eastern filbert blight

Symptoms

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.

Plants affected

• European hazelnut

Easily confused with

• bacterial blight of hazelnut

  How to tell them apart: Eastern filbert blight (a fungus). Look for elongated, sunken cankers along branches and stems that carry rows of distinctive black, rough, football-shaped (oval) erumpent stromata bursting in lines through the bark — this is the decisive sign. Cankers expand year over year and girdle limbs, killing whole branches above them; foliage on affected limbs wilts and dies back. The black stromatic rows are absent in bacterial blight and are diagnostic for EFB. Bacterial blight (a bacterium). Look for small angular brown-to-black leaf spots, often with a yellow halo and confined by leaf veins, plus dark water-soaked sunken lesions on green shoots, petioles and buds; infected buds turn brown and fail to open. Twig and shoot lesions are smooth and dark without any raised black stromata, and damage is worst in cool wet spring weather. The absence of erumpent black football-shaped fruiting bodies separates it from EFB.

• hazelnut powdery mildew

  How to tell them apart: Anisogramma anomala (Eastern Filbert Blight) attacks the WOODY parts: look for distinct rows of hard, raised, black-to-dark-brown football-shaped bumps (stromata) erupting in lines through the bark of branches and twigs, often on one side, with branch dieback above the cankered zone. It does NOT make a powder. Phyllactinia guttata (hazel powdery mildew) attacks the LEAVES: a thin white-to-greyish powdery or felt-like film, mainly on the underside of leaves, that you can rub off with a finger; late in the season tiny dark dot-like fruiting bodies appear in the felt. The decisive test: black hard rows on the stem that cannot be rubbed off = the quarantine fungus; soft white dust on leaves that wipes away = the common mildew.

Common questions

How do I recognise eastern filbert blight on European hazelnut?

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.

Do I have to report eastern filbert blight?

Yes. eastern filbert blight is a regulated quarantine organism in the EU. A suspected finding must be reported to your national plant protection organisation — they will confirm it and tell you what to do next.

How is eastern filbert blight treated?

Mainly with biological and cultural measures — removing affected material, changing the conditions that favour it, and treating with agents approved in your country. The exact steps and their timing depend on the plant, the season and where you live: Dr. Phyto works them out in a free diagnosis.