I was planning to treat one of my Japanese black pines with bonide infuse, (a systemic fungicide) to treat needle cast. I was also planning on using daconil and copper fungicide to treat it. I do not know if I should treat with bonide infuse, since it could harm mycorrhizae. Does anyone use systemic fungicides on Japanese black pine soil without it having negative effects? Should I apply it only once or twice each growing season to minimize mycorrhizal damage?