Powdery Mildew

[Vinniemac]

I have Marquette and Petit Ami grape vines . What is a good spray for powdery mildew They say there is a slight damage from sulfur spray on both
Vinnie

 

[grapeman]

Potassium bicarbonate is fairly effective for control. Google it and read some papers on it. I have even used baking soda effectively in the past. Now I rely on commercial sprays because they are designed for it in mind.