DISEASE: Bacterial leaf spot (Head rot)
HOST: Lettuce
Leaf with black, greasy spots that tend to be vein delimited. Lesions begin as small, angular, water-soaked lesions that coalesce, resulting in large necrotic areas.

Bacterial leaf spot (Head rot) | Lettuce
DISEASE: Bacterial leaf spot (Head rot)
HOST: Lettuce (Lactuca sativa)
PATHOGEN: Xanthomonas axonopodis pv. vitians
PATHOGEN SYNONYM: Xanthomonas campestris pv. vitians
SOURCE: A. Alvarez
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: 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: Leaf scald
HOST: Sugarcane
Leaf symptoms of chlorosis and white, "pencil-line" streaks.

Leaf scald | Sugarcane
DISEASE: Leaf scald
HOST: Sugarcane (Saccharum officinarum)
PATHOGEN: Xanthomonas albilineans
SOURCE: R. Birch
DISEASE: Leaf scald
HOST: Sugarcane
Early stage of disease with white, "pencil-line" streaks on leaf.

Leaf scald | Sugarcane
DISEASE: Leaf scald
HOST: Sugarcane (Saccharum officinarum)
PATHOGEN: Xanthomonas albilineans
SOURCE: R. Birch
DISEASE: Leaf scald
HOST: Sugarcane
Leaf with brownish necrotic streaks, some reddish.

Leaf scald | Sugarcane
DISEASE: Leaf scald
HOST: Sugarcane (Saccharum officinarum)
PATHOGEN: Xanthomonas albilineans
SOURCE: D. Teakle
DISEASE: Leaf scald
HOST: Sugarcane
Advanced stage of disease with brownish red necrotic streaks covering most of the leaf surface.

Leaf scald | Sugarcane
DISEASE: Leaf scald
HOST: Sugarcane (Saccharum officinarum)
PATHOGEN: Xanthomonas albilineans
SOURCE: S. Schenk