Fruit tree grafting

Hello,

 I have a pear tree that has fire blight. Would it be wise to cut it and graft a blight resistant variety onto the root stock?
Or should I cut it down completely and plant a resistant tree?

I bought two pear trees at the end of the session a couple of years ago from a farm store. They grew well. Two years
ago one tree had it, so I cut it back pretty hard. Seemed to help until this year. The other tree is clapps favorite which has
fire blight. I cut a by of it off earlier this year but it continued to spread through the tree. Not sure if either are grafted onto
root stock or not. I assume most trees are these days. Are root stock susceptible to fire blight? I live in Indiana. Wet springs.

Any thoughts or advice about this would be helpful.

Thanks
Pete

The OHF line of pear rootstocks were developed for their resistance to fire blight, and they are among the more commonly used rootstocks. So, your rootstock might be immune and they might not be.

If fireblight is a major problem in your area, it's probably best to just replant with resistant rootstock and resistant cultivars. This PDF should give you some ideas.
https://www.extension.purdue.edu/extmedia/BP/BP-30-W.pdf

I have lost four pear trees. Replanting with disease resistant varieties is probably best. You might even try another kind of fruit tree. I replanted with one pear and several other types of fruit. Apples can get fireblight too. There are some resistant varieties though.

It can affect the roots.

Are you sterilizing your pruning shears between each cut? If not, you could be spreading it.