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 rot
HOST: Dahlia
Longitudinal section of dahlia with discolored, rotted tissues.

Bacterial rot | Dahlia
DISEASE: Bacterial rot
HOST: Dahlia (Dahlia sp.)
PATHOGEN: Dickeya sp.
PATHOGEN SYNONYM: Erwinia chrysanthemi
SOURCE: J. Young
DISEASE: Bacterial rot
HOST: Dracaena
Rot at base of leaves.

Bacterial rot | Dracaena
DISEASE: Bacterial rot
HOST: Dracaena (Dracaena deremensis)
PATHOGEN: Dickeya sp.
PATHOGEN SYNONYM: Erwinia chrysanthemi
SOURCE: A. Alvarez
DISEASE: Bacterial rot
HOST: Dracaena
Systemic rot throughout central stems.

Bacterial rot | Dracaena
DISEASE: Bacterial rot
HOST: Dracaena (Dracaena deremensis)
PATHOGEN: Dickeya sp.
PATHOGEN SYNONYM: Erwinia chrysanthemi
SOURCE: A. Chase
DISEASE: Bacterial rot
HOST: Fennel
Soft rot of fennel.

Bacterial rot | Fennel
DISEASE: Bacterial rot
HOST: Fennel (Foeniculum vulgare)
PATHOGEN: Dickeya sp.
PATHOGEN SYNONYM: Erwinia chrysanthemi
SOURCE: R. 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