Tidying up around base of weeping cherry and found this wound. I think this has opened up quickly and over winter. Thing is its about to burst into blossom, and is otherwise on fine form. Its about 10m away from an apple tree that has canker: which I am trying to sort out. What caused this, and any possible treatment?
It was caused by a canker-type disease, such as bacterial canker or brown rot, but is trying to heal itslef, having isolated the rot.
This is not unusual in cherry trees, sometines they survive, sometimes not. Just take away the loose bark and allow air to keep the area dry. Do not cover with anything.