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 blight
HOST: Lilac
Blighted twig with shriveled leaves and dark brown streaks on stem.

Bacterial blight | Lilac
DISEASE: Bacterial blight
HOST: Lilac (Syringa vulgaris)
PATHOGEN: Pseudomonas syringae pv. syringae
SOURCE: S. Thomson
DISEASE: Bacterial blight
HOST: Lilac
Lilac with blighted twigs.

Bacterial blight | Lilac
DISEASE: Bacterial blight
HOST: Lilac (Syringa vulgaris)
PATHOGEN: Pseudomonas syringae pv. syringae
SOURCE: W. Sinclair
DISEASE: Bacterial blight
HOST: Mulberry
Leaf with numerous small, dark brown lesions with chlorotic halos.

Bacterial blight | Mulberry
DISEASE: Bacterial blight
HOST: Mulberry (Morus alba)
PATHOGEN: Pseudomonas syringae pv. mori
SOURCE: S. Thomson
DISEASE: Bacterial blight
HOST: Mulberry
Foliage with small, dark lesions with large, yellowish halos.

Bacterial blight | Mulberry
DISEASE: Bacterial blight
HOST: Mulberry (Morus sp.)
PATHOGEN: Pseudomonas syringae pv. mori
SOURCE: M. Sato, M. Goto
DISEASE: Bacterial blight
HOST: Mulberry
Blighted foliage with yellowing and curling of leaves.

Bacterial blight | Mulberry
DISEASE: Bacterial blight
HOST: Mulberry (Morus sp.)
PATHOGEN: Pseudomonas syringae pv. mori
SOURCE: M. Sato, M. Goto
DISEASE: Bacterial flower stalk and leaf necrosis
HOST: Onion
Dark, rotted areas of stalk and leaves caused by systemic invasion of the pathogen.

Bacterial flower stalk and leaf necrosis | Onion
DISEASE: Bacterial flower stalk and leaf necrosis
HOST: Onion (Allium cepa)
PATHOGEN: Pseudomonas marginalis pv. marginalis
SOURCE: S. Mohan
DISEASE: Bacterial flower stalk and leaf necrosis
HOST: Onion
Gray-brown rot of onion after inoculation. Disease starts as small, water-soaked lesions that later develop into slimy, gray-brown rot. The disease progresses downward from the stalk and may rot the entire bulb.

Bacterial flower stalk and leaf necrosis | Onion
DISEASE: Bacterial flower stalk and leaf necrosis
HOST: Onion (Allium cepa)
PATHOGEN: Pseudomonas marginalis pv. marginalis
SOURCE: R. Gitaitis