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 blight
HOST: Poppy
The disease begins with water-soaked lesions that turn brown to black. They may be surrounded by a translucent ring. Buds, leaves, flowers, and pods are affected.

Bacterial blight | Poppy
DISEASE: Bacterial blight
HOST: Poppy (Eschscholzia californica)
PATHOGEN: Xanthomonas campestris pv. papavericola
SOURCE: M. Daughtrey
DISEASE: Bacterial canker and blast
HOST: Apricot
Apricot with typical reddish brown-discolored tissues beneath the bark and gumming around infected areas.

Bacterial canker and blast | Apricot
DISEASE: Bacterial canker and blast
HOST: Apricot (Prunus armeniaca)
PATHOGEN: Pseudomonas syringae pv. syringae
SOURCE: S. Sampson, M. Shurtleff