It will need a copper and a fungicide, also watch out for frosts and birds.

I have an organic fungicide that I have sprayed on our Apple trees but I’m not sure if it actually works. What’s the copper?

Copper is also a fungicide and depending on the exact formulation and what it might be blended with, is often considered organic as well.

If the majority of the tree is healthy I would just prune out the wilted branch. i wouldn’t spray the tree with anything it is not fruiting and going dormant soon the leaves will turn ugly and drop. Check your local county extension for spray recommendations for your area every place is different. Also Rainer is not self fertile hopefully you have a pollinator tree for it

I trimmed that part off so we will see what happens in the spring. We have a bing tree as well so I think that is a pollinator for it.