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: Purple stain
HOST: Papaya
Purple pigmentation of internal tissues near peduncle end of fruits. Pigmentation and yellow translucence of papaya flesh are more evident of fruit on right.

Purple stain | Papaya
DISEASE: Purple stain
HOST: Papaya (Carica papaya)
PATHOGEN: Pantoea agglomerans
PATHOGEN SYNONYM: Erwinia herbicola
SOURCE: M. Nelson
DISEASE: Purple stain
HOST: Papaya
Purple pigmentation of internal tissues.

Purple stain | Papaya
DISEASE: Purple stain
HOST: Papaya (Carica papaya)
PATHOGEN: Pantoea agglomerans
PATHOGEN SYNONYM: Erwinia herbicola
SOURCE: M. Nelson
DISEASE: Purple stain
HOST: Papaya
Another view of purple discoloration at peduncle end. Bacteria are found in vascular tissues and latex ducts.

Purple stain | Papaya
DISEASE: Purple stain
HOST: Papaya (Carica papaya)
PATHOGEN: Pantoea agglomerans
PATHOGEN SYNONYM: Erwinia herbicola
SOURCE: K. Nishijima
DISEASE: Purple stain
HOST: Papaya
Cross section of fruit exhibiting purplish discoloration in latex ducts.

Purple stain | Papaya
DISEASE: Purple stain
HOST: Papaya (Carica papaya)
PATHOGEN: Pantoea agglomerans
PATHOGEN SYNONYM: Erwinia herbicola
SOURCE: M. Nelson, A. Alvarez
DISEASE: Sugarcane dwarf (White leaf)
HOST: Sugarcane
Unknown phytoplasma causes sugarcane leaves to become white.

Sugarcane dwarf (White leaf) | Sugarcane
DISEASE: Sugarcane dwarf (White leaf)
HOST: Sugarcane (Saccharum officinarum)
PATHOGEN: 'Candidatus Phytoplasma' sp.
PATHOGEN SYNONYM: Phytoplasma (undefined)
SOURCE: A. Alvarez