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 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 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: Orchid
Infected leaf of Phalaenopsis orchid with light brown necrotic area.
Bacterial leaf spot | Orchid
DISEASE: Bacterial leaf spot
HOST: Orchid (Phalaenopsis sp.)
PATHOGEN: Pectobacterium cypripedii
PATHOGEN SYNONYM: Erwinia cypripedii
SOURCE: R. McMillan
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: 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