DISEASE: Bacterial blight (Angular leaf spot)
HOST: Cotton
Leaf with advanced stage of blight.

Bacterial blight (Angular leaf spot) | Cotton
DISEASE: Bacterial blight (Angular leaf spot)
HOST: Cotton (Gossypium barbadense)
PATHOGEN: Xanthomonas citri subsp. malvacearum
PATHOGEN SYNONYM: Xanthomonas campestris pv. malvacearum
SOURCE: M. Shurtleff
DISEASE: Bacterial blight (Angular leaf spot)
HOST: Cotton
Highly susceptible (left) and resistant (right) cotton cultivars. The black arm stage of the disease is the most serious and occurs when bacteria invade petioles and then stems.

Bacterial blight (Angular leaf spot) | Cotton
DISEASE: Bacterial blight (Angular leaf spot)
HOST: Cotton (Gossypium barbadense)
PATHOGEN: Xanthomonas citri subsp. malvacearum
PATHOGEN SYNONYM: Xanthomonas campestris pv. malvacearum
SOURCE: APS
DISEASE: Bacterial blight (Angular leaf spot)
HOST: Cotton
Characteristic early symptoms are water-soaked leaf spots and water-soaking along veins.

Bacterial blight (Angular leaf spot) | Cotton
DISEASE: Bacterial blight (Angular leaf spot)
HOST: Cotton (Gossypium barbadense)
PATHOGEN: Xanthomonas citri subsp. malvacearum
PATHOGEN SYNONYM: Xanthomonas campestris pv. malvacearum
SOURCE: A. Hayward
DISEASE: Bacterial blight (Angular leaf spot)
HOST: Cotton
Leaf with dark, angular leaf spots. Systemic invasion causes blackening of midribs.

Bacterial blight (Angular leaf spot) | Cotton
DISEASE: Bacterial blight (Angular leaf spot)
HOST: Cotton (Gossypium barbadense)
PATHOGEN: Xanthomonas citri subsp. malvacearum
PATHOGEN SYNONYM: Xanthomonas campestris pv. malvacearum
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
DISEASE: Greasy center
HOST: Poinsettia
Stem with dark cankers and copious ooze. Necrotic areas are greasy in appearance and eventually turn light tan to brown with a papery texture as the cuticle becomes detached.

Greasy center | Poinsettia
DISEASE: Greasy center
HOST: Poinsettia (Euphorbia pulcherrima)
PATHOGEN: Pseudomonas viridiflava
SOURCE: R. Raabe