Canker on peach tree
My otherwise-healthy 3-year-old peach tree has developed a nasty-looking canker on the trunk. There are also smaller cankers appearing on some of the branches. I left a plastic trunk guard on it through all of last year, which I'm now realizing was probably a mistake. It hasn't suffered any other damage or stress that I know of. The canker gums a lot in wet weather and seems to clear up in dry hot weather. I don't think it's peach tree borer, since I don't see any sign of sawdust or bits of wood in the gum. I'm thinking it might be cytospora canker, but I'm not sure. Is there anything I can do to help my tree? Is it possible the tree will be able to fight this off and recover? The tree doesn't seem affected so far—it has new growth, leafed out nicely, and set a ton of fruit this year.
Hennepin County Minnesota