DISEASE: Alfalfa dwarf
HOST: Alfalfa
Alfalfa dwarf is characterized by stunted plants (left), usually dark blue-green in color. Xylem tissues become brown, especially when exposed to air.
Alfalfa dwarf | Alfalfa
DISEASE: Alfalfa dwarf
HOST: Alfalfa (Medicago sativa)
PATHOGEN: Xylella fastidiosa
SOURCE: R. M. Davis
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: Apple proliferation
HOST: Apple
Enlarged stipules are a characteristic symptom of the disease.
Apple proliferation | Apple
DISEASE: Apple proliferation
HOST: Apple (Malus domestica 'Golden Delicious')
PATHOGEN: 'Candidatus Phytoplasma mali'
PATHOGEN SYNONYM: Phytoplasma Apple proliferation group
SOURCE: W. Schweigkofler
DISEASE: Apple proliferation
HOST: Apple
Branch with shortened internodes that cause rosettes and witches’-brooms, typical of this disease.
Apple proliferation | Apple
DISEASE: Apple proliferation
HOST: Apple (Malus domestica 'Golden Delicious')
PATHOGEN: 'Candidatus Phytoplasma mali'
PATHOGEN SYNONYM: Phytoplasma Apple proliferation group
SOURCE: L. Kunze
DISEASE: Apple proliferation
HOST: Apple
Small apples are a characteristic symptom. The size of apples is best noted by comparing them with adjacent leaves.
Apple proliferation | Apple
DISEASE: Apple proliferation
HOST: Apple (Malus domestica 'Golden Delicious')
PATHOGEN: 'Candidatus Phytoplasma mali'
PATHOGEN SYNONYM: Phytoplasma Apple proliferation group
SOURCE: J. Vigl, W. Schweigkofler
DISEASE: Apple proliferation
HOST: Apple
Enlarged stipules are typical with some cultivars infected by the phytoplasma.
Apple proliferation | Apple
DISEASE: Apple proliferation
HOST: Apple (Malus domestica 'Golden Delicious')
PATHOGEN: 'Candidatus Phytoplasma mali'
PATHOGEN SYNONYM: Phytoplasma Apple proliferation group
SOURCE: J. Vigl, W. Schweigkofler
DISEASE: Apple proliferation
HOST: Apple
Leaves of diseased trees have a reddish color in late summer and early autumn.
Apple proliferation | Apple
DISEASE: Apple proliferation
HOST: Apple (Malus domestica 'Golden Delicious')
PATHOGEN: 'Candidatus Phytoplasma mali'
PATHOGEN SYNONYM: Phytoplasma Apple proliferation group
SOURCE: M. Wolf, W. Schweigkofler
DISEASE: Apple proliferation
HOST: Apple
Diseased foliage with reddish appearance of leaves.
Apple proliferation | Apple
DISEASE: Apple proliferation
HOST: Apple (Malus domestica 'Golden Delicious')
PATHOGEN: 'Candidatus Phytoplasma mali'
PATHOGEN SYNONYM: Phytoplasma Apple proliferation group
SOURCE: M. Wolf, W. Schweigkofler