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: Corky root
HOST: Lettuce
Corky root causes a reduction in size of lettuce heads and root systems; susceptible cultivar (right) and resistant cultivar (left).

Corky root | Lettuce
DISEASE: Corky root
HOST: Lettuce (Lactuca sativa)
PATHOGEN: Sphingomonas suberifaciens
PATHOGEN SYNONYM: Rhizomonas suberifaciens
SOURCE: E. J. Ryder
DISEASE: Corky root
HOST: Lettuce
Close-up of root with malformed, corky appearance and longitudinal ridges of brown tissues.

Corky root | Lettuce
DISEASE: Corky root
HOST: Lettuce (Lactuca sativa)
PATHOGEN: Sphingomonas suberifaciens
PATHOGEN SYNONYM: Rhizomonas suberifaciens
SOURCE: A. van Bruggen
DISEASE: Corky root
HOST: Lettuce
Initial symptoms of disease are yellow lesions on taproot and main laterals. Greenish brown bands occur around roots. Root pith may become brown and hollow.

Corky root | Lettuce
DISEASE: Corky root
HOST: Lettuce (Lactuca sativa)
PATHOGEN: Sphingomonas suberifaciens
PATHOGEN SYNONYM: Rhizomonas suberifaciens
SOURCE: A. van Bruggen
DISEASE: Corky root
HOST: Lettuce
Differences in corky root symptoms between susceptible cultivar (right) and resistant cultivar (left).

Corky root | Lettuce
DISEASE: Corky root
HOST: Lettuce (Lactuca sativa)
PATHOGEN: Sphingomonas suberifaciens
PATHOGEN SYNONYM: Rhizomonas suberifaciens
SOURCE: E. Ryder
DISEASE: Goss's bacterial wilt and blight
HOST: Corn (Maize)
Wilted, dying plants. Leaves have gray to light yellow stripes and irregular margins that follow leaf veins. Systemically infected plants usually have orange vascular bundles.

Goss's bacterial wilt and blight | Corn (Maize)
DISEASE: Goss's bacterial wilt and blight
HOST: Corn (Maize) (Zea mays)
PATHOGEN: Clavibacter michiganensis subsp. nebraskensis
PATHOGEN SYNONYM: Corynebacterium nebraskense
SOURCE: A. Vidaver
DISEASE: Goss's bacterial wilt and blight
HOST: Corn (Maize)
The disease causes necrotic leaf lesions, which typically have dark flecks (freckles) within the lesions (not seen here).

Goss's bacterial wilt and blight | Corn (Maize)
DISEASE: Goss's bacterial wilt and blight
HOST: Corn (Maize) (Zea mays)
PATHOGEN: Clavibacter michiganensis subsp. nebraskensis
PATHOGEN SYNONYM: Corynebacterium nebraskense
SOURCE: A. Vidaver