DISEASE: Bacterial blight
HOST: Hazelnut
Diseased young tree with discoloration of the cambium. Dieback of young twigs and branches is characteristic. Other typical symptoms are bud and twig necrosis and small, angular or round, water-soaked leaf spots.

Bacterial blight | Hazelnut
DISEASE: Bacterial blight
HOST: Hazelnut (Corylus americana)
PATHOGEN: Xanthomonas arboricola pv. corylina
SOURCE: J. Pscheidt
DISEASE: Bacterial leaf blight
HOST: Carrot
Blight of flower parts.

Bacterial leaf blight | Carrot
DISEASE: Bacterial leaf blight
HOST: Carrot (Daucus carota)
PATHOGEN: Xanthomonas hortorum pv. carotae
PATHOGEN SYNONYM: Xanthomonas campestris pv. carotae
SOURCE: N. Schaad
DISEASE: Bacterial leaf blight
HOST: Carrot
Leaf lesions begin as water-soaked spots that progress to small, yellow, angular spots and later expand to necrotic lesions with yellow halos.

Bacterial leaf blight | Carrot
DISEASE: Bacterial leaf blight
HOST: Carrot (Daucus carota)
PATHOGEN: Xanthomonas hortorum pv. carotae
PATHOGEN SYNONYM: Xanthomonas campestris pv. carotae
SOURCE: N. Schaad
DISEASE: Bacterial leaf blight
HOST: Carrot
Bacterial ooze on flower stalk from systemic invasion of the pathogen.

Bacterial leaf blight | Carrot
DISEASE: Bacterial leaf blight
HOST: Carrot (Daucus carota)
PATHOGEN: Xanthomonas hortorum pv. carotae
PATHOGEN SYNONYM: Xanthomonas campestris pv. carotae
SOURCE: APS
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