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: Pierce's disease
HOST: Grape
Leaves with bright yellow, chlorotic areas with dead, dry, necrotic adjacent tissues.
Pierce's disease | Grape
DISEASE: Pierce's disease
HOST: Grape (Vitis vinifera)
PATHOGEN: Xylella fastidiosa
SOURCE: J. Clark, S. Purcell
DISEASE: Pierce's disease
HOST: Grape
Early symptoms of Pierce's disease on leaves. Symptoms vary greatly among cultivars.
Pierce's disease | Grape
DISEASE: Pierce's disease
HOST: Grape (Vitis vinifera 'Chardonnay')
PATHOGEN: Xylella fastidiosa
SOURCE: J. Clark, S. Purcell
DISEASE: Pierce's disease
HOST: Grape
Late-season wood on diseased canes fail to mature, leaving green "islands" of tissue surrounded by dark brown, mature wood.
Pierce's disease | Grape
DISEASE: Pierce's disease
HOST: Grape (Vitis vinifera 'Fiesta')
PATHOGEN: Xylella fastidiosa
SOURCE: S. Purcell
DISEASE: Stewart's wilt
HOST: Corn (Maize)
Wilted seedlings resulting from systemic invasion.
Stewart's wilt | Corn (Maize)
DISEASE: Stewart's wilt
HOST: Corn (Maize) (Zea mays)
PATHOGEN: Pantoea stewartii subsp. stewartii
PATHOGEN SYNONYM: Erwinia stewartii
SOURCE: D. White
DISEASE: Stewart's wilt
HOST: Corn (Maize)
Leaf blight is the dominant symptom of this disease. Lesions begin as gray-green to yellow in color and turn brown in time.
Stewart's wilt | Corn (Maize)
DISEASE: Stewart's wilt
HOST: Corn (Maize) (Zea mays)
PATHOGEN: Pantoea stewartii subsp. stewartii
PATHOGEN SYNONYM: Erwinia stewartii
SOURCE: D. White
DISEASE: Stewart's wilt
HOST: Corn (Maize)
Flea beetle and scars caused by feeding damage. The beetle is a vector and is an overwintering site for the bacterium.
Stewart's wilt | Corn (Maize)
DISEASE: Stewart's wilt
HOST: Corn (Maize) (Zea mays)
PATHOGEN: Pantoea stewartii subsp. stewartii
PATHOGEN SYNONYM: Erwinia stewartii
SOURCE: D. White
DISEASE: Stewart's wilt
HOST: Corn (Maize)
Young wilted plant with pale green and yellow streaks on leaves.
Stewart's wilt | Corn (Maize)
DISEASE: Stewart's wilt
HOST: Corn (Maize) (Zea mays)
PATHOGEN: Pantoea stewartii subsp. stewartii
PATHOGEN SYNONYM: Erwinia stewartii
SOURCE: D. White