DISEASE: Aster yellows
HOST: Squash
Diagnostic characteristics for the disease are yellowing of young leaves, proliferation of secondary shoots, and rigid erect habit. Leaves are misshapen and smaller than normal and have stiff, thick laminae.

Aster yellows | Squash
DISEASE: Aster yellows
HOST: Squash (Cucurbita sp.)
PATHOGEN: 'Candidatus Phytoplasma asteris'
PATHOGEN SYNONYM: Phytoplasma Aster yellows group
SOURCE: S. Miller
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: Bacterial canker
HOST: Tomato
Necrosis of leaf margins is early symptom of disease.

Bacterial canker | Tomato
DISEASE: Bacterial canker
HOST: Tomato (Lycopersicon esculentum)
PATHOGEN: Clavibacter michiganensis subsp. michiganensis
PATHOGEN SYNONYM: Corynebacterium michiganense
SOURCE: S. Miller
DISEASE: Bacterial canker
HOST: Tomato
Leaves with interveinal necrosis.

Bacterial canker | Tomato
DISEASE: Bacterial canker
HOST: Tomato (Lycopersicon esculentum)
PATHOGEN: Clavibacter michiganensis subsp. michiganensis
PATHOGEN SYNONYM: Corynebacterium michiganense
SOURCE: D. Ingram
DISEASE: Bacterial canker
HOST: Tomato
Leaves with papery, gray necrotic areas around green veins.

Bacterial canker | Tomato
DISEASE: Bacterial canker
HOST: Tomato (Lycopersicon esculentum)
PATHOGEN: Clavibacter michiganensis subsp. michiganensis
PATHOGEN SYNONYM: Corynebacterium michiganense
SOURCE: D. Ingram
DISEASE: Bacterial canker
HOST: Tomato
Sliced stem with yellowish brown discoloration of vascular tissues.

Bacterial canker | Tomato
DISEASE: Bacterial canker
HOST: Tomato (Lycopersicon esculentum)
PATHOGEN: Clavibacter michiganensis subsp. michiganensis
PATHOGEN SYNONYM: Corynebacterium michiganense
SOURCE: S. Miller
DISEASE: Bacterial canker
HOST: Tomato
Advanced stage of disease with reddish brown discoloration of vascular tissues (bottom). Healthy stem (top).

Bacterial canker | Tomato
DISEASE: Bacterial canker
HOST: Tomato (Lycopersicon esculentum)
PATHOGEN: Clavibacter michiganensis subsp. michiganensis
PATHOGEN SYNONYM: Corynebacterium michiganense
SOURCE: D. Ingram