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: Bacterial blast and black pit
HOST: Citrus (Lemon)
The term "black pit" refers to black lesions on fruit, which may be specks or large, sunken pits as seen here. They also may be light tan, later becoming reddish brown to black.

Bacterial blast and black pit | Citrus (Lemon)
DISEASE: Bacterial blast and black pit
HOST: Citrus (Lemon) (Citrus limon)
PATHOGEN: Pseudomonas syringae pv. syringae
SOURCE: J. Menge
DISEASE: Bacterial blight
HOST: Bean
Bean leaves with large necrotic areas.

Bacterial blight | Bean
DISEASE: Bacterial blight
HOST: Bean (Phaseolus vulgaris)
PATHOGEN: Xanthomonas axonopodis pv. phaseoli
PATHOGEN SYNONYM: Xanthomonas campestris pv. phaseoli
SOURCE: J. Young
DISEASE: Bacterial blight
HOST: Bean
Field of severely diseased beans.

Bacterial blight | Bean
DISEASE: Bacterial blight
HOST: Bean (Phaseolus vulgaris)
PATHOGEN: Xanthomonas axonopodis pv. phaseoli
PATHOGEN SYNONYM: Xanthomonas campestris pv. phaseoli
SOURCE: M. Shurtleff
DISEASE: Bacterial blight
HOST: Bean
Close-up of necrotic leaf lesions.

Bacterial blight | Bean
DISEASE: Bacterial blight
HOST: Bean (Phaseolus vulgaris)
PATHOGEN: Xanthomonas axonopodis pv. phaseoli
PATHOGEN SYNONYM: Xanthomonas campestris pv. phaseoli
SOURCE: A. Alvarez
DISEASE: Bacterial blight
HOST: Bean
Bean leaflet with large necrotic lesions surrounded by chlorotic zones.

Bacterial blight | Bean
DISEASE: Bacterial blight
HOST: Bean (Phaseolus vulgaris)
PATHOGEN: Xanthomonas axonopodis pv. phaseoli
PATHOGEN SYNONYM: Xanthomonas campestris pv. phaseoli
SOURCE: I. Hubbeling, J. van der Wolf
DISEASE: Bacterial blight
HOST: Bean
Seed infested with blight bacteria and insects. Bacterial blight is predominately seedborne.

Bacterial blight | Bean
DISEASE: Bacterial blight
HOST: Bean (Phaseolus vulgaris)
PATHOGEN: Xanthomonas axonopodis pv. phaseoli
PATHOGEN SYNONYM: Xanthomonas campestris pv. phaseoli
SOURCE: L. Claflin