DISEASE: Bacterial blight (Leaf spot)
HOST: Clover
Diseased leaf with elongated, reddish brown lesions, especially numerous on the margins.

Bacterial blight (Leaf spot) | Clover
DISEASE: Bacterial blight (Leaf spot)
HOST: Clover (Trifolium alexandrinum)
PATHOGEN: Pseudomonas syringae pv. syringae
SOURCE: M. Shurtleff
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: European stone fruit yellows
HOST: Almond
The disease causes yellowing and rolling of leaves (right). Leaves become thick and rough in texture. Healthy leaves (left).

European stone fruit yellows | Almond
DISEASE: European stone fruit yellows
HOST: Almond (Prunus dulcis)
PATHOGEN: 'Candidatus Phytoplasma prunorum'
PATHOGEN SYNONYM: Phytoplasma Apple proliferation group
SOURCE: E. Seemueller