Apple tree bark disappearing
Hello! Can you help identify what is going on with my dwarf honey crisp apple tree? I recently noticed the bark seems to be eroding away. I've looked online.....is this some type of canker? I have not been doing any spraying. The tree is approximately 5-6 years old (planted ~3 yrs ago) and this spot goes about 1/2 around the tree. I looked the rest of the tree over and the 2nd picture is the only other thing I saw of possible concern....some cracking where the tree was grafted...not sure if this is a concern or not. If you could give your best guess what the first picture is, how to treat it, prevent it....and if this is too far gone and I should replace this tree or is there hope to treat and recover to make it a productive tree. Two years ago it had a bunch of delicious apples. Last year it had only a few blooms and no apples....based on some online reading I assumed it was because I pruned it pretty hard the previous winter. I was hoping for a bounce back year with more delicious honey crisp this year!
I really hate to be the bearer of bad news, but your Honeycrisp's canker is so significant tor the trunk size that it is seriously debilitating the tree and may be the cause of last year's crop failure. Above the cankered area you can see more discoloration as it makes its way up under the bark. The graft is also failing. You should get a new tree this year and plant it elsewhere. You can leave this one in one more year to see if you get some crop. Spraying with copper will slow the disease and may contain its spread through the air. Your other option is to remove this one entirely, but you still need to plant the new one elsewhere. This is a fungal disease.