Yes, If its a fungus it will stay until you kill it, Spray weekly at least for a month then drop off to every two weeks. I use it as a maintenance spray with the dog shampoo for bugs. Small tree should not be a problem to spray. Just spray the entire tree.
I probably should have started spraying a month ago when I noticed the first blossom... but I did spray it today and have it marked down on my calendar when I need to spray again. One more question... do I spray all year long?
Cheryl, I think you need to spray every 10-14 days according to our spray schedule. Your weather is so different from mine that you may have a totally different recommendation. Check with your local extension office ( it will be a county office, call and ask for the number or transfer to them) and get the spray recommendations for your area. good luck, too. I hope you get a decent crop this year. When you see a deformed little apple snip it off. It will get no nicer with time. Thin them to 1 apple every 4" (or a hands width). Unless you want smaller apples, then leave them every 3' apart.
