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: Elm leaf scorch
HOST: Elm
Diseased tree with scorch at leaf margins.

Elm leaf scorch | Elm
DISEASE: Elm leaf scorch
HOST: Elm (Ulmus americana)
PATHOGEN: Xylella fastidiosa
SOURCE: J. Sherald, M. Shurtleff
DISEASE: Elm leaf scorch
HOST: Elm
Severely diseased tree with dieback and scorched leaves.

Elm leaf scorch | Elm
DISEASE: Elm leaf scorch
HOST: Elm (Ulmus americana)
PATHOGEN: Xylella fastidiosa
SOURCE: W. Sinclair
DISEASE: Xanthomonas leaf blight
HOST: Onion
This was the first photo of onion leaf blight, which was considered a controversial finding for 10 years until an outbreak occurred in the West Indies.

Xanthomonas leaf blight | Onion
DISEASE: Xanthomonas leaf blight
HOST: Onion (Allium cepa)
PATHOGEN: Xanthomonas axonopodis pv. allii
PATHOGEN SYNONYM: Xanthomonas campestris pv. allii
SOURCE: A. Alvarez
DISEASE: Xanthomonas leaf blight
HOST: Onion
Diseased leaf with necrotic internal tissues.

Xanthomonas leaf blight | Onion
DISEASE: Xanthomonas leaf blight
HOST: Onion (Allium cepa)
PATHOGEN: Xanthomonas axonopodis pv. allii
PATHOGEN SYNONYM: Xanthomonas campestris pv. allii
SOURCE: A. Alvarez