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 heart rot
HOST: Palm
Palm with advanced stage of heart rot. Symptoms of mature palms include rapid browning and desiccation of foliage, rot of roots and buds, and aborted fruits.

Bacterial heart rot | Palm
DISEASE: Bacterial heart rot
HOST: Palm (Cocos nucifera)
PATHOGEN: Phytomonas sp.
SOURCE: R. McCoy, M. Davis
DISEASE: Goss's bacterial wilt and blight
HOST: Corn (Maize)
Wilted, dying plants. Leaves have gray to light yellow stripes and irregular margins that follow leaf veins. Systemically infected plants usually have orange vascular bundles.

Goss's bacterial wilt and blight | Corn (Maize)
DISEASE: Goss's bacterial wilt and blight
HOST: Corn (Maize) (Zea mays)
PATHOGEN: Clavibacter michiganensis subsp. nebraskensis
PATHOGEN SYNONYM: Corynebacterium nebraskense
SOURCE: A. Vidaver
DISEASE: Goss's bacterial wilt and blight
HOST: Corn (Maize)
The disease causes necrotic leaf lesions, which typically have dark flecks (freckles) within the lesions (not seen here).

Goss's bacterial wilt and blight | Corn (Maize)
DISEASE: Goss's bacterial wilt and blight
HOST: Corn (Maize) (Zea mays)
PATHOGEN: Clavibacter michiganensis subsp. nebraskensis
PATHOGEN SYNONYM: Corynebacterium nebraskense
SOURCE: A. Vidaver