DISEASE: Bacterial blight (Brown stem)
HOST: Celery
Lesions are necrotic and circular to angular. Some have yellowish halos. Older lesions become brown and dry.

Bacterial blight (Brown stem) | Celery
DISEASE: Bacterial blight (Brown stem)
HOST: Celery (Apium graveolens)
PATHOGEN: Pseudomonas cichorii
SOURCE: R. Raid
DISEASE: Bacterial blight (Brown stem)
HOST: Celery
Ooze from lesion on celery leaf.

Bacterial blight (Brown stem) | Celery
DISEASE: Bacterial blight (Brown stem)
HOST: Celery (Apium graveolens)
PATHOGEN: Pseudomonas cichorii
SOURCE: R. Raid
DISEASE: Bacterial blight (Brown stem)
HOST: Celery
Characteristic brown discoloration of petioles, which is more evident on inside of petiole close to the crown. Parenchyma tissues are firm and brown.

Bacterial blight (Brown stem) | Celery
DISEASE: Bacterial blight (Brown stem)
HOST: Celery (Apium graveolens)
PATHOGEN: Pseudomonas cichorii
SOURCE: K. Pernezny
DISEASE: Dogwood stunt
HOST: Dogwood
Diseased plant with small leaves (left).

Dogwood stunt | Dogwood
DISEASE: Dogwood stunt
HOST: Dogwood (Cornus sp.)
PATHOGEN: 'Candidatus Phytoplasma asteris'
PATHOGEN SYNONYM: Phytoplasma Aster yellows group
SOURCE: W. Sinclair
DISEASE: Shallow bark canker
HOST: Walnut
Diseased, discolored tissues revealed by removing external bark.

Shallow bark canker | Walnut
DISEASE: Shallow bark canker
HOST: Walnut (Juglans regia 'Hartley')
PATHOGEN: Brenneria nigrifluens
PATHOGEN SYNONYM: Erwinia nigrifluens
SOURCE: B. Teviotdale
DISEASE: Shallow bark canker
HOST: Walnut
Trunk with brown exudate shallow cankers.

Shallow bark canker | Walnut
DISEASE: Shallow bark canker
HOST: Walnut (Juglans regia 'Hartley')
PATHOGEN: Brenneria nigrifluens
PATHOGEN SYNONYM: Erwinia nigrifluens
SOURCE: B. Teviotdale