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: Aster yellows
HOST: Barley
Infection by this phytoplasm causes twisted awns and sterile florets.

Aster yellows | Barley
DISEASE: Aster yellows
HOST: Barley (Hordeum vulgare)
PATHOGEN: 'Candidatus Phytoplasma asteris'
PATHOGEN SYNONYM: Phytoplasma Aster yellows group
SOURCE: E. Banttari
DISEASE: Aster yellows
HOST: Barley
Small necrotic spots on lower leaves and red coalescing streaks on upper leaves.

Aster yellows | Barley
DISEASE: Aster yellows
HOST: Barley (Hordeum vulgare)
PATHOGEN: 'Candidatus Phytoplasma asteris'
PATHOGEN SYNONYM: Phytoplasma Aster yellows group
SOURCE: E. Banttari
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
DISEASE: Bacterial blight
HOST: Anthurium
Sliced petiole with discolored cortical tissues, indicative of systemic infection.

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