DISEASE: Bacterial blight and bacterial leaf streak
HOST: Rice
Xanthomonas oryzae pv. oryzicola (bacterial leaf streak) causes water-soaked streaks with yellow ooze (left side), and X. oryzae pv. oryzae (bacterial blight) causes brown streaks that have turned white (right side).

Bacterial blight and bacterial leaf streak | Rice
DISEASE: Bacterial blight and bacterial leaf streak
HOST: Rice (Oryza sativa)
PATHOGEN: Xanthomonas oryzae pv. oryzicola
PATHOGEN SYNONYM: Xanthomonas campestris pv. oryzae
SOURCE: T. Mew
DISEASE: Bacterial leaf streak
HOST: Rice
Severely diseased leaves with light brown streaks.

Bacterial leaf streak | Rice
DISEASE: Bacterial leaf streak
HOST: Rice (Oryza sativa)
PATHOGEN: Xanthomonas oryzae pv. oryzicola
SOURCE: H. Kaku, M. Goto
DISEASE: Bacterial leaf streak
HOST: Rice
Brownish lesions with tiny droplets of bacterial ooze, resulting from artificial inoculation of the pathogen.

Bacterial leaf streak | Rice
DISEASE: Bacterial leaf streak
HOST: Rice (Oryza sativa)
PATHOGEN: Xanthomonas oryzae pv. oryzicola
SOURCE: H. Kaku, M. Goto
DISEASE: Bacterial leaf streak
HOST: Rice
Copious droplets of bacterial ooze on infected leaf margin (right), typical of advanced stage of disease. Healthy part of leaf (left) has clear guttation fluid.

Bacterial leaf streak | Rice
DISEASE: Bacterial leaf streak
HOST: Rice (Oryza sativa)
PATHOGEN: Xanthomonas oryzae pv. oryzicola
SOURCE: A. Hayward
DISEASE: Chocolate spot
HOST: Corn (Maize)
Leaf with dark brown, elongated spots surrounded by broad, yellow halos.

Chocolate spot | Corn (Maize)
DISEASE: Chocolate spot
HOST: Corn (Maize) (Zea mays)
PATHOGEN: Pseudomonas syringae pv. coronafaciens
SOURCE: D. White
DISEASE: Ear rot
HOST: Corn (Maize)
Rot at apical end of ear.

Ear rot | Corn (Maize)
DISEASE: Ear rot
HOST: Corn (Maize) (Zea mays)
PATHOGEN: Pseudomonas marginalis
SOURCE: L. Fucikovsky
DISEASE: Halo blight
HOST: Oat
Oat leaves with oval lesions that darken in time and have distinctive yellow halos.

Halo blight | Oat
DISEASE: Halo blight
HOST: Oat (Avena sativa)
PATHOGEN: Pseudomonas syringae pv. coronafaciens
SOURCE: N. Schaad
DISEASE: Halo blight
HOST: Oat
Close-up of young and old lesions surrounded by halos.

Halo blight | Oat
DISEASE: Halo blight
HOST: Oat (Avena sativa)
PATHOGEN: Pseudomonas syringae pv. coronafaciens
SOURCE: N. Schaad
DISEASE: Marginal leaf blight
HOST: Lettuce
Marginal leaf blight first appears as slimy wilting of leaf margins. Small, reddish lesions may be seen on leaf blades. Infected tissues turn brown to black in time.

Marginal leaf blight | Lettuce
DISEASE: Marginal leaf blight
HOST: Lettuce (Lactuca sativa)
PATHOGEN: Pseudomonas marginalis
SOURCE: L. Fucikovsky