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 speck
HOST: Tomato
Leaf with typical brown to black lesions without halos, an early stage of disease.

Bacterial speck | Tomato
DISEASE: Bacterial speck
HOST: Tomato (Lycopersicon esculentum)
PATHOGEN: Pseudomonas syringae pv. tomato
SOURCE: S. Thomson
DISEASE: Bacterial speck
HOST: Tomato
Leaves with spots, some surrounded by chlorotic zones.

Bacterial speck | Tomato
DISEASE: Bacterial speck
HOST: Tomato (Lycopersicon esculentum)
PATHOGEN: Pseudomonas syringae pv. tomato
SOURCE: R. Gitaitis
DISEASE: Bacterial speck
HOST: Tomato
Curling leaves with large, blackish lesions. Later, yellowing occurs around lesions.

Bacterial speck | Tomato
DISEASE: Bacterial speck
HOST: Tomato (Lycopersicon esculentum)
PATHOGEN: Pseudomonas syringae pv. tomato
SOURCE: M. Schroth
DISEASE: Bacterial speck
HOST: Tomato
Infection of flowers, peduncles, and stems.

Bacterial speck | Tomato
DISEASE: Bacterial speck
HOST: Tomato (Lycopersicon esculentum)
PATHOGEN: Pseudomonas syringae pv. tomato
SOURCE: D. Cupples
DISEASE: Bacterial speck
HOST: Tomato
Field view of severely diseased plants.

Bacterial speck | Tomato
DISEASE: Bacterial speck
HOST: Tomato (Lycopersicon esculentum)
PATHOGEN: Pseudomonas syringae pv. tomato
SOURCE: M. Schroth
DISEASE: Bacterial speck
HOST: Tomato
Green fruit with small, sunken, black lesions. Raised centers are surrounded by dark green halos.

Bacterial speck | Tomato
DISEASE: Bacterial speck
HOST: Tomato (Lycopersicon esculentum)
PATHOGEN: Pseudomonas syringae pv. tomato
SOURCE: S. Thomson
DISEASE: Bacterial speck
HOST: Tomato
Ripe fruit with raised lesions.

Bacterial speck | Tomato
DISEASE: Bacterial speck
HOST: Tomato (Lycopersicon esculentum)
PATHOGEN: Pseudomonas syringae pv. tomato
SOURCE: M. Schroth
DISEASE: Bacterial stalk and top rot
HOST: Corn (Maize)
Corn at intermediate stage of disease development.

Bacterial stalk and top rot | Corn (Maize)
DISEASE: Bacterial stalk and top rot
HOST: Corn (Maize) (Zea mays)
PATHOGEN: Dickeya zeae
PATHOGEN SYNONYM: Erwinia chrysanthemi pv. zeae
SOURCE: A. Alvarez