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: Brittle root
HOST: Horseradish
Dying, stunted, yellow to brown horseradish plants.
Brittle root | Horseradish
DISEASE: Brittle root
HOST: Horseradish (Armoracia rusticana)
PATHOGEN: Spiroplasma citri
SOURCE: C. Eastman, M. Davis
DISEASE: Brittle root
HOST: Horseradish
Close-up of stunted, yellow horseradish plants.
Brittle root | Horseradish
DISEASE: Brittle root
HOST: Horseradish (Armoracia rusticana)
PATHOGEN: Spiroplasma citri
SOURCE: D. Sherrod
DISEASE: Brittle root
HOST: Horseradish
Horseradish with discolored internal tissues. Healthy root segment (top right).
Brittle root | Horseradish
DISEASE: Brittle root
HOST: Horseradish (Armoracia rusticana)
PATHOGEN: Spiroplasma citri
SOURCE: J. Fletcher, M. Davis