Question and Answer Q. We discovered fire blight on one of our
apple trees this summer. We cut all the branches with symptoms
(withered leaves and the crook at the end) and burned them. We
have seen no sign of any further damage. Do we still need to
spray next spring as directed by the product we bought from our
local nursery? A. Fireblight is a bacterial disease that affects
over 70 members of the Rose Family (Rosaceae), including
ornamental and fruiting apples and pears. Cultural practices can
help prevent further spread of the disease. When removing
diseased limbs, you should prune only in dry weather and make
cuts at least 12 inches below the infection so that the cut is
made in healthy tissue. These cuts should be delayed late enough
into summer that the new growth has completed for the season. Be
sure to sterilize your pruning tools between cuts. Delay any
major pruning jobs until late winter while trees are dormant.
There are some helpful photos and description of the symptoms at
http://www.ppdl.purdue