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: Blood disease
HOST: Banana
Yellow leaves of dying plant.

Blood disease | Banana
DISEASE: Blood disease
HOST: Banana (Musa sp.)
PATHOGEN: Ralstonia solanacearum species complex
PATHOGEN SYNONYM: Ralstonia solanacearum (Phylotype IV)
SOURCE: I. Buddenhagen
DISEASE: Blood disease
HOST: Banana
Cross sections of diseased fruit with reddish discoloration and bacterial ooze.

Blood disease | Banana
DISEASE: Blood disease
HOST: Banana (Musa sp.)
PATHOGEN: Ralstonia solanacearum species complex
PATHOGEN SYNONYM: Ralstonia solanacearum (Phylotype IV)
SOURCE: I. Buddenhagen
DISEASE: Blood disease
HOST: Banana
Longitudinal sections (right) exposing reddish brown discoloration of infected fruit.

Blood disease | Banana
DISEASE: Blood disease
HOST: Banana (Musa sp.)
PATHOGEN: Ralstonia solanacearum species complex
PATHOGEN SYNONYM: Ralstonia solanacearum (Phylotype IV)
SOURCE: I. Buddenhagen
DISEASE: Blood disease
HOST: Banana
Diseased plant with wilt and yellowing of leaves. The disease occurs in Indonesia and is characterized by bright red discoloration of vascular tissues. It is caused by strains in the Ralstonia solanacearum species complex.

Blood disease | Banana
DISEASE: Blood disease
HOST: Banana (Musa sp.)
PATHOGEN: Ralstonia solanacearum species complex
PATHOGEN SYNONYM: Ralstonia solanacearum (Phylotype IV)
SOURCE: I. Buddenhagen
DISEASE: Xanthomonas leaf blight
HOST: Onion
This was the first photo of onion leaf blight, which was considered a controversial finding for 10 years until an outbreak occurred in the West Indies.

Xanthomonas leaf blight | Onion
DISEASE: Xanthomonas leaf blight
HOST: Onion (Allium cepa)
PATHOGEN: Xanthomonas axonopodis pv. allii
PATHOGEN SYNONYM: Xanthomonas campestris pv. allii
SOURCE: A. Alvarez