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: Holcus spot
HOST: Corn (Maize)
Corn leaf with chlorotic spots.

Holcus spot | Corn (Maize)
DISEASE: Holcus spot
HOST: Corn (Maize) (Zea mays)
PATHOGEN: Pseudomonas syringae pv. syringae
SOURCE: L. Claflin
DISEASE: Western wetwood
HOST: Elm
Spokelike, discolored extensions that expanded into sapwood, following an injection with a fungicide. The causal agent is not known but symptoms are associated with bacteria and yeast.

Western wetwood | Elm
DISEASE: Western wetwood
HOST: Elm (Ulmus americana)
PATHOGEN: Causal agent unknown
SOURCE: W. Sinclair