Can you recognize this disease?

Hi, I know that with permaculture everything is kept in balance, but I just started, so I thought I'd take advantage of you guys's vast knowledge to see if I can correct this problem with my zinnias.
I looked online last year. At first I thought it was powdery mildew, now I'm not sure. I've been treating it with baking soda, neem oil, hydrogen peroxide, vinegar water, but never systematically. Bottom line, it keeps coming back and spreading. Any clue? Thanks!

Ok it looks like I solved my own problem.
At least on some younger zinnias that I have elsewhere, the fungus seems under control after alternate spraying of vinegar water and hydrogen peroxide water.
At first it seemed not to work, but actually since my posting here I haven't had to spray again.
Also, I just pruned the older zinnias. It seems that with permaculture you already have to start perfect, because you can't really chop and drop vegetable material that's diseased.
So, I guess I just created waste.
I do have a bag of tightly packed grass and weed clippings that I sprayed lightly with milk whey. I haven't opened the bag yet to see the result. Maybe if I add the zinnia clippings to other weeds and spray them like that, the lactobacilli will have the upper hand on any pathogen.