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 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: Black chaff (Bacterial leaf streak)
HOST: Wheatgrass
Lesions on leaves first appear as water-soaked, translucent, long, narrow streaks. They later turn brown and necrotic and often coalesce into blighted areas.

Black chaff (Bacterial leaf streak) | Wheatgrass
DISEASE: Black chaff (Bacterial leaf streak)
HOST: Wheatgrass (Elytrigia intermedia)
PATHOGEN: Xanthomonas translucens pv. cerealis
SOURCE: S. Mohan
DISEASE: Black chaff (Bacterial leaf streak)
HOST: Wheatgrass
Close-up of leaf with brown necrotic streaks.

Black chaff (Bacterial leaf streak) | Wheatgrass
DISEASE: Black chaff (Bacterial leaf streak)
HOST: Wheatgrass (Elytrigia intermedia)
PATHOGEN: Xanthomonas translucens pv. cerealis
SOURCE: S. Mohan
DISEASE: Walnut blight
HOST: Walnut
Typical symptoms of infected leaf and young nutlets. Infected young, growing leaves usually become malformed.

Walnut blight | Walnut
DISEASE: Walnut blight
HOST: Walnut (Juglans regia 'Hartley')
PATHOGEN: Xanthomonas arboricola pv. juglandis
SOURCE: M. Schroth
DISEASE: Walnut blight
HOST: Walnut
Tree with severely blighted foliage.

Walnut blight | Walnut
DISEASE: Walnut blight
HOST: Walnut (Juglans regia 'Hartley')
PATHOGEN: Xanthomonas arboricola pv. juglandis
SOURCE: M. Schroth
DISEASE: Walnut blight
HOST: Walnut
Nuts with side blight. Infections also are commonly found at stylar ends.

Walnut blight | Walnut
DISEASE: Walnut blight
HOST: Walnut (Juglans regia 'Hartley')
PATHOGEN: Xanthomonas arboricola pv. juglandis
SOURCE: B. Teviotdale
DISEASE: Walnut blight
HOST: Walnut
Nuts with decayed kernels.

Walnut blight | Walnut
DISEASE: Walnut blight
HOST: Walnut (Juglans regia 'Hartley')
PATHOGEN: Xanthomonas arboricola pv. juglandis
SOURCE: B. Teviotdale