DISEASE: Aster yellows
HOST: Squash
Diagnostic characteristics for the disease are yellowing of young leaves, proliferation of secondary shoots, and rigid erect habit. Leaves are misshapen and smaller than normal and have stiff, thick laminae.
Aster yellows | Squash
DISEASE: Aster yellows
HOST: Squash (Cucurbita sp.)
PATHOGEN: 'Candidatus Phytoplasma asteris'
PATHOGEN SYNONYM: Phytoplasma Aster yellows group
SOURCE: S. Miller
DISEASE: Bacterial fasciation (Leafy gall)
HOST: Dahlia
Dalhlia tubers with proliferation and leaf development.
Bacterial fasciation (Leafy gall) | Dahlia
DISEASE: Bacterial fasciation (Leafy gall)
HOST: Dahlia (Dahlia sp.)
PATHOGEN: Rhodococcus fascians
SOURCE: M. Shurtleff
DISEASE: Bacterial fasciation (Leafy gall)
HOST: Dahlia
Bacterial fasciation of dahlia tubers.
Bacterial fasciation (Leafy gall) | Dahlia
DISEASE: Bacterial fasciation (Leafy gall)
HOST: Dahlia (Dahlia sp.)
PATHOGEN: Rhodococcus fascians
SOURCE: H. van Hoof, M. Geesteranus
DISEASE: Bacterial fruit blotch
HOST: Cantaloupe
Early stage of disease with discolored blotches on the surface.
Bacterial fruit blotch | Cantaloupe
DISEASE: Bacterial fruit blotch
HOST: Cantaloupe (Cucumis melo var. cantalupensis)
PATHOGEN: Acidovorax citrulli
PATHOGEN SYNONYM: Acidovorax avenae subsp. citrulli
SOURCE: D. B. Langston
DISEASE: Bacterial fruit blotch
HOST: Cantaloupe
View of disease path from rind to internal rotting of melon.
Bacterial fruit blotch | Cantaloupe
DISEASE: Bacterial fruit blotch
HOST: Cantaloupe (Cucumis melo var. cantalupensis)
PATHOGEN: Acidovorax citrulli
PATHOGEN SYNONYM: Acidovorax avenae subsp. citrulli
SOURCE: R. Gitaitis
DISEASE: Bacterial fruit blotch
HOST: Cantaloupe
Leaf spot stage. Lesions start small and may coalesce, forming large, brown necrotic areas.
Bacterial fruit blotch | Cantaloupe
DISEASE: Bacterial fruit blotch
HOST: Cantaloupe (Cucumis melo var. cantalupensis)
PATHOGEN: Acidovorax citrulli
PATHOGEN SYNONYM: Acidovorax avenae subsp. citrulli
SOURCE: D. B. Langston
DISEASE: Bacterial rot
HOST: Dahlia
Longitudinal section of dahlia with discolored, rotted tissues.
Bacterial rot | Dahlia
DISEASE: Bacterial rot
HOST: Dahlia (Dahlia sp.)
PATHOGEN: Dickeya sp.
PATHOGEN SYNONYM: Erwinia chrysanthemi
SOURCE: J. Young
DISEASE: Bacterial wilt
HOST: Cantaloupe
Cantaloupe field with severe destruction from bacterial wilt (left), less on right.
Bacterial wilt | Cantaloupe
DISEASE: Bacterial wilt
HOST: Cantaloupe (Cucumis melo var. cantalupensis)
PATHOGEN: Erwinia tracheiphila
SOURCE: L. Claflin
DISEASE: Crown gall
HOST: Dahlia
Crown gall of dahlia tubers. Note brownish, rough-surfaced galls, one of which shows rot. Galls often are infected by microorganisms that cause rot.
Crown gall | Dahlia
DISEASE: Crown gall
HOST: Dahlia (Dahlia sp.)
PATHOGEN: Agrobacterium tumefaciens
PATHOGEN SYNONYM: Rhizobium sp.
SOURCE: M. Shurtleff