DISEASE: Apple proliferation
HOST: Apple
Spring form of the adult black-veined psyllid, Cacopsylla melanoneura, a vector of apple proliferation. In winter, adults are more greenish in color.

Apple proliferation | Apple
DISEASE: Apple proliferation
HOST: Apple (Malus domestica)
PATHOGEN: 'Candidatus Phytoplasma mali'
PATHOGEN SYNONYM: Phytoplasma Apple proliferation group
SOURCE: M. Wolf, W. Schweigkofler
DISEASE: Apple proliferation
HOST: Apple
Typical apple proliferation symptom of witches'-broom resulting from suppression of apical dominance and growth of dormant axillary buds. Branches are not usually bent down as shown here.

Apple proliferation | Apple
DISEASE: Apple proliferation
HOST: Apple (Malus domestica)
PATHOGEN: 'Candidatus Phytoplasma mali'
PATHOGEN SYNONYM: Phytoplasma Apple proliferation group
SOURCE: M. Wolf, W. Schweigkofler
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 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