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 wilt
HOST: Grass
Initial symptom is a lime-green, yellow, or blue-green appearance of the grass. The next symptom is small, reddish brown spots on leaf blades.
Bacterial wilt | Grass
DISEASE: Bacterial wilt
HOST: Grass (Poa annua)
PATHOGEN: Xanthomonas translucens pv. poae
SOURCE: P. H. Dernoeden
DISEASE: Bacterial wilt
HOST: Grass
Infected turf grass with patches of yellowing, wilted, and dead grass.
Bacterial wilt | Grass
DISEASE: Bacterial wilt
HOST: Grass (Poa annua)
PATHOGEN: Xanthomonas translucens pv. poae
SOURCE: APS
DISEASE: Bacterial wilt
HOST: Grass
Late stage of disease development. Dead grass has a light brown or bleached tan appearance.
Bacterial wilt | Grass
DISEASE: Bacterial wilt
HOST: Grass (Poa annua)
PATHOGEN: Xanthomonas translucens pv. poae
SOURCE: P. H. Dernoeden