DISEASE: Bacterial leaf spot (Bacterial necrosis)
HOST: Cassava
Cassava with yellowish leaves and water-soaked, angular spots. The disease is primarily on foliage, although the pathogen may invade stem buds and young branches.

Bacterial leaf spot (Bacterial necrosis) | Cassava
DISEASE: Bacterial leaf spot (Bacterial necrosis)
HOST: Cassava (Manihot esculenta)
PATHOGEN: Xanthomonas cassavae
PATHOGEN SYNONYM: Xanthomonas campestris pv. cassavae
SOURCE: APS
DISEASE: Bacterial leaf spot (Bacterial necrosis)
HOST: Cassava
Cassava with brownish lesions and blackish edges. Leaves turn yellow with multiple infection sites.

Bacterial leaf spot (Bacterial necrosis) | Cassava
DISEASE: Bacterial leaf spot (Bacterial necrosis)
HOST: Cassava (Manihot esculenta)
PATHOGEN: Xanthomonas cassavae
PATHOGEN SYNONYM: Xanthomonas campestris pv. cassavae
SOURCE: H. Maraite, A. Alvarez
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: Sour skin
HOST: Onion
Symptoms of sour skin are characterized by slimy, pale yellow to light brown decay.

Sour skin | Onion
DISEASE: Sour skin
HOST: Onion (Allium cepa)
PATHOGEN: Burkholderia cepacia
PATHOGEN SYNONYM: Pseudomonas cepacia
SOURCE: Dep. of Agric. & Agri-Food, Government of Canada