Anyone familiar with black rot canker in apples?
We have an older apple tree that appears to be dying of black rot canker. I've been able to find a lot online about prevention and management of the disease, but in this case the infection is on the main trunk and surrounds the tree and its branches, so I'm guessing that means the tree cannot be saved since there would be no way to cut the infected wood out. (We didn't recognize the canker for what it was until the tree began yellowing/dying off on several branches early this month; the canker has been there in some state for at least the past five seasons, though this is the first year we have seen any sign of stress in the tree itself and we always get bushels of apples.)
I'm trying to figure out:
- Is black rot canker a threat to other types of fruit trees, specifically cherries, plums, or persimmons? We have a number of trees in close proximity to the infected apple and are trying to figure out if the spores may infect them as well, and if so what precautions we need to take beyond things like cleaning pruning tools.
- Assuming this canker is limited to apples, is it okay to go ahead and leave the tree there until it dies of its own accord? Should we prune out the branches that are dying off even with the infection on the main trunk, or is that not going to make a difference one way or the other?
- And last but not least, I know this disease is spread by spores...does this mean we can't plant another apple near the spot where the old tree was? Any ideas on how far away would be safe? (We're in an urban area on a tenth of an acre, so space is limited!)
Thank you for any advice or thoughts!