DISEASE: Bacterial blight
HOST: Hazelnut
Diseased young tree with discoloration of the cambium. Dieback of young twigs and branches is characteristic. Other typical symptoms are bud and twig necrosis and small, angular or round, water-soaked leaf spots.

Bacterial blight | Hazelnut
DISEASE: Bacterial blight
HOST: Hazelnut (Corylus americana)
PATHOGEN: Xanthomonas arboricola pv. corylina
SOURCE: J. Pscheidt
DISEASE: Bacterial canker
HOST: Hazelnut
Primary symptoms are failure of buds to break and withering and death of new foliage in spring. Dead leaves remain attached to limbs after normal leaf fall.

Bacterial canker | Hazelnut
DISEASE: Bacterial canker
HOST: Hazelnut (Corylus americana)
PATHOGEN: Pseudomonas syringae pv. avellanae
PATHOGEN SYNONYM: Pseudomonas avellanae
SOURCE: P. Psalidas
DISEASE: Bacterial leaf spot
HOST: Elm
Leaf with small, dark brown lesions and necrosis along veins.

Bacterial leaf spot | Elm
DISEASE: Bacterial leaf spot
HOST: Elm (Ulmus americana)
PATHOGEN: Pseudomonas syringae pv. ulmi
SOURCE: W. Sinclair
DISEASE: Bacterial soft rot
HOST: Wasabi (Japanese horseradish)
Longitudinal sections of diseased rhizomes with discolored vascular tissues.

Bacterial soft rot | Wasabi (Japanese horseradish)
DISEASE: Bacterial soft rot
HOST: Wasabi (Japanese horseradish) (Wasabia japonica)
PATHOGEN: Pectobacterium wasabiae
PATHOGEN SYNONYM: Erwinia carotovora subsp. wasabiae
SOURCE: M. Goto
DISEASE: Bacterial soft rot
HOST: Wasabi (Japanese horseradish)
Longitudinal section of rhizome with discolored vascular bundles (left), and rhizome with external symptoms (right).

Bacterial soft rot | Wasabi (Japanese horseradish)
DISEASE: Bacterial soft rot
HOST: Wasabi (Japanese horseradish) (Wasabia japonica)
PATHOGEN: Pectobacterium wasabiae
PATHOGEN SYNONYM: Erwinia carotovora subsp. wasabiae
SOURCE: M. Goto
DISEASE: Bacterial soft rot
HOST: Wasabi (Japanese horseradish)
Cross section of rhizome with dark, infected vascular bundles.

Bacterial soft rot | Wasabi (Japanese horseradish)
DISEASE: Bacterial soft rot
HOST: Wasabi (Japanese horseradish) (Wasabia japonica)
PATHOGEN: Pectobacterium wasabiae
PATHOGEN SYNONYM: Erwinia carotovora subsp. wasabiae
SOURCE: G. Rodriguez
DISEASE: Elm leaf scorch
HOST: Elm
Diseased tree with scorch at leaf margins.

Elm leaf scorch | Elm
DISEASE: Elm leaf scorch
HOST: Elm (Ulmus americana)
PATHOGEN: Xylella fastidiosa
SOURCE: J. Sherald, M. Shurtleff
DISEASE: Elm leaf scorch
HOST: Elm
Severely diseased tree with dieback and scorched leaves.

Elm leaf scorch | Elm
DISEASE: Elm leaf scorch
HOST: Elm (Ulmus americana)
PATHOGEN: Xylella fastidiosa
SOURCE: W. Sinclair
DISEASE: Elm yellows
HOST: Elm
Symptoms of elm yellows occasionally appear on one branch before others, but more often they involve the entire crown.

Elm yellows | Elm
DISEASE: Elm yellows
HOST: Elm (Ulmus americana)
PATHOGEN: 'Candidatus Phytoplasma ulmi'
PATHOGEN SYNONYM: Phytoplasma Elm yellows group
SOURCE: W. Sinclair