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: Viola (Horned violet)
The disease causes distortion and overgrowth of axillary buds.

Bacterial fasciation (Leafy gall) | Viola (Horned violet)
DISEASE: Bacterial fasciation (Leafy gall)
HOST: Viola (Horned violet) (Viola cornuta)
PATHOGEN: Rhodococcus fascians
SOURCE: M. Putnam
DISEASE: Citrus greening (Huanglongbing)
HOST: Citrus (Mandarin orange)
The bacterium invades the tree slowly, leading to yellowing of the entire canopy. Pale yellow, blotchy mottled leaves are reduced in size.

Citrus greening (Huanglongbing) | Citrus (Mandarin orange)
DISEASE: Citrus greening (Huanglongbing)
HOST: Citrus (Mandarin orange) (Citrus reticulata)
PATHOGEN: 'Candidatus Liberibacter asiaticus'
PATHOGEN SYNONYM: Candidatus Liberobacter asiaticus
SOURCE: S. M. Garnsey