Powdery mildew is the bane of my cucurbits. I get it every year on nearly all of my plants, and by the end of September most of the patch is dead or dying. I get pumpkins, but I'm thinking I could get more and bigger and more bigger pumpkins if I could control it.
So this year I bought a 4 gallon backpack sprayer and a bottle of Serenade organic fungicide for $13.22. The suggested dilution ratio for fruits and vegetables is 1/2 C per gallon of water, so about 2 cups to fill the sprayer. I ran the sprayer dry twice covering the entire pumpkin patch, so I used half a bottle of Serenade, or about $6.61 worth.
I've read that a dilute solution of milk is effective as a preventative, but not as a cure, so I figure I'd alternate Serenade with milk. Suggested water:milk ratios are all over the place as 2:1, 3:1, 9:1, etc., so I figured I'd try 7:1, or half a gallon of milk to 3.5 gallons of water to fill my sprayer. I did this twice, which cost me one gallon of milk, which is about $3.70 here in Los Angeles.
Given that milk is only effective if I don't already have an infection, and that I'm using a dose at the lower end of effectivity, it doesn't seem like I'm saving that much money with milk vs. Serenade.
Has anyone used powdered, dry milk for this? It's probably quite a bit cheaper than whole milk, though I haven't bought any powdered milk in decades.