On Tue, 21 Jan 2003 22:17:57 GMT, Larry Caldwell
wrote:

I have a couple apple trees infected with fire blight. I want to prune
the diseased limbs off, and know I should disinfect my pruning tools to
keep from spreading the disease to healthy trees.

So what do I use to disinfect the tools? Paint thinner? I have a big
propane burner, but don't want to take the temper out of my tools or melt
fiberglass handles.

You'll get a lot of info he

http://www.ipm.ucdavis.edu/PMG/PESTNOTES/pn7414.html

Removing Diseased Wood
Eliminate fire blight infections by pruning out diseased branches.
Always cut an infected branch at least 8 to 12 inches below the
visible injury or canker. A greater distance below infections may be
required on major branches, scaffolds, or trunks in May or June, when
blight bacteria are moving rapidly. The appearance of new infections
below a pruning cut indicates that the cuts were not made far enough
below the infection and the bacteria had already spread past the
cutting point. If you cut into a canker or infected wood, disinfect
your tool, as described below, to avoid spreading the pathogen.

If a fire blight infection occurs on a trunk or major limb, the wood
can often be saved by scraping off the bark down to the cambium layer
in infected areas (i.e., removing both the outer and inner bark--see
figure). When scraping, look for the long narrow infections that may
extend beyond the margin of the canker or infection site. If any are
detected, remove all discolored tissue plus 6 to 8 inches more at its
front edge. If the limb has been girdled, scraping will not work and
the whole limb must be removed.

To avoid spreading bacteria during pruning, dip or spray the pruning
tool before each cut with a 10% solution of bleach (one part bleach to
nine parts water). Dry and oil tools after use to prevent rust.