DISEASE: Aster yellows
HOST: Watercress
Diseased watercress (left) and healthy plant (right).

Aster yellows | Watercress
DISEASE: Aster yellows
HOST: Watercress (Nasturtium officinale)
PATHOGEN: 'Candidatus Phytoplasma asteris'
PATHOGEN SYNONYM: Phytoplasma Aster yellows group
SOURCE: W. Borth
DISEASE: Bacterial blight (Brown stem)
HOST: Celery
Lesions are necrotic and circular to angular. Some have yellowish halos. Older lesions become brown and dry.

Bacterial blight (Brown stem) | Celery
DISEASE: Bacterial blight (Brown stem)
HOST: Celery (Apium graveolens)
PATHOGEN: Pseudomonas cichorii
SOURCE: R. Raid
DISEASE: Bacterial blight (Brown stem)
HOST: Celery
Ooze from lesion on celery leaf.

Bacterial blight (Brown stem) | Celery
DISEASE: Bacterial blight (Brown stem)
HOST: Celery (Apium graveolens)
PATHOGEN: Pseudomonas cichorii
SOURCE: R. Raid
DISEASE: Bacterial blight (Brown stem)
HOST: Celery
Characteristic brown discoloration of petioles, which is more evident on inside of petiole close to the crown. Parenchyma tissues are firm and brown.

Bacterial blight (Brown stem) | Celery
DISEASE: Bacterial blight (Brown stem)
HOST: Celery (Apium graveolens)
PATHOGEN: Pseudomonas cichorii
SOURCE: K. Pernezny
DISEASE: Bacterial dieback of nectarine
HOST: Nectarine
Fruit lesions is another symptom of this disease.

Bacterial dieback of nectarine | Nectarine
DISEASE: Bacterial dieback of nectarine
HOST: Nectarine (Prunus persica var. nucipersica 'Redgold')
PATHOGEN: Pseudomonas syringae pv. persicae
SOURCE: J. Young
DISEASE: Bacterial leaf spot
HOST: Celery
Leaves with typical symptoms of rusty brown lesions with greasy appearance.

Bacterial leaf spot | Celery
DISEASE: Bacterial leaf spot
HOST: Celery (Apium graveolens)
PATHOGEN: Pseudomonas syringae pv. apii
SOURCE: R. Gilbertson
DISEASE: Bacterial leaf spot
HOST: Celery
Celery leaves with rusty brown lesions and some yellowing at leaf tips.

Bacterial leaf spot | Celery
DISEASE: Bacterial leaf spot
HOST: Celery (Apium graveolens)
PATHOGEN: Pseudomonas syringae pv. apii
SOURCE: S. Koike
DISEASE: Bacterial spot
HOST: Nectarine
Nectarine with necrotic spots on leaves and dark necrotic spots on fruit.

Bacterial spot | Nectarine
DISEASE: Bacterial spot
HOST: Nectarine (Prunus persica var. nucipersica 'Redgold')
PATHOGEN: Xanthomonas arboricola pv. pruni
PATHOGEN SYNONYM: Xanthomonas campestris pv. pruni
SOURCE: J. Young