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: Syringae seedling blight and leaf spot
HOST: Pepper
Blight lesions (on transplants) usually begin as water-soaked spots that later turn brown to black. Lesions are on cotyledons and first true leaves.
Syringae seedling blight and leaf spot | Pepper
DISEASE: Syringae seedling blight and leaf spot
HOST: Pepper (Capsicum annuum)
PATHOGEN: Pseudomonas syringae pv. syringae
SOURCE: APS
DISEASE: Wildfire (Angular leaf spot)
HOST: Tobacco
Characteristic symptoms are necrotic, brown spots with angular margins surrounded by distinct yellow halos. The halos are caused by the production of tabtoxin.
Wildfire (Angular leaf spot) | Tobacco
DISEASE: Wildfire (Angular leaf spot)
HOST: Tobacco (Nicotiana tabacum)
PATHOGEN: Pseudomonas syringae pv. tabaci
SOURCE: G. Lucas