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: Periwinkle yellows
HOST: Periwinkle
Leaves with characteristic yellow and chlorotic appearance. Yellowing is first associated with veins.
Periwinkle yellows | Periwinkle
DISEASE: Periwinkle yellows
HOST: Periwinkle (Vinca sp.)
PATHOGEN: 'Candidatus Phytoplasma' sp.
PATHOGEN SYNONYM: Phytoplasma (undefined)
SOURCE: R. McCoy, M. Davis
DISEASE: Wildfire
HOST: Soybean
Close-up of lesions with large, yellow halos.
Wildfire | Soybean
DISEASE: Wildfire
HOST: Soybean (Glycine max)
PATHOGEN: Pseudomonas syringae pv. tabaci
SOURCE: J. Forsberg, M. Shurtleff
DISEASE: Wildfire
HOST: Soybean
Leaf with brown necrotic spots with yellow halos. During dry weather, lesions become dry and dead areas tear off, leaving a tattered appearance.
Wildfire | Soybean
DISEASE: Wildfire
HOST: Soybean (Glycine max)
PATHOGEN: Pseudomonas syringae pv. tabaci
SOURCE: D. Teakle