Fire blight is not a soil-borne bacteria. It can be effectivley controlled on
smaller trees by using agri-mycin 17, which is basically an antibiotic for
plants. This product is readily available, at least at most of the nurseries I
have visited. You arent going to get 100% control, but you can prevent a good
deal of infection using it. You can also use any number of copper containing
fungicides to help control fire blight, but the agri-mycin works the best. You
can get information about this on the web, there have been a number of fairly
successful trials in different areas of the country, mainly on pears. Of
course, planting resistant varieties is always a good idea as well.

Toad