Tom Jaszewski wrote:

There IS good data on milk as a control.

1 part milk and 9 parts water. Whey proved to be more effective. I
spray with a mist blower and get adequate control on ornamentals.

Do you have any idea if milk has any effect on other fungus such as black
rot or downy mildew. I have read that it is only good on Powdery mildew
but would like some feedback if others have had success with other fungus.