DISEASE: Brittle root
HOST: Horseradish
Dying, stunted, yellow to brown horseradish plants.

Brittle root | Horseradish
DISEASE: Brittle root
HOST: Horseradish (Armoracia rusticana)
PATHOGEN: Spiroplasma citri
SOURCE: C. Eastman, M. Davis
DISEASE: Brittle root
HOST: Horseradish
Close-up of stunted, yellow horseradish plants.

Brittle root | Horseradish
DISEASE: Brittle root
HOST: Horseradish (Armoracia rusticana)
PATHOGEN: Spiroplasma citri
SOURCE: D. Sherrod
DISEASE: Brittle root
HOST: Horseradish
Horseradish with discolored internal tissues. Healthy root segment (top right).

Brittle root | Horseradish
DISEASE: Brittle root
HOST: Horseradish (Armoracia rusticana)
PATHOGEN: Spiroplasma citri
SOURCE: J. Fletcher, M. Davis
DISEASE: Pseudomonas leaf spot
HOST: Primrose
Leaf with brownish red spots and reddening of adjacent areas. Disease begins as small, water-soaked lesions that later coalesce into large necrotic spots.

Pseudomonas leaf spot | Primrose
DISEASE: Pseudomonas leaf spot
HOST: Primrose (Primula sp.)
PATHOGEN: Pseudomonas syringae pv. primulae
SOURCE: APS
DISEASE: X-disease (Eastern X)
HOST: Chokecherry
Shot-hole stage of X-disease.

X-disease (Eastern X) | Chokecherry
DISEASE: X-disease (Eastern X)
HOST: Chokecherry (Prunus virginiana)
PATHOGEN: 'Candidatus Phytoplasma pruni'
PATHOGEN SYNONYM: Phytoplasma X-disease group
SOURCE: W. Sinclair
DISEASE: X-disease (Eastern X)
HOST: Chokecherry
X-disease causes rosettes and premature loss of leaves.

X-disease (Eastern X) | Chokecherry
DISEASE: X-disease (Eastern X)
HOST: Chokecherry (Prunus virginiana)
PATHOGEN: 'Candidatus Phytoplasma pruni'
PATHOGEN SYNONYM: Phytoplasma X-disease group
SOURCE: W. Sinclair
DISEASE: X-disease (Eastern X)
HOST: Chokecherry
Chokecherry with stunted shoots, red leaves, and rosettes.

X-disease (Eastern X) | Chokecherry
DISEASE: X-disease (Eastern X)
HOST: Chokecherry (Prunus virginiana)
PATHOGEN: 'Candidatus Phytoplasma pruni'
PATHOGEN SYNONYM: Phytoplasma X-disease group
SOURCE: W. Sinclair
DISEASE: X-disease (Eastern X)
HOST: Chokecherry
Chokecherry with red leaves, rosettes, and bud loss.

X-disease (Eastern X) | Chokecherry
DISEASE: X-disease (Eastern X)
HOST: Chokecherry (Prunus virginiana)
PATHOGEN: 'Candidatus Phytoplasma pruni'
PATHOGEN SYNONYM: Phytoplasma X-disease group
SOURCE: W. Sinclair