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 mosaic
HOST: Wheat
Diseased leaves with mosaic pattern exhibiting various amounts of yellowing. Leaves were artificially inoculated by vacuum infiltration.

Bacterial mosaic | Wheat
DISEASE: Bacterial mosaic
HOST: Wheat (Triticum aestivum)
PATHOGEN: Clavibacter michiganensis subsp. tessellarius
SOURCE: A. Vidaver
DISEASE: Blister spot
HOST: Apple
Fruit with water-soaked spots.

Blister spot | Apple
DISEASE: Blister spot
HOST: Apple (Malus domestica)
PATHOGEN: Pseudomonas syringae pv. papulans
SOURCE: T. Burr
DISEASE: Blister spot
HOST: Apple
Water-soaked blister spots on leaves of blighted twig.

Blister spot | Apple
DISEASE: Blister spot
HOST: Apple (Malus domestica)
PATHOGEN: Pseudomonas syringae pv. papulans
SOURCE: T. Burr
DISEASE: Blister spot
HOST: Apple
Apple with brownish blister spots.

Blister spot | Apple
DISEASE: Blister spot
HOST: Apple (Malus domestica 'Mutsu')
PATHOGEN: Pseudomonas syringae pv. papulans
SOURCE: S. Thomson