Fireblight in Resistant Apple Varieties
Because I have cedars and thus cedar apple rust in my area I have planted several resistant varieties. Coincidentally these apple varieties are also listed as either resistant or highly resistant to fireblight. Last year (trees 7 years old) fireblight showed up on several of the trees (Williams Pride, Redfree and Liberty). I followed the recommended procedure of cutting the dead parts and marking the ends with spray paint and then removing a foot or so of the branch below the spray paint. I noticed in every case once I pruned the dead areas off, a bunch of new growth sprouted from the end of the remaining branches - that new growth got cut off when the secondary pruning removed the spray painted branches. My question is should I use an alternate pruning method to control fireblight in highly resistant apple varieties so as not to remove new growth?
Unfortunately, resistant does not mean immune. If weather conditions are good, resistant varieties can be infected.
If pruning off entire infected branches and trying to replace them and you see new shoots that is fine. However, if what you cut off is a scaffold limb, then you need to select a new shoot and train it to become a scaffold branch.
If you continue to notice fireblight, you may need to eventually consider removal in the future.