DISEASE: Ash yellows
HOST: Ash
Ash sapling with basal sprouts and chlorotic leaves.
Ash yellows | Ash
DISEASE: Ash yellows
HOST: Ash (Fraxinus pennsylvanica)
PATHOGEN: 'Candidatus Phytoplasma fraxini'
PATHOGEN SYNONYM: Phytoplasma Ash yellows group
SOURCE: W. Sinclair
DISEASE: Ash yellows
HOST: Ash
Witches'-broom at base of declining tree.
Ash yellows | Ash
DISEASE: Ash yellows
HOST: Ash (Fraxinus velutina)
PATHOGEN: 'Candidatus Phytoplasma fraxini'
PATHOGEN SYNONYM: Phytoplasma Ash yellows group
SOURCE: W. Sinclair
DISEASE: Ash yellows
HOST: Ash
Forest of declining trees, some chlorotic and others with dieback.
Ash yellows | Ash
DISEASE: Ash yellows
HOST: Ash (Fraxinus americana)
PATHOGEN: 'Candidatus Phytoplasma fraxini'
PATHOGEN SYNONYM: Phytoplasma Ash yellows group
SOURCE: W. Sinclair
DISEASE: Ash yellows
HOST: Ash
White ash with deliquescent branching.
Ash yellows | Ash
DISEASE: Ash yellows
HOST: Ash (Fraxinus americana)
PATHOGEN: 'Candidatus Phytoplasma fraxini'
PATHOGEN SYNONYM: Phytoplasma Ash yellows group
SOURCE: W. Sinclair
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: Xanthomonas leaf blight
HOST: Onion
This was the first photo of onion leaf blight, which was considered a controversial finding for 10 years until an outbreak occurred in the West Indies.
Xanthomonas leaf blight | Onion
DISEASE: Xanthomonas leaf blight
HOST: Onion (Allium cepa)
PATHOGEN: Xanthomonas axonopodis pv. allii
PATHOGEN SYNONYM: Xanthomonas campestris pv. allii
SOURCE: A. Alvarez
DISEASE: Xanthomonas leaf blight
HOST: Onion
Diseased leaf with necrotic internal tissues.
Xanthomonas leaf blight | Onion
DISEASE: Xanthomonas leaf blight
HOST: Onion (Allium cepa)
PATHOGEN: Xanthomonas axonopodis pv. allii
PATHOGEN SYNONYM: Xanthomonas campestris pv. allii
SOURCE: A. Alvarez