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 canker and blast
HOST: Apricot
Young infected twig with droplets of bacterial ooze on stem.

Bacterial canker and blast | Apricot
DISEASE: Bacterial canker and blast
HOST: Apricot (Prunus armeniaca 'Moorpark')
PATHOGEN: Pseudomonas syringae pv. syringae
SOURCE: J. Young
DISEASE: Bacterial canker and blast
HOST: Apricot
Bacterial canker has many symptoms. Typical symptoms are brown, sometimes reddish brown, internal tissues and rough, cracked bark.

Bacterial canker and blast | Apricot
DISEASE: Bacterial canker and blast
HOST: Apricot (Prunus armeniaca 'Moorpark')
PATHOGEN: Pseudomonas syringae pv. syringae
SOURCE: J. Young
DISEASE: Bacterial canker and blast
HOST: Apricot
Infected apricot with sparse foliage (some twigs with no foliage) and a discolored area exposed where bark was removed.

Bacterial canker and blast | Apricot
DISEASE: Bacterial canker and blast
HOST: Apricot (Prunus armeniaca 'Moorpark')
PATHOGEN: Pseudomonas syringae pv. syringae
SOURCE: J. Young
DISEASE: Bacterial canker and blast
HOST: Apricot
Fruit spot phase with numerous reddish necrotic spots.

Bacterial canker and blast | Apricot
DISEASE: Bacterial canker and blast
HOST: Apricot (Prunus armeniaca 'Moorpark')
PATHOGEN: Pseudomonas syringae pv. syringae
SOURCE: J. Young
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