Dr. Phyto

European hazelnut

Corylus avellana

Diseases & pests on this plant

• hazelnut weevilCurculio nucum

  Small (1-2mm) perfectly circular exit hole in nut shell, kernel inside partly or completely eaten + filled with frass, infested nuts drop prematurely in summer, adult weevils visible on foliage in spring (7-8mm with long curved snout), pest pressure builds up over 2-3 seasons if not managed.

• bacterial blight of hazelnutXanthomonas arboricola pv. corylina

  Angular brown leaf spots with yellow halos, dark sunken cankers on twigs + young branches with bacterial ooze in spring, branch dieback + tip flagging, dark spots on developing nut husks sometimes penetrating kernels, young nursery trees can be killed outright in heavy infections.

• hazelnut powdery mildewPhyllactinia guttata

  Powdery white coating on undersides of older leaves from August onward, upper leaf surfaces develop yellow blotches, severely affected leaves dry + drop early, fluffy white mycelium with embedded dark cleistothecia in late autumn, young nursery trees stunted in heavy infections.

• eastern filbert blightAnisogramma anomalaEU-notifiable quarantine organism

  Distinctive linear rows of black football-shaped stromata along branches (1-3cm long, looking like rows of beans), branch cankers slowly expand + girdle limbs over 2-4 years killing them, infected trees gradually decline + die within 5-10 years of first symptoms, no fruit symptoms but progressive yield collapse.