This article is a list of diseases of hazelnut (Corylus avellana & Corylus spp.).
| Bacterial diseases | |
|---|---|
| Bacterial blight | Xanthomonas arboricola pv. corylina |
| Bacterial canker | Pseudomonas syringae pv avellanae |
| Crown gall | Agrobacterium tumefaciens |
| Fungal diseases | |
|---|---|
| Anthracnose | Piggotia coryli Monostichella coryli Gloeosporium coryli Labrella coryli |
| Armillaria root disease | Armillaria spp. |
| Borro sec | Cryptosporiopsis tarraconensis |
| Cytospora canker | Cytospora spp. |
| Eastern filbert blight | Anisogramma anomala |
| Kernel molds | Mycosphaerella punctiformis [teleomorph] Ramularia sp. [anamorph] Phomopsis spp. Septoria ostryae |
| Kernel spot | Nematospora coryli |
| Leaf blister | Taphrina coryli |
| Leaf spots | Anguillosporella vermiformis Asteroma coryli Cercospora corylina Cercospora coryli Mamianiella coryli Monochaetia coryli Mycosphaerella punctiformis [teleomorph] Ramularia sp. [anamorph] Phyllosticta coryli Ramularia coryli Septoria ostryae Sphaceloma coryli |
| Nectria canker | Nectria ditissima |
| Texas root rot | Phymatotrichopsis omnivora |
| Powdery mildew | Microsphaera coryli Microsphaera ellisii Microsphaera hommae Microsphaera verruculosa Phyllactinia guttata Phyllactinia suffulta |
| Rust | Pucciniastrum coryli |
| Phytoplasmal and spiroplasmal diseases | |
|---|---|
| Filbert Stunt | unknown, suspect a phytoplasma |
| Hazelnut Yellows | phytoplasma |
| Miscellaneous diseases and disorders | |
|---|---|
| Blanks | empty nut shells, cause unknown |
| Brown Stain | brown liquefied portions of shell and kernel, cause unknown |
| Catkin Blast | deformed catkins, cause unknown |
| Sun Scald | high temperature |
| Wet Feet | saturated soil conditions for extended periods. |