Plant Protection - Fire Blight
Fire Blight is a serious disease of apples, pears, and other members of the Rose Family. It is caused by a bacterial infection of Erwinia amylovora.
Symptoms of infection include a browning and blackening of young leaves and twigs. Often the end of the branch bends down like a shepherd's crook; the leaves die but do not drop off. This disease can spread rapidly and can kill entire branches, or if unchecked, an entire tree.
The fire blight bacteria overwinters in cankers on the bark and becomes infectious during warm spring rains. Water, bees, and other insects frequently carry the bacteria from one tree to another during the spring, spreading the infection.
For homeowners, chemical control is normally not warranted. Diseased branches may be pruned out of the tree. Blighted branches should be cut 10 to 12 inches below the diseased portion. Sterilize pruning shears with household bleach between cuts. A solution using 9 parts water with 1 part bleach (for example, ¼ cup bleach to 2 ¼ cups water) should be used for sterilizing shears. Burn or bury blighted branches.
Fire blight spread between trees can be reduced by applications of products that contain streptomycin sulfate as the active ingredient. These products are available under various trade names and may be purchased at most garden supply stores. To obtain best disease control with fire blight spray, the first applications should be made at the start of the bloom period, and every five to seven days thereafter. For additional information on use of fire blight spray material, refer to product labels.
To help your trees be less susceptible to this blight, try to plant blight resistant varieties. Avoid heavy fertilization since this produces long succulent shoots which are more readily attacked by the disease. Avoid planting close to wild plants of hawthorn, apple or pear. Prune out and destroy all blighted branches as they appear.
READ AND FOLLOW ALL LABEL DIRECTIONS AS IMPROPER USE OF PESTICIDES MAY AFFECT ANIMAL AND HUMAN HEALTH.
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