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 brown rot
HOST: Orchid
Phalaenopsis orchid with yellowish brown spot on leaf (left), an early stage of disease.
Bacterial brown rot | Orchid
DISEASE: Bacterial brown rot
HOST: Orchid (Phalaenopsis sp.)
PATHOGEN: Acidovorax cattleyae
PATHOGEN SYNONYM: Acidovorax avenae subsp. cattleyae
SOURCE: R. McMillan
DISEASE: Bacterial brown rot
HOST: Orchid
Leaves of Phalaenopsis orchid with advanced stage of decay.
Bacterial brown rot | Orchid
DISEASE: Bacterial brown rot
HOST: Orchid (Phalaenopsis sp.)
PATHOGEN: Acidovorax cattleyae
PATHOGEN SYNONYM: Acidovorax avenae subsp. cattleyae
SOURCE: R. McMillan
DISEASE: Bacterial bud and petal blight
HOST: Orchid
Miltonia orchid with brownish necrotic areas around edges of flower petals.
Bacterial bud and petal blight | Orchid
DISEASE: Bacterial bud and petal blight
HOST: Orchid (Miltonia sp.)
PATHOGEN: Acidovorax cattleyae
SOURCE: R. Raabe
DISEASE: Bacterial bud and petal blight
HOST: Orchid
Miltonia orchid with diseased water-soaked flower buds.
Bacterial bud and petal blight | Orchid
DISEASE: Bacterial bud and petal blight
HOST: Orchid (Miltonia sp.)
PATHOGEN: Acidovorax cattleyae
SOURCE: R. Raabe
DISEASE: Bacterial leaf spot
HOST: Orchid
Diseased leaf of Phalaenopsis orchid with large, dark necrotic area.
Bacterial leaf spot | Orchid
DISEASE: Bacterial leaf spot
HOST: Orchid (Phalaenopsis sp.)
PATHOGEN: Acidovorax cattleyae
PATHOGEN SYNONYM: Acidovorax avenae subsp. cattleyae
SOURCE: R. Raabe
DISEASE: Chocolate spot
HOST: Corn (Maize)
Leaf with dark brown, elongated spots surrounded by broad, yellow halos.
Chocolate spot | Corn (Maize)
DISEASE: Chocolate spot
HOST: Corn (Maize) (Zea mays)
PATHOGEN: Pseudomonas syringae pv. coronafaciens
SOURCE: D. White
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