Disease Management
Mildew is one of the biggest challenges for growers in the Northeast. The scouting of yards should be performed weekly during the growing season and a spray plan should be made accordingly.
Powdery and Downy Mildew of Hops
Key Differences and Similarities in Managing the Mildews
Webinar: Differences in Mildews
Downy Mildew
The most characteristic symptom of the disease in hops is the presence of systemically infected shoots, called “spikes”. This tissue arises from either the hop crown (primary spikes) or from meristems (secondary spikes). The bines are stunted with short internodes in both cases and possess brittle, downward curling, chlorotic leaves.
Considering Varietal Resistance to Downy Mildew
Powdery Mildew
Deep Dive – Hop Powdery Mildew: Identification and Management
Powdery mildew can occur on all green tissue of the hop bine, including the stems, leaves, flowers, and hop cones. The most telling sign of the pathogen is white, powdery colonies that can be found on either side of leaf tissue, as well all other plant parts.Infections on the underside of the leaf are also possible, and the host plant usually expresses chlorotic spots on the corresponding topside of the leaf as a symptom.
Halo Blight
Halo blight is a new fungal disease first identified in NY hopyards. Leaf symptoms are large, necrotic patches with a chlorotic halo. The disease is associated with significant yield loss through cone shattering.
First Report of Halo Blight on Hop Caused by Diaporthe humulicola in New York
If you see a disese or pest in your yard that you need help identifying, contact the Cornell Plant Diagnostic Clinic.
Common Insect Pests in Hops
Potato Leaf Hopper
Potato Leaf Hopper – Michigan State Extension
Two-Spotted Spider Mite
Hop-Spider mite | Pacific Northwest Pest Management Handbooks (pnwhandbooks.org)
Hop Aphid
Hop-Hop aphid | Pacific Northwest Pest Management Handbooks (pnwhandbooks.org)
Lepidoptera