DISEASE: Bacterial leaf spot
HOST: Citrus (sp. unknown)
Leaf with flat, spreading lesions.

Bacterial leaf spot | Citrus (sp. unknown)
DISEASE: Bacterial leaf spot
HOST: Citrus (sp. unknown) (Citrus sp.)
PATHOGEN: Xanthomonas alfalfae subsp. citrumelonis
PATHOGEN SYNONYM: Xanthomonas alfalfae subsp. citrumelo
SOURCE: J. H. Graham
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: Rugose leaf curl
HOST: Clover
Two rugose, distorted white clover leaves and a healthy leaf. Rugose leaf curl is caused by an unidentified phloem-infecting bacterium.

Rugose leaf curl | Clover
DISEASE: Rugose leaf curl
HOST: Clover (Trifolium repens)
PATHOGEN: Phloem-infecting bacterium
SOURCE: D. Teakle