Fungicide for black root

Question

What is a good fungicide for cherry trees with black root?

Answer 1

I think you are asking about black knot disease, a common problem especially in wild or untended areas. It is a fungus. One key to control is to prune out all affected branches to prevent further spread. The links below go to articles on black knot of cherry and other fruit trees. Make sure the fungicide explicitly states it treats black knot fungus.
https://www.gardeningknowhow.com/plant-problems/disease/black-knot-tree-disease.htm
https://www.canr.msu.edu/news/controlling_black_knot_in_michigan