young twigs and blackening leaves. Cankers start to show up on branches. When it's rainy, a milky, sticky liquid may be seen oozing from infected trees. Fire blight is spread by rain and insects.
There is no cure for this disease, so prevention is the key. Make a point of planting tolerant types of Bradford pears and use insecticides and bactericides. Use strephtomycin, and as soon as blossoms open, apply the first spray and repeat every four to seven days while blooms are present.

Entomosporium Leaf Spot

This disease causes reddish-purple leaf spots that grow, creating a reddening effect on the leaves. If not treated, the disease will cause leaf-drop. This fungus is usually found during fall and spring when the weather is rainy and cool.
To control the disease, prune red tips in the winter. Pruning during the growing season means new growth, which is at risk for fungal attack. Discard fallen and infected leaves.
Use fungicides to get rid of leaf spot. Use the spray at the first sign of the disease and reapply every week to two weeks. Use fungicides or pesticides labeled for entomosporium leaf spot.

Branch Splitting

This is one of the Bradford's biggest problems and the reason why many caution against planting the species. The upright branches that give the Bradfords a nice shape also cause weak branches, especially in older trees. Heavy winds, ice or snow accumulation can cause limbs to break and branches to split. Worse, the damage usually causes entire sections to fall and disfigures the entire tree.

Insect Damage

Generally, Bradford pears aren't susceptible to insect problems. However, the trees sometimes experience insect issues, including a webworm invasion. If you see worms and webs in the tree, remove the webs in the evening hours. Use a spray such as Sevin if worms are still small.

References

• Clemson University Extension Office
• Mississippi State Extension Service
• Bradford Pear Problems

Resources

• Bradford Pear and Webworm