Avoid consecutive applications of Priwen fungicide in a season. Alternate applications with fungicides that have a different mode of action and that are also effective on powdery mildew.
Use tank mixes with fungicides from a different group that are effective on powdery mildew when such use is permitted.
Fungicide use should be based on an integrated pest management program that includes scouting, historical information related to pesticide use and crop rotation. Other considerations include host plant resistance, impact or environmental conditions on disease development, disease thresholds, as well as cultural, biological and other chemical control practices.