I have three peach trees which were heavily impacted by mildew last year. We had a good deal of rain on Long Island, NY last year. I sprayed pre-winter and late winter with liquid copper. It worked very well (so far) except for my saturn type peach from Gurney's. It is a beautiful tree but the mildew spray I used seemed totally ineffective. The dark purple leaves are curled and blistering. Meanwhile, the other two trees of a different variety look great.
What can I use on the Flat Wonderful tree from Gurney's that will control mildew?