I was recently at a local vineyard and was walking by the vines and noticed they had powdery mildew. If you look closely at the picture, you see the white on the green leaves. Yup..that’s a case of powdery mildew. Powdery mildew shows itself on the top surface of the leaves.
If left untreated, severe infection can lead to high crop losses and may also be detrimental to final wine quality.
If you are visiting a local winery and stroll through the vineyard and see leaves such as this, you know what it is.