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: Aster yellows
HOST: Wheat
Healthy head (left) and diseased head (right). Diseased seedlings may die within 2 to 3 weeks. Infected heads of surviving plants are small and sterile, with distorted awns.
Aster yellows | Wheat
DISEASE: Aster yellows
HOST: Wheat (Triticum aestivum)
PATHOGEN: 'Candidatus Phytoplasma asteris'
PATHOGEN SYNONYM: Phytoplasma Aster yellows group
SOURCE: L. N. Chiykowski
DISEASE: Aster yellows
HOST: Zinnia
Yellowing and shoot proliferation of foliage.
Aster yellows | Zinnia
DISEASE: Aster yellows
HOST: Zinnia (Zinnia violacea)
PATHOGEN: 'Candidatus Phytoplasma asteris'
PATHOGEN SYNONYM: Phytoplasma Aster yellows group
SOURCE: J. Forsberg, M. Shurtleff
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 leaf spot
HOST: Ficus
Leaf exhibiting systemic invasion of veinal tissues.
Bacterial leaf spot | Ficus
DISEASE: Bacterial leaf spot
HOST: Ficus (Ficus lyrata)
PATHOGEN: Pseudomonas cichorii
SOURCE: J. Yuen
DISEASE: Bacterial leaf spot
HOST: Geranium
Disease begins as water-soaked lesions that become brown to black and may coalesce, forming large necrotic areas.
Bacterial leaf spot | Geranium
DISEASE: Bacterial leaf spot
HOST: Geranium (Pelargonium sp.)
PATHOGEN: Pseudomonas cichorii
SOURCE: R. Raabe
DISEASE: Bacterial leaf spot
HOST: Lavender
Lavender leaves with dark necrotic areas.
Bacterial leaf spot | Lavender
DISEASE: Bacterial leaf spot
HOST: Lavender (Lavandula sp.)
PATHOGEN: Pseudomonas cichorii
SOURCE: R. Raabe