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: Rugose leaf curl
HOST: Clover
Two rugose, distorted white clover leaves and a healthy leaf. Rugose leaf curl is caused by an unidentified phloem-infecting bacterium.

Rugose leaf curl | Clover
DISEASE: Rugose leaf curl
HOST: Clover (Trifolium repens)
PATHOGEN: Phloem-infecting bacterium
SOURCE: D. Teakle
DISEASE: Sour skin
HOST: Onion
Symptoms of sour skin are characterized by slimy, pale yellow to light brown decay.

Sour skin | Onion
DISEASE: Sour skin
HOST: Onion (Allium cepa)
PATHOGEN: Burkholderia cepacia
PATHOGEN SYNONYM: Pseudomonas cepacia
SOURCE: Dep. of Agric. & Agri-Food, Government of Canada
DISEASE: Sour skin
HOST: Onion
Characteristic pale yellow to browning of infected area.

Sour skin | Onion
DISEASE: Sour skin
HOST: Onion (Allium cepa)
PATHOGEN: Burkholderia cepacia
PATHOGEN SYNONYM: Pseudomonas cepacia
SOURCE: R. Gitaitis
DISEASE: Witches'-broom
HOST: Lilac
Lilac with broomlike symptoms and dead twigs.

Witches'-broom | Lilac
DISEASE: Witches'-broom
HOST: Lilac (Syringa josiflexa 'Royalty')
PATHOGEN: 'Candidatus Phytoplasma fraxini'
PATHOGEN SYNONYM: Phytoplasma Ash yellows group
SOURCE: C. Hibben, W. Sinclair