DISEASE: Aster yellows
HOST: Barley
Infection by this phytoplasm causes twisted awns and sterile florets.

Aster yellows | Barley
DISEASE: Aster yellows
HOST: Barley (Hordeum vulgare)
PATHOGEN: 'Candidatus Phytoplasma asteris'
PATHOGEN SYNONYM: Phytoplasma Aster yellows group
SOURCE: E. Banttari
DISEASE: Aster yellows
HOST: Barley
Small necrotic spots on lower leaves and red coalescing streaks on upper leaves.

Aster yellows | Barley
DISEASE: Aster yellows
HOST: Barley (Hordeum vulgare)
PATHOGEN: 'Candidatus Phytoplasma asteris'
PATHOGEN SYNONYM: Phytoplasma Aster yellows group
SOURCE: E. Banttari
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: Grass
Timothy grass with light-colored lesions caused by unidentified Xanthomonas sp.

Bacterial blight | Grass
DISEASE: Bacterial blight
HOST: Grass (Phleum pratense)
PATHOGEN: Xanthomonas sp.
SOURCE: M. Shurtleff
DISEASE: Bacterial kernel blight (Leaf blight)
HOST: Barley
Dark, brown discolored kernels at the embryo end and posterior surface.

Bacterial kernel blight (Leaf blight) | Barley
DISEASE: Bacterial kernel blight (Leaf blight)
HOST: Barley (Hordeum vulgare)
PATHOGEN: Pseudomonas syringae pv. syringae
SOURCE: C. Martinez-Miller
DISEASE: Bacterial leaf blight
HOST: Barley
Diseased barley plants with typical bleaching of flag leaves. Initial symptoms are water-soaked lesions that later coalesce. Eventually, the entire leaf becomes necrotic and edges roll inward.

Bacterial leaf blight | Barley
DISEASE: Bacterial leaf blight
HOST: Barley (Hordeum vulgare)
PATHOGEN: Pseudomonas syringae pv. syringae
SOURCE: D. Sands
DISEASE: Bacterial leaf streak and stripe
HOST: Grass
Vasey grass with yellowish to brownish red streaks and stripes.

Bacterial leaf streak and stripe | Grass
DISEASE: Bacterial leaf streak and stripe
HOST: Grass (Paspalum urvillei)
PATHOGEN: Acidovorax avenae
PATHOGEN SYNONYM: Acidovorax avenae subsp. avenae
SOURCE: R. Gitaitis
DISEASE: Bacterial stripe
HOST: Grass
Sudangrass with dark reddish stripes on leaves.

Bacterial stripe | Grass
DISEASE: Bacterial stripe
HOST: Grass (Sorghum bicolor)
PATHOGEN: Burkholderia andropogonis
PATHOGEN SYNONYM: Pseudomonas andropogonis
SOURCE: E. Hansen, M. Shurtleff
DISEASE: Bacterial wilt
HOST: Grass
Initial symptom is a lime-green, yellow, or blue-green appearance of the grass. The next symptom is small, reddish brown spots on leaf blades.

Bacterial wilt | Grass
DISEASE: Bacterial wilt
HOST: Grass (Poa annua)
PATHOGEN: Xanthomonas translucens pv. poae
SOURCE: P. H. Dernoeden