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 blast
HOST: Pear
The bacterium infects all flower parts and may spread and kill the entire spur.
Bacterial blast | Pear
DISEASE: Bacterial blast
HOST: Pear (Pyrus communis)
PATHOGEN: Pseudomonas syringae pv. syringae
SOURCE: W. Sinclair
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