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: Bacterial leaf spot (Head rot)
HOST: Cauliflower
Leaves with tiny lesions surrounded by large halos.
Bacterial leaf spot (Head rot) | Cauliflower
DISEASE: Bacterial leaf spot (Head rot)
HOST: Cauliflower (Brassica oleracea var. botrytis)
PATHOGEN: Pseudomonas syringae pv. maculicola
SOURCE: R. Campbell
DISEASE: Bacterial leaf spot (Head rot)
HOST: Cauliflower
Section of a cauliflower head with discolored, infected tissues.
Bacterial leaf spot (Head rot) | Cauliflower
DISEASE: Bacterial leaf spot (Head rot)
HOST: Cauliflower (Brassica oleracea var. botrytis)
PATHOGEN: Pseudomonas syringae pv. maculicola
SOURCE: R. Campbell
DISEASE: Black rot
HOST: Cauliflower
Brown, necrotic, rotted areas on flower parts and typical V-shaped necrotic areas on leaf margins.
Black rot | Cauliflower
DISEASE: Black rot
HOST: Cauliflower (Brassica oleracea var. botrytis)
PATHOGEN: Xanthomonas campestris pv. campestris
SOURCE: B. Jacobsen, M. Shurtleff
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