DISEASE: Aster yellows
HOST: Onion
Infected plants with yellowish, malformed leaves.
Aster yellows | Onion
DISEASE: Aster yellows
HOST: Onion (Allium cepa)
PATHOGEN: 'Candidatus Phytoplasma asteris'
PATHOGEN SYNONYM: Phytoplasma Aster yellows group
SOURCE: R. Rowe
DISEASE: Aster yellows
HOST: Onion
Onion flower with unusual symptoms (left) compared with healthy inflorescence (right). Flowers are distorted and often have abnormally long pedicels. Young leaves may have yellow streaks or a general yellowing of basal portions.
Aster yellows | Onion
DISEASE: Aster yellows
HOST: Onion (Allium cepa)
PATHOGEN: 'Candidatus Phytoplasma asteris'
PATHOGEN SYNONYM: Phytoplasma Aster yellows group
SOURCE: R. Raabe
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 canker
HOST: Cherry
Cherry with necrotic internal tissues and external symptoms of ooze (gummosis) caused by systemic infection.
Bacterial canker | Cherry
DISEASE: Bacterial canker
HOST: Cherry (Prunus avium)
PATHOGEN: Pseudomonas syringae pv. morsprunorum
SOURCE: D. Funk, A. Alvarez
DISEASE: Bacterial canker
HOST: Cherry
Systemic infection of petioles and leaves.
Bacterial canker | Cherry
DISEASE: Bacterial canker
HOST: Cherry (Prunus avium)
PATHOGEN: Pseudomonas syringae pv. morsprunorum
SOURCE: D. Funk, A. Alvarez
DISEASE: Bacterial canker
HOST: Cherry
Blast stage of canker disease affects flowers, buds, and leaves. Necrotic lesions on fruit may cause distortion.
Bacterial canker | Cherry
DISEASE: Bacterial canker
HOST: Cherry (Prunus avium)
PATHOGEN: Pseudomonas syringae pv. syringae
SOURCE: S. Thomson
DISEASE: Bacterial canker
HOST: Cherry
Cherry petioles with dark necrotic lesions. Premature fruit drop is associated with the disease.
Bacterial canker | Cherry
DISEASE: Bacterial canker
HOST: Cherry (Prunus avium)
PATHOGEN: Pseudomonas syringae pv. syringae
SOURCE: S. Thomson
DISEASE: Bacterial canker
HOST: Cherry
Cherry petioles with spots, sunken centers, and water-soaked, brown margins.
Bacterial canker | Cherry
DISEASE: Bacterial canker
HOST: Cherry (Prunus avium)
PATHOGEN: Pseudomonas syringae pv. syringae
SOURCE: S. Thomson
DISEASE: Bacterial canker
HOST: Cherry
Cherry tree with cankers and bacterial ooze.
Bacterial canker | Cherry
DISEASE: Bacterial canker
HOST: Cherry (Prunus avium)
PATHOGEN: Pseudomonas syringae pv. syringae
SOURCE: A. Jones, M. Shurtleff