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 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: 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
DISEASE: Crown gall
HOST: Grape
Gall on base of 'Zinfandel' grape in California, where aerial galls are less common because of dry, hot weather.
Crown gall | Grape
DISEASE: Crown gall
HOST: Grape (Vitis vinifera 'Zinfandel')
PATHOGEN: Agrobacterium vitis
PATHOGEN SYNONYM: Rhizobium vitus
SOURCE: M. Schroth