DISEASE: Aster yellows
HOST: Potato
Chlorotic and stunted foliage with necrotic leaf margins. Other symptoms may be phyllody, virescence, purple or yellow pigmentation, and rolling of leaflets.

Aster yellows | Potato
DISEASE: Aster yellows
HOST: Potato (Solanum tuberosum)
PATHOGEN: 'Candidatus Phytoplasma asteris'
PATHOGEN SYNONYM: Phytoplasma Aster yellows group
SOURCE: S. Thomson
DISEASE: Aster yellows
HOST: Potato
Stunted, chlorotic plants (left) with stiff, rolled leaves.

Aster yellows | Potato
DISEASE: Aster yellows
HOST: Potato (Solanum tuberosum)
PATHOGEN: 'Candidatus Phytoplasma asteris'
PATHOGEN SYNONYM: Phytoplasma Aster yellows group
SOURCE: S. Thomson
DISEASE: Aster yellows
HOST: Potato
Diseased plant with malformed tubers.

Aster yellows | Potato
DISEASE: Aster yellows
HOST: Potato (Solanum tuberosum)
PATHOGEN: 'Candidatus Phytoplasma asteris'
PATHOGEN SYNONYM: Phytoplasma Aster yellows group
SOURCE: S. Thomson
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 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