Not fireblight.I happen to have currently a 20 feet high Comice tree with firebligh braught likely by insects or birds from neigborhood backyards with apple and pear trees showing fireblights.Very hard to control in an urban setting beacause people do not know nor take action to stop it.Close to this pear tree I have one Warren pear tree and one Flemish Beauty pear tree. Totally free from fireblight. They must be resistent to fireblight bacteria. You likely have one of the following issuess:fungus mites or lice, soil elememts deficiency or watering issue due to poor drainage. I suggest you take your leaves to a nursery for an expert to diagnose the problem.You also might send to a lab a sample for analysis.Eliminating the first 3 possibilities you might do a drainage test for your soil.The info to do it is in the net.Just google it.The result will give you an idea how to water the tree. Good luck.Jaime.

Some trees are more resistance than others. I have had it in my orchard on a number of trees, yet other trees were not affected. At times I have had fire blight so bad I could see the bacterial ooze dripping off the blossoms. But, as mentioned no infection on other trees. If I felt like I needed to do something, my first action would be to do just what you suggested. I have thought about trying to remove the canker tissue, but never have tried it. Canker blight that overwinter can cause water sprouts to become systemically infected by the fire blight bacteria if its on a nearby overwintering canker. If I cann't remove the whole branch because the canker is on the trunk, I just leave it alone. However, I do spray the trees with Kocide (copper) along wih my dormant oil spray and maybe it helps, but I am not sure it does much for the fire blight. There is a lot of information on fire blight and all of it does not agree. Studies have been done where it has not helped even to cut out the first strikes, just leave it alone until you do your dormant pruning and then cut out the dead branches. I used to put a lot of time and energy into fire blight, but now I take a more casual approach to it. I have had a lot worst looking trees than yours and one time ordered a new tree to take the place of the fire blighted one, just to pick a couple box of apples off of it this summer. I sprayed painted all the strikes with red paint, then pruned out all the branches during my late winter purning. The tree looked like Charlie Brown's Christmas tree, but is now doing well. Go ahead and try what you suggested. Unless you completely girdle the trunk, it should not harm the tree too much. Use it as a learning experience. See what works and what does not work. I have had some trees die from fire blight, replaced them and they again died. Now, I avoid that particular variety.

I see what you mean now. I'll try to get a pic tomorrow and upload it. The tree is beautifully shaped--for a shade tree. Back in early, early spring, I cut out the branches crossing each other, hanging down, growing straight up, etc. The tree then put on new growth like mad. I did the same to the other, much smaller apple tree, which also responded vigorously but also has hardly borne any fruit. This second tree must tend toward biennial bearing. The original tree, however, has fruited out at least as abundantly as last year, when we first moved in. I started spraying this spring, but too late for the plu curculio, which hit both trees hard. This tree, though, has so many fruit, that many, many apples were unscathed. Per Stark Bros, a tree like this could produce 10-20 bushels of apples. If an average bushel has 125 apples, then this tree is within the range. After all this discussion, I believe I'll thin some more, including, perhaps, some of the apples already bagged. Pics to come within a day or so.

Recently planted trees need regular irrigation for the the first 2 years. That leaf damage is combo water shortage and sunburn. See "watering newly planted trees & shrubs" https://www.extension.umn.edu/garden/yard-garden/trees-shrubs/watering-new-trees-shrubs/ Not fireblight because, it it was, the entire tip would look scorched and assume the typical shepherd's crook position. See "trees can get burned with fireblight" https://www.purdue.edu/newsroom/releases/2013/Q2/purdue-expert-trees-can-get-burned-again-by-fire-blight.html