DISEASE: Australian citrus dieback
HOST: Citrus (Grapefruit)
Leaves with mottled chlorosis.

Australian citrus dieback | Citrus (Grapefruit)
DISEASE: Australian citrus dieback
HOST: Citrus (Grapefruit) (Citrus paradisi)
PATHOGEN: 'Candidatus Phytoplasma' sp.
PATHOGEN SYNONYM: Phytoplasma (undefined)
SOURCE: P. Broadbent
DISEASE: Australian citrus dieback
HOST: Citrus (Grapefruit)
Late stage of disease. Note yellowing of leaf veins and entire leaves.

Australian citrus dieback | Citrus (Grapefruit)
DISEASE: Australian citrus dieback
HOST: Citrus (Grapefruit) (Citrus paradisi)
PATHOGEN: 'Candidatus Phytoplasma' sp.
PATHOGEN SYNONYM: Phytoplasma (undefined)
SOURCE: P. Broadbent
DISEASE: Bacterial blight
HOST: Grass
Timothy grass with light-colored lesions caused by unidentified Xanthomonas sp.

Bacterial blight | Grass
DISEASE: Bacterial blight
HOST: Grass (Phleum pratense)
PATHOGEN: Xanthomonas sp.
SOURCE: M. Shurtleff
DISEASE: Bacterial leaf spot (Head rot)
HOST: Lettuce
Leaf with black, greasy spots that tend to be vein delimited. Lesions begin as small, angular, water-soaked lesions that coalesce, resulting in large necrotic areas.

Bacterial leaf spot (Head rot) | Lettuce
DISEASE: Bacterial leaf spot (Head rot)
HOST: Lettuce (Lactuca sativa)
PATHOGEN: Xanthomonas axonopodis pv. vitians
PATHOGEN SYNONYM: Xanthomonas campestris pv. vitians
SOURCE: A. Alvarez
DISEASE: Citrus canker
HOST: Citrus (Grapefruit)
Grapefruit with corky, raised lesions.

Citrus canker | Citrus (Grapefruit)
DISEASE: Citrus canker
HOST: Citrus (Grapefruit) (Citrus paradisi)
PATHOGEN: Xanthomonas citri subsp. citri
PATHOGEN SYNONYM: Xanthomonas citri
SOURCE: T. Gottwald
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