Gardening and Horticulture - Black Knot Fungus

We have a rather large Canadian Cherry tree planted in our backyard. This tree has what I believe is called Black Knot fungus; a gnarly looking dark growth that can be up to a foot long and grows around or at the end of branches. Every year this problem has gotten worse, even though we have tried to prune to remove these growths. This fungus is most noticeable after all the leaves have fallen. I am afraid that if this continues we will lose the tree. I have come to understand that this fungus is chronic with this type of tree but was hoping there was a treatment or some type of simple solution to this problem.

Here is a rather complete document on this disease and its control.

http://web.aces.uiuc.edu/vista/pdf_pubs/809.pdf

Hope this helps.