DISEASE: Aster yellows
HOST: Aster
Foliar symptoms of chlorosis, malformation of leaves, and phyllody.
Aster yellows | Aster
DISEASE: Aster yellows
HOST: Aster (Aster sp.)
PATHOGEN: 'Candidatus Phytoplasma asteris'
PATHOGEN SYNONYM: Phytoplasma Aster yellows group
SOURCE: R. McCoy, M. Davis
DISEASE: Aster yellows
HOST: Aster
Flowers with phyllody (left and center). Healthy flower (right).
Aster yellows | Aster
DISEASE: Aster yellows
HOST: Aster (Aster sp.)
PATHOGEN: 'Candidatus Phytoplasma asteris'
PATHOGEN SYNONYM: Phytoplasma Aster yellows group
SOURCE: R. McCoy, M. Davis
DISEASE: Aster yellows
HOST: Aster
Macrosteles sp., a leafhopper vector of aster yellows phytoplasma.
Aster yellows | Aster
DISEASE: Aster yellows
HOST: Aster (Aster sp.)
PATHOGEN: 'Candidatus Phytoplasma asteris'
PATHOGEN SYNONYM: Phytoplasma Aster yellows group
SOURCE: J. Clark, A. Purcell, M. Davis
DISEASE: Bacterial blight
HOST: Hazelnut
Diseased young tree with discoloration of the cambium. Dieback of young twigs and branches is characteristic. Other typical symptoms are bud and twig necrosis and small, angular or round, water-soaked leaf spots.
Bacterial blight | Hazelnut
DISEASE: Bacterial blight
HOST: Hazelnut (Corylus americana)
PATHOGEN: Xanthomonas arboricola pv. corylina
SOURCE: J. Pscheidt
DISEASE: Bacterial canker
HOST: Hazelnut
Primary symptoms are failure of buds to break and withering and death of new foliage in spring. Dead leaves remain attached to limbs after normal leaf fall.
Bacterial canker | Hazelnut
DISEASE: Bacterial canker
HOST: Hazelnut (Corylus americana)
PATHOGEN: Pseudomonas syringae pv. avellanae
PATHOGEN SYNONYM: Pseudomonas avellanae
SOURCE: P. Psalidas
DISEASE: Bacterial leaf blight
HOST: Sorghum
The disease begins with interveinal water-soaked streaks that broaden into irregularly shaped areas with necrotic centers and red margins.
Bacterial leaf blight | Sorghum
DISEASE: Bacterial leaf blight
HOST: Sorghum (Sorghum bicolor)
PATHOGEN: Acidovorax avenae
PATHOGEN SYNONYM: Acidovorax avenae subsp. avenae
SOURCE: APS
DISEASE: Bacterial leaf spot
HOST: Sorghum
Leaf with red and necrotic streaks along veins.
Bacterial leaf spot | Sorghum
DISEASE: Bacterial leaf spot
HOST: Sorghum (Sorghum bicolor)
PATHOGEN: Pseudomonas syringae pv. syringae
SOURCE: L. Claflin
DISEASE: Bacterial leaf spot
HOST: Sorghum
Clustering of small purplish lesions in localized region of leaf.
Bacterial leaf spot | Sorghum
DISEASE: Bacterial leaf spot
HOST: Sorghum (Sorghum bicolor)
PATHOGEN: Pseudomonas syringae pv. syringae
SOURCE: L. Claflin
DISEASE: Bacterial leaf streak
HOST: Sorghum
Symptoms typically begin as water-soaked streaks expanding into irregular-shaped, reddish brown streaks. Symptoms are similar to bacterial leaf stripe.
Bacterial leaf streak | Sorghum
DISEASE: Bacterial leaf streak
HOST: Sorghum (Sorghum bicolor)
PATHOGEN: Xanthomonas vasicola pv. holcicola
SOURCE: J. Young