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: Aster yellows
HOST: Zinnia
Yellowing and shoot proliferation of foliage.

Aster yellows | Zinnia
DISEASE: Aster yellows
HOST: Zinnia (Zinnia violacea)
PATHOGEN: 'Candidatus Phytoplasma asteris'
PATHOGEN SYNONYM: Phytoplasma Aster yellows group
SOURCE: J. Forsberg, M. Shurtleff
DISEASE: Bacterial leaf spot
HOST: Zinnia
Leaf with small, brown spots.

Bacterial leaf spot | Zinnia
DISEASE: Bacterial leaf spot
HOST: Zinnia (Zinnia violacea)
PATHOGEN: Xanthomonas campestris pv. zinniae
SOURCE: M. Goto
DISEASE: Bacterial leaf spot
HOST: Zinnia
Leaf with blackish, necrotic, angular spots.

Bacterial leaf spot | Zinnia
DISEASE: Bacterial leaf spot
HOST: Zinnia (Zinnia violacea)
PATHOGEN: Xanthomonas campestris pv. zinniae
SOURCE: M. Daughtrey
DISEASE: Bacterial spot
HOST: Plum
Infected twig with small cankers.

Bacterial spot | Plum
DISEASE: Bacterial spot
HOST: Plum (Prunus salicina 'Friar')
PATHOGEN: Xanthomonas arboricola pv. pruni
PATHOGEN SYNONYM: Xanthomonas campestris pv. pruni
SOURCE: J. Young
DISEASE: Bacterial spot
HOST: Plum
Close-up of coalescing fruit spots.

Bacterial spot | Plum
DISEASE: Bacterial spot
HOST: Plum (Prunus salicina 'Friar')
PATHOGEN: Xanthomonas arboricola pv. pruni
PATHOGEN SYNONYM: Xanthomonas campestris pv. pruni
SOURCE: S. Mohan
DISEASE: Bacterial spot
HOST: Plum
Close-up of angular leaf spots.

Bacterial spot | Plum
DISEASE: Bacterial spot
HOST: Plum (Prunus salicina 'Friar')
PATHOGEN: Xanthomonas arboricola pv. pruni
PATHOGEN SYNONYM: Xanthomonas campestris pv. pruni
SOURCE: S. Mohan
DISEASE: Bacterial spot
HOST: Plum
Leaf with small, brownish, angular spots. There are no signs of chlorosis.

Bacterial spot | Plum
DISEASE: Bacterial spot
HOST: Plum (Prunus salicina 'Friar')
PATHOGEN: Xanthomonas arboricola pv. pruni
PATHOGEN SYNONYM: Xanthomonas campestris pv. pruni
SOURCE: S. Mohan