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: 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
DISEASE: Xanthomonas leaf spot
HOST: Cabbage
Cabbage leaf with small lesions. Lesions may enlarge and coalesce, causing distortion. Stem lesions are black and sunken and may cause death of the plants.

Xanthomonas leaf spot | Cabbage
DISEASE: Xanthomonas leaf spot
HOST: Cabbage (Brassica oleracea var. capitata)
PATHOGEN: Xanthomonas campestris pv. raphani
SOURCE: R. Gitaitis