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 blight (Brown stem)
HOST: Celery
Lesions are necrotic and circular to angular. Some have yellowish halos. Older lesions become brown and dry.

Bacterial blight (Brown stem) | Celery
DISEASE: Bacterial blight (Brown stem)
HOST: Celery (Apium graveolens)
PATHOGEN: Pseudomonas cichorii
SOURCE: R. Raid
DISEASE: Bacterial blight (Brown stem)
HOST: Celery
Ooze from lesion on celery leaf.

Bacterial blight (Brown stem) | Celery
DISEASE: Bacterial blight (Brown stem)
HOST: Celery (Apium graveolens)
PATHOGEN: Pseudomonas cichorii
SOURCE: R. Raid
DISEASE: Bacterial blight (Brown stem)
HOST: Celery
Characteristic brown discoloration of petioles, which is more evident on inside of petiole close to the crown. Parenchyma tissues are firm and brown.

Bacterial blight (Brown stem) | Celery
DISEASE: Bacterial blight (Brown stem)
HOST: Celery (Apium graveolens)
PATHOGEN: Pseudomonas cichorii
SOURCE: K. Pernezny
DISEASE: Bacterial blight
HOST: Anthurium
Leaf with necrotic lesions surrounded by chlorotic zones, indicative of stomatal invasion.

Bacterial blight | Anthurium
DISEASE: Bacterial blight
HOST: Anthurium (Anthurium andraeanum)
PATHOGEN: Xanthomonas axonopodis pv. dieffenbachiae
PATHOGEN SYNONYM: Xanthomonas campestris pv. dieffenbachiae
SOURCE: A. Alvarez
DISEASE: Bacterial blight
HOST: Anthurium
Chlorosis of leaf margins, an early stage of disease.

Bacterial blight | Anthurium
DISEASE: Bacterial blight
HOST: Anthurium (Anthurium andraeanum)
PATHOGEN: Xanthomonas axonopodis pv. dieffenbachiae
PATHOGEN SYNONYM: Xanthomonas campestris pv. dieffenbachiae
SOURCE: A. Alvarez
DISEASE: Bacterial blight
HOST: Anthurium
Necrotic lesions surrounded by chlorotic zones, indicative of hydathode invasion.

Bacterial blight | Anthurium
DISEASE: Bacterial blight
HOST: Anthurium (Anthurium andraeanum)
PATHOGEN: Xanthomonas axonopodis pv. dieffenbachiae
PATHOGEN SYNONYM: Xanthomonas campestris pv. dieffenbachiae
SOURCE: W. Nishijima
DISEASE: Bacterial blight
HOST: Anthurium
Leaves with necrotic margins.

Bacterial blight | Anthurium
DISEASE: Bacterial blight
HOST: Anthurium (Anthurium andraeanum)
PATHOGEN: Xanthomonas axonopodis pv. dieffenbachiae
PATHOGEN SYNONYM: Xanthomonas campestris pv. dieffenbachiae
SOURCE: W. Nishijima
DISEASE: Bacterial blight
HOST: Anthurium
Chlorotic leaf with signs of water stress caused by infection of vascular system.

Bacterial blight | Anthurium
DISEASE: Bacterial blight
HOST: Anthurium (Anthurium andraeanum)
PATHOGEN: Xanthomonas axonopodis pv. dieffenbachiae
PATHOGEN SYNONYM: Xanthomonas campestris pv. dieffenbachiae
SOURCE: W. Nishijima