I've had good success with fighting pm outdoors with this
BIOPROTEC 31-172 Fongicide and Bactericide for Tomato and Garden
https://www.amazon.ca/gp/product/B07R1X8XHD
I use it at 8% mix so a 500ml bottle makes 5.75L of solution.
It's basically lactic and citric acids. Doesn't seem to harm the...