DISEASE: Bacterial leaf spot
HOST: Citrus (sp. unknown)
Leaf with flat, spreading lesions.

Bacterial leaf spot | Citrus (sp. unknown)
DISEASE: Bacterial leaf spot
HOST: Citrus (sp. unknown) (Citrus sp.)
PATHOGEN: Xanthomonas alfalfae subsp. citrumelonis
PATHOGEN SYNONYM: Xanthomonas alfalfae subsp. citrumelo
SOURCE: J. H. Graham
DISEASE: Blood disease
HOST: Banana
Yellow leaves of dying plant.

Blood disease | Banana
DISEASE: Blood disease
HOST: Banana (Musa sp.)
PATHOGEN: Ralstonia solanacearum species complex
PATHOGEN SYNONYM: Ralstonia solanacearum (Phylotype IV)
SOURCE: I. Buddenhagen
DISEASE: Blood disease
HOST: Banana
Cross sections of diseased fruit with reddish discoloration and bacterial ooze.

Blood disease | Banana
DISEASE: Blood disease
HOST: Banana (Musa sp.)
PATHOGEN: Ralstonia solanacearum species complex
PATHOGEN SYNONYM: Ralstonia solanacearum (Phylotype IV)
SOURCE: I. Buddenhagen
DISEASE: Blood disease
HOST: Banana
Longitudinal sections (right) exposing reddish brown discoloration of infected fruit.

Blood disease | Banana
DISEASE: Blood disease
HOST: Banana (Musa sp.)
PATHOGEN: Ralstonia solanacearum species complex
PATHOGEN SYNONYM: Ralstonia solanacearum (Phylotype IV)
SOURCE: I. Buddenhagen
DISEASE: Blood disease
HOST: Banana
Diseased plant with wilt and yellowing of leaves. The disease occurs in Indonesia and is characterized by bright red discoloration of vascular tissues. It is caused by strains in the Ralstonia solanacearum species complex.

Blood disease | Banana
DISEASE: Blood disease
HOST: Banana (Musa sp.)
PATHOGEN: Ralstonia solanacearum species complex
PATHOGEN SYNONYM: Ralstonia solanacearum (Phylotype IV)
SOURCE: I. Buddenhagen
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
DISEASE: Xanthomonas leaf blight
HOST: Onion
Onions with brown, necrotic, blighted leaves.

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