Epidemiology and Management of Hop Pests and Diseases

Powdery Mildew Risk Index1. If greater than 6 continuous hours above 86°F,subtract 20 points, else;2. If greater 0.1” rain, subtract 10 points,else;3. If greater than 6 continuous hours above 86°Con previous day, then no change in the index,else;4. If at least six continuous hours between 60-81°F, then add 20 points, else;5. If none of the above rules apply, then subtract10 points.