Safe to get scion from apple tree with fireblight ?
I have a couple dwarf apple trees which got fireblight this year and you can still see the dark section of bark on the tree trunk and a couple branches (where it struck) although the trees appear to be healthy and growing with plenty of nice green leaves. Is it safe to take a scion from these trees and graft to other apple trees which have not shown signs of fireblight? Or are just about any tree disease systemic and thus grafting a piece to another tree would put it at risk as well?
My experience with fireblight on apple trees is that once it hits the main trunk, the following year it generally spreads throughout the tree eventually killing it and or it spreads to other healthy apple trees. I have butchered a couple small trees to remove all fireblight, and they seem to be recovering, but will remove them if fireblight reappears.
Same logic apply to for example a cherry tree with bacterial canker or a peach tree with peach leaf curl?