Evaluation of Fungicides for Hop Powdery Mildew, Study 2, Granger, Washington, 2025

Powdery mildew of hop is caused by Podosphaera macularis. This disease affects all green tissue of the hop plant, forming the characteristic signs of white colonies that bear mycelia and conidia and which lead to browning, shatter, and yield damage when infection occurs on the inflorescence. This report communicates efficacy data of various fungicides against powdery mildew. This trial was conducted on the hop ( Humulus lupulus) cultivar ‘Galena’ during the spring and summer of 2025, near Granger, WA. Results from this trial will help producers develop more effective management approaches for the disease.