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: Aster yellows
HOST: Onion
Infected plants with yellowish, malformed leaves.

Aster yellows | Onion
DISEASE: Aster yellows
HOST: Onion (Allium cepa)
PATHOGEN: 'Candidatus Phytoplasma asteris'
PATHOGEN SYNONYM: Phytoplasma Aster yellows group
SOURCE: R. Rowe
DISEASE: Aster yellows
HOST: Onion
Onion flower with unusual symptoms (left) compared with healthy inflorescence (right). Flowers are distorted and often have abnormally long pedicels. Young leaves may have yellow streaks or a general yellowing of basal portions.

Aster yellows | Onion
DISEASE: Aster yellows
HOST: Onion (Allium cepa)
PATHOGEN: 'Candidatus Phytoplasma asteris'
PATHOGEN SYNONYM: Phytoplasma Aster yellows group
SOURCE: R. Raabe
DISEASE: Bacterial dieback of nectarine
HOST: Nectarine
Dark cankers on last year's twig. Symptoms of bacterial dieback of nectarine are identical to those of bacterial dieback of peach.

Bacterial dieback of nectarine | Nectarine
DISEASE: Bacterial dieback of nectarine
HOST: Nectarine (Prunus persica var. nucipersica)
PATHOGEN: Pseudomonas syringae pv. persicae
SOURCE: J. Young
DISEASE: Bacterial dieback of nectarine
HOST: Nectarine
Diseased young twigs.

Bacterial dieback of nectarine | Nectarine
DISEASE: Bacterial dieback of nectarine
HOST: Nectarine (Prunus persica var. nucipersica)
PATHOGEN: Pseudomonas syringae pv. persicae
SOURCE: J. Young
DISEASE: Bacterial dieback of nectarine
HOST: Nectarine
Bacterial invasion of trunk caused reddish brown discolored area. Symptoms of bacterial dieback of nectarine are identical to those of bacterial dieback of peach.

Bacterial dieback of nectarine | Nectarine
DISEASE: Bacterial dieback of nectarine
HOST: Nectarine (Prunus persica var. nucipersica)
PATHOGEN: Pseudomonas syringae pv. persicae
SOURCE: J. Young
DISEASE: Bacterial dieback of nectarine
HOST: Nectarine
Discolored vascular tissues and gummosis on infected twig.

Bacterial dieback of nectarine | Nectarine
DISEASE: Bacterial dieback of nectarine
HOST: Nectarine (Prunus persica var. nucipersica)
PATHOGEN: Pseudomonas syringae pv. persicae
SOURCE: J. Young