Is copper sulfate organic?
I have a mango tree that was new last year. I've been told that unless you spray the inflorescences with copper sulfate until the mangoes are golf-sized, that there will be no fruit. I decided that I would be satisfied with low yield and did not spray at all. At first there were quite a few mangoes, but as soon as the first summer rain came, the anthracnose and powdery mildew, sooty mold, took over and all rotted and fell. I do want mangoes next year and need to find an organic way to keep them. Every nursery I've asked has recommended copper sulfate products. What do you think?