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 streak
HOST: Oat
Leaf with long, dark red streaks.
Bacterial leaf streak | Oat
DISEASE: Bacterial leaf streak
HOST: Oat (Avena sativa)
PATHOGEN: Xanthomonas translucens pv. cerealis
SOURCE: L. Claflin
DISEASE: Bacterial stripe (Blight)
HOST: Oat
Leaves with irregular necrotic spots and elongated stripes that are light tan in the center. Symptoms begin as water-soaked lesions.
Bacterial stripe (Blight) | Oat
DISEASE: Bacterial stripe (Blight)
HOST: Oat (Avena sativa)
PATHOGEN: Pseudomonas syringae pv. striafaciens
SOURCE: S. Thomson
DISEASE: Halo blight
HOST: Oat
Oat leaves with oval lesions that darken in time and have distinctive yellow halos.
Halo blight | Oat
DISEASE: Halo blight
HOST: Oat (Avena sativa)
PATHOGEN: Pseudomonas syringae pv. coronafaciens
SOURCE: N. Schaad
DISEASE: Halo blight
HOST: Oat
Close-up of young and old lesions surrounded by halos.
Halo blight | Oat
DISEASE: Halo blight
HOST: Oat (Avena sativa)
PATHOGEN: Pseudomonas syringae pv. coronafaciens
SOURCE: N. Schaad
DISEASE: X-disease (Eastern X)
HOST: Chokecherry
Shot-hole stage of X-disease.
X-disease (Eastern X) | Chokecherry
DISEASE: X-disease (Eastern X)
HOST: Chokecherry (Prunus virginiana)
PATHOGEN: 'Candidatus Phytoplasma pruni'
PATHOGEN SYNONYM: Phytoplasma X-disease group
SOURCE: W. Sinclair
DISEASE: X-disease (Eastern X)
HOST: Chokecherry
X-disease causes rosettes and premature loss of leaves.
X-disease (Eastern X) | Chokecherry
DISEASE: X-disease (Eastern X)
HOST: Chokecherry (Prunus virginiana)
PATHOGEN: 'Candidatus Phytoplasma pruni'
PATHOGEN SYNONYM: Phytoplasma X-disease group
SOURCE: W. Sinclair
DISEASE: X-disease (Eastern X)
HOST: Chokecherry
Chokecherry with stunted shoots, red leaves, and rosettes.
X-disease (Eastern X) | Chokecherry
DISEASE: X-disease (Eastern X)
HOST: Chokecherry (Prunus virginiana)
PATHOGEN: 'Candidatus Phytoplasma pruni'
PATHOGEN SYNONYM: Phytoplasma X-disease group
SOURCE: W. Sinclair