DISEASE: Bacterial mushy canker
HOST: Papaya
This disease (Micronesia) differs from bacterial decline by causing blackish, water-soaked, mushy cankers near or in leaf axils or on young stems.

Bacterial mushy canker | Papaya
DISEASE: Bacterial mushy canker
HOST: Papaya (Carica papaya)
PATHOGEN: Erwinia sp.
SOURCE: E. Trujillo
DISEASE: Black chaff (Bacterial leaf streak)
HOST: Barley
Black chaff is characterized by water-soaked and darkened glumes on barley heads and streaks and stripes on leaves.

Black chaff (Bacterial leaf streak) | Barley
DISEASE: Black chaff (Bacterial leaf streak)
HOST: Barley (Hordeum vulgare)
PATHOGEN: Xanthomonas translucens pv. undulosa
SOURCE: S. Thomson
DISEASE: Black chaff (Bacterial leaf streak)
HOST: Barley
Leaf with linear, water-soaked lesions that turn necrotic and brown. Flakes of dry bacterial exudate are apparent on the lesions. The pathogen also causes black glume of barley.

Black chaff (Bacterial leaf streak) | Barley
DISEASE: Black chaff (Bacterial leaf streak)
HOST: Barley (Hordeum vulgare)
PATHOGEN: Xanthomonas translucens pv. undulosa
SOURCE: S. Thomson
DISEASE: Black chaff (Bacterial leaf streak)
HOST: Wheat
Water-soaked stage of leaf streak.

Black chaff (Bacterial leaf streak) | Wheat
DISEASE: Black chaff (Bacterial leaf streak)
HOST: Wheat (Triticum aestivum)
PATHOGEN: Xanthomonas translucens pv. undulosa
SOURCE: S. Thomson
DISEASE: Black chaff (Bacterial leaf streak)
HOST: Wheat
Interveinal brown streaks and blotches on wheat leaves, a late stage of disease. Symptoms may be confused with other diseases.

Black chaff (Bacterial leaf streak) | Wheat
DISEASE: Black chaff (Bacterial leaf streak)
HOST: Wheat (Triticum aestivum)
PATHOGEN: Xanthomonas translucens pv. undulosa
SOURCE: R. Kilpatrick
DISEASE: Black chaff (Bacterial leaf streak)
HOST: Wheat
Brownish black streaks and blotches on glumes.

Black chaff (Bacterial leaf streak) | Wheat
DISEASE: Black chaff (Bacterial leaf streak)
HOST: Wheat (Triticum aestivum)
PATHOGEN: Xanthomonas translucens pv. undulosa
SOURCE: M. Boosalis
DISEASE: Black chaff (Bacterial leaf streak)
HOST: Wheat
Leaves with blighted leaf tips, and blades with brownish red streaks.

Black chaff (Bacterial leaf streak) | Wheat
DISEASE: Black chaff (Bacterial leaf streak)
HOST: Wheat (Triticum aestivum)
PATHOGEN: Xanthomonas translucens pv. undulosa
SOURCE: L. Claflin
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