DISEASE: Alfalfa dwarf
HOST: Alfalfa
Alfalfa dwarf is characterized by stunted plants (left), usually dark blue-green in color. Xylem tissues become brown, especially when exposed to air.

Alfalfa dwarf | Alfalfa
DISEASE: Alfalfa dwarf
HOST: Alfalfa (Medicago sativa)
PATHOGEN: Xylella fastidiosa
SOURCE: R. M. Davis
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: Syringae leaf spot
HOST: Tomato
Leaves with brown necrotic lesions and chlorotic margins. Symptoms vary greatly among cultivars. Some have black or brown lesions with bright yellow, chlorotic areas and others do not have yellowing.

Syringae leaf spot | Tomato
DISEASE: Syringae leaf spot
HOST: Tomato (Lycopersicon esculentum)
PATHOGEN: Pseudomonas syringae pv. syringae
SOURCE: R. Gitaitis