303 Palouse, Wenatchee, Washington, 98801. Cutting Fire Blight in a Wenatchee area Bartlett orchard, June 2, 1997. Cutting blight strikes takes a keen eye and a cold heart if you expect the process to effectively reduce further damage to the infected tree. The blight bacteria move toward the trunk from the visible strike.
Bacteria are present well ahead of the symptoms.
The amount of wood you must remove depends on the vigor of the wood affected and the variety of the tree. Over all, it is better management to cut more than you actually needed to, but to cut only once to remove the blight. Pears must be cut harder than apples. However, this very much depends on the age, variety, rootstock and vigor of the tree in trouble. However, the danger to young trees is considerable.