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 leaf spot (Blight)
HOST: Poinsettia
Blighted leaves and stems.
Bacterial leaf spot (Blight) | Poinsettia
DISEASE: Bacterial leaf spot (Blight)
HOST: Poinsettia (Euphorbia pulcherrima)
PATHOGEN: Curtobacterium flaccumfaciens pv. poinsettiae
SOURCE: APS
DISEASE: Bacterial leaf spot (Blight)
HOST: Poinsettia
Poinsettia with diseased stem. Woody stems may have a yellowed cortex and dark vascular tissues. The stem tip may curve with deformed terminal leaves.
Bacterial leaf spot (Blight) | Poinsettia
DISEASE: Bacterial leaf spot (Blight)
HOST: Poinsettia (Euphorbia pulcherrima)
PATHOGEN: Curtobacterium flaccumfaciens pv. poinsettiae
SOURCE: APS
DISEASE: Bacterial leaf spot (Blight)
HOST: Poinsettia
Leaves with small, dark spots, an early stage of disease.
Bacterial leaf spot (Blight) | Poinsettia
DISEASE: Bacterial leaf spot (Blight)
HOST: Poinsettia (Euphorbia pulcherrima)
PATHOGEN: Curtobacterium flaccumfaciens pv. poinsettiae
SOURCE: A. Alvarez
DISEASE: Bacterial leaf spot
HOST: Poinsettia
Leaves with reddish brown blighted areas and spots. Severely spotted leaves turn yellow and dehisce.
Bacterial leaf spot | Poinsettia
DISEASE: Bacterial leaf spot
HOST: Poinsettia (Euphorbia pulcherrima)
PATHOGEN: Xanthomonas axonopodis pv. poinsettiicola
PATHOGEN SYNONYM: Xanthomonas campestris pv. poinsettiicola
SOURCE: A. Chase
DISEASE: Bacterial spot
HOST: Plum
Shot-hole phase of disease.
Bacterial spot | Plum
DISEASE: Bacterial spot
HOST: Plum (Prunus domestica)
PATHOGEN: Xanthomonas arboricola pv. pruni
PATHOGEN SYNONYM: Xanthomonas campestris pv. pruni
SOURCE: T. Burr
DISEASE: Bacterial spot
HOST: Plum
Dark, sunken area on blossom end of fruit.
Bacterial spot | Plum
DISEASE: Bacterial spot
HOST: Plum (Prunus domestica)
PATHOGEN: Xanthomonas arboricola pv. pruni
PATHOGEN SYNONYM: Xanthomonas campestris pv. pruni
SOURCE: S. Thomson
DISEASE: Bacterial spot
HOST: Plum
Dark brown necrotic lesions along main leaf vein. Lesions may drop off, leaving shot-hole effect.
Bacterial spot | Plum
DISEASE: Bacterial spot
HOST: Plum (Prunus domestica)
PATHOGEN: Xanthomonas arboricola pv. pruni
PATHOGEN SYNONYM: Xanthomonas campestris pv. pruni
SOURCE: S. Thomson
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