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 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
DISEASE: Bacterial spot
HOST: Plum
Fruit with dark, coalescing lesions.

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: 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
DISEASE: Fire blight
HOST: Plum
Shoot with stem infection.

Fire blight | Plum
DISEASE: Fire blight
HOST: Plum (Prunus salicina 'Friar')
PATHOGEN: Erwinia amylovora
SOURCE: S. Mohan