I have a small backyard with many variety of trees. Recently I found that some of my plums and cherry trees has black knot fungus. While searching for an remedy I came across an article http://infinitygardens.ca/blog/black-knot-fungus-on-mayday-trees-and-schubert-chokecherries/ which had few solutions like pruning and drip irrigation. I tried them , but it was not very efficient. My trees still have fungal disease. So I need some suggestions from you guys to get rid of this fungus. Any suggestions are greatly appreciated.. Thanks in advance.