FYI, poor air circulation is a main cause of powdery mildew. Most people remove the bottom foot of leaves from tomatoes and other plants solely so the air can breathe thru the plant. And that removes unwanted humidity traps.
Powdery mildew does not like alkaline stuff, I don’t usually get any mold on my stuff and I suspect it is from using diatomaceous earth as a soil amendment / supplement. Its calcium so it has an slight alkalinity i assume. I suggest adding a bit of DE to your soil during preparation, or taking a fist sized amount and disperse into 5 gallons water. Then quickly stir and pour so the DE does not settle out of the water solution.
My mammoth melting snow peas got a little powdery mildew this summer but it was wet and they were partially shaded til noon, the other half of the same row was fine. Sometimes its just bad weather that messes stuff up. I kept cursing the weather this summer because high winds kept blowing over my Daikon radish flowers for seed. It is what it is.
The seed company which I will not name but you all have heard of….. I talked to the seed specialist and he said hes never seen pea leaves that big before…….ever.
I told him of my supplements and he said he was going to go get some. lolol
I’m in mold hell near Canada so I’ve had to test a lot of weird stuff. I have to say feeding the plant with certain things, keeping the greenery dry, and proper manicuring for ventilation are the 3 biggest helpful things I was able to do to prevent molds.
Here’s my pea pics for verification