DISEASE: Bacterial leaf spot
HOST: Snapdragon
Leaves with large necrotic areas with brownish centers and purplish margins. Lesions are slightly sunken.

Bacterial leaf spot | Snapdragon
DISEASE: Bacterial leaf spot
HOST: Snapdragon (Antirrhinum majus)
PATHOGEN: Pseudomonas syringae pv. antirrhini
SOURCE: R. Raabe
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: Corn stunt
HOST: Corn (Maize)
Chlorosis of leaf margins, the first symptom of disease.

Corn stunt | Corn (Maize)
DISEASE: Corn stunt
HOST: Corn (Maize) (Zea mays)
PATHOGEN: Spiroplasma kunkelii
SOURCE: T. Tsai, M. Davis
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