DISEASE: Ash yellows
HOST: Ash
Ash sapling with basal sprouts and chlorotic leaves.
Ash yellows | Ash
DISEASE: Ash yellows
HOST: Ash (Fraxinus pennsylvanica)
PATHOGEN: 'Candidatus Phytoplasma fraxini'
PATHOGEN SYNONYM: Phytoplasma Ash yellows group
SOURCE: W. Sinclair
DISEASE: Ash yellows
HOST: Ash
Witches'-broom at base of declining tree.
Ash yellows | Ash
DISEASE: Ash yellows
HOST: Ash (Fraxinus velutina)
PATHOGEN: 'Candidatus Phytoplasma fraxini'
PATHOGEN SYNONYM: Phytoplasma Ash yellows group
SOURCE: W. Sinclair
DISEASE: Ash yellows
HOST: Ash
Forest of declining trees, some chlorotic and others with dieback.
Ash yellows | Ash
DISEASE: Ash yellows
HOST: Ash (Fraxinus americana)
PATHOGEN: 'Candidatus Phytoplasma fraxini'
PATHOGEN SYNONYM: Phytoplasma Ash yellows group
SOURCE: W. Sinclair
DISEASE: Ash yellows
HOST: Ash
White ash with deliquescent branching.
Ash yellows | Ash
DISEASE: Ash yellows
HOST: Ash (Fraxinus americana)
PATHOGEN: 'Candidatus Phytoplasma fraxini'
PATHOGEN SYNONYM: Phytoplasma Ash yellows group
SOURCE: W. Sinclair
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 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