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 wilt
HOST: Grass
Wilted and dead patches of diseased creeping bent grass (Toronto grass) on golf green.

Bacterial wilt | Grass
DISEASE: Bacterial wilt
HOST: Grass (Agrostis stolonifera)
PATHOGEN: Xanthomonas translucens pv. poae
SOURCE: D. Roberts
DISEASE: Bacterial wilt
HOST: Grass
Irregular disease patterns on golf green. The cultivars Toronto, Cohansey, and Nimisilia are primary hosts of the disease.

Bacterial wilt | Grass
DISEASE: Bacterial wilt
HOST: Grass (Agrostis stolonifera)
PATHOGEN: Xanthomonas translucens pv. poae
SOURCE: D. Roberts
DISEASE: Brown blotch
HOST: Mushroom
Mushrooms with rotted, brownish discoloration of infected areas.

Brown blotch | Mushroom
DISEASE: Brown blotch
HOST: Mushroom (Agaricus campestris)
PATHOGEN: Pseudomonas tolaasii
SOURCE: J. Young
DISEASE: Drippy gill
HOST: Mushroom
Drippy gill is characterized by small dark spots on gills with drops of bacterial ooze at the centers. Severe infection results in slimy areas and collapse of gills.

Drippy gill | Mushroom
DISEASE: Drippy gill
HOST: Mushroom (Agaricus campestris)
PATHOGEN: Pseudomonas agarici
SOURCE: J. Young
DISEASE: Drippy gill
HOST: Mushroom
Close-up of infected gills with bacterial ooze.

Drippy gill | Mushroom
DISEASE: Drippy gill
HOST: Mushroom (Agaricus campestris)
PATHOGEN: Pseudomonas agarici
SOURCE: J. Young