can I use white vinegar on my apple trees for apple scab
My apples get scab. Can I use vinegar?
Vinegar is sometimes used as a fungicide, but I can't see any reports of its effectiveness against apple scab. Here's some information on apple scab: https://www.gardeningknowhow.com/edible/fruits/apples/treating-apple-scab-fungus.htm
and some information on uses for vinegar: https://www.gardeningknowhow.com/garden-how-to/info/use-vinegar-in-gardens.htm
If you want to use an organic, non-chemical fungicide, perhaps you'd like to try neem oil: https://www.gardeningknowhow.com/plant-problems/pests/pesticides/neem-oil-uses.htm