DISEASE: Aster yellows
HOST: Aster
Foliar symptoms of chlorosis, malformation of leaves, and phyllody.
Aster yellows | Aster
DISEASE: Aster yellows
HOST: Aster (Aster sp.)
PATHOGEN: 'Candidatus Phytoplasma asteris'
PATHOGEN SYNONYM: Phytoplasma Aster yellows group
SOURCE: R. McCoy, M. Davis
DISEASE: Aster yellows
HOST: Aster
Flowers with phyllody (left and center). Healthy flower (right).
Aster yellows | Aster
DISEASE: Aster yellows
HOST: Aster (Aster sp.)
PATHOGEN: 'Candidatus Phytoplasma asteris'
PATHOGEN SYNONYM: Phytoplasma Aster yellows group
SOURCE: R. McCoy, M. Davis
DISEASE: Aster yellows
HOST: Aster
Macrosteles sp., a leafhopper vector of aster yellows phytoplasma.
Aster yellows | Aster
DISEASE: Aster yellows
HOST: Aster (Aster sp.)
PATHOGEN: 'Candidatus Phytoplasma asteris'
PATHOGEN SYNONYM: Phytoplasma Aster yellows group
SOURCE: J. Clark, A. Purcell, M. Davis
DISEASE: Bacterial leaf spot
HOST: Pellionia
Leaves with dry, irregularly shaped lesions with corky, raised borders on upper surface.
Bacterial leaf spot | Pellionia
DISEASE: Bacterial leaf spot
HOST: Pellionia (Pellionia sp.)
PATHOGEN: Xanthomonas campestris
SOURCE: A. Chase
DISEASE: Bacterial leaf spot
HOST: Pellionia
Leaf lesions are irregular, corky, and slightly raised on lower leaf surfaces. Lesions may fall out, leaving a shot-hole appearance.
Bacterial leaf spot | Pellionia
DISEASE: Bacterial leaf spot
HOST: Pellionia (Pellionia sp.)
PATHOGEN: Xanthomonas campestris
SOURCE: H. Schwartz
DISEASE: Citrus canker
HOST: Citrus (Orange)
Leaf with leaf miner tunnels and numerous cankerlike lesions.
Citrus canker | Citrus (Orange)
DISEASE: Citrus canker
HOST: Citrus (Orange) (Citrus sinensis)
PATHOGEN: Xanthomonas citri subsp. citri
PATHOGEN SYNONYM: Xanthomonas citri
SOURCE: T. Gottwald
DISEASE: Citrus canker
HOST: Citrus (Orange)
Upper side of leaves with corky, raised lesions surrounded by yellow halos, a late stage of disease. Such infections usually are visible on lower sides of leaves first and soon after on upper sides.
Citrus canker | Citrus (Orange)
DISEASE: Citrus canker
HOST: Citrus (Orange) (Citrus sinensis)
PATHOGEN: Xanthomonas citri subsp. citri
PATHOGEN SYNONYM: Xanthomonas citri
SOURCE: J. H. Graham
DISEASE: Citrus canker
HOST: Citrus (Orange)
Yellowish halos are seen around lesions on the upper leaf surface, whereas lesions on the lower surface are more corky in appearance and have sunken centers without halos.
Citrus canker | Citrus (Orange)
DISEASE: Citrus canker
HOST: Citrus (Orange) (Citrus sinensis)
PATHOGEN: Xanthomonas citri subsp. citri
PATHOGEN SYNONYM: Xanthomonas citri
SOURCE: J. Young
DISEASE: Citrus canker
HOST: Citrus (Orange)
Leaves with necrotic lesions and yellow halos.
Citrus canker | Citrus (Orange)
DISEASE: Citrus canker
HOST: Citrus (Orange) (Citrus sinensis)
PATHOGEN: Xanthomonas citri subsp. citri
PATHOGEN SYNONYM: Xanthomonas citri
SOURCE: T. Gottwald