DISEASE: Apple proliferation
HOST: Apple
Enlarged stipules on leaf. Witches'-brooms, rosettes, and enlarged stipules are the most reliable symptoms for identification.
Apple proliferation | Apple
DISEASE: Apple proliferation
HOST: Apple (Malus domestica 'Granny Smith')
PATHOGEN: 'Candidatus Phytoplasma mali'
PATHOGEN SYNONYM: Phytoplasma Apple proliferation group
SOURCE: M. Wolf, W. Schweigkofler
DISEASE: Aster yellows
HOST: Squash
Diagnostic characteristics for the disease are yellowing of young leaves, proliferation of secondary shoots, and rigid erect habit. Leaves are misshapen and smaller than normal and have stiff, thick laminae.
Aster yellows | Squash
DISEASE: Aster yellows
HOST: Squash (Cucurbita sp.)
PATHOGEN: 'Candidatus Phytoplasma asteris'
PATHOGEN SYNONYM: Phytoplasma Aster yellows group
SOURCE: S. Miller
DISEASE: Bacterial wilt
HOST: Squash
Field with severe symptoms of wilt. Foliage often is chlorotic and leaf margins may be chlorotic and necrotic before plant death. Bacterial ooze may be seen streaming from the xylem when infected stems are cut.
Bacterial wilt | Squash
DISEASE: Bacterial wilt
HOST: Squash (Cucurbita maxima)
PATHOGEN: Erwinia tracheiphila
SOURCE: B. Jacobsen, M. Shurtleff
DISEASE: Blister spot
HOST: Apple
Fruit with water-soaked spots.
Blister spot | Apple
DISEASE: Blister spot
HOST: Apple (Malus domestica)
PATHOGEN: Pseudomonas syringae pv. papulans
SOURCE: T. Burr
DISEASE: Blister spot
HOST: Apple
Water-soaked blister spots on leaves of blighted twig.
Blister spot | Apple
DISEASE: Blister spot
HOST: Apple (Malus domestica)
PATHOGEN: Pseudomonas syringae pv. papulans
SOURCE: T. Burr
DISEASE: Blister spot
HOST: Apple
Apple with brownish blister spots.
Blister spot | Apple
DISEASE: Blister spot
HOST: Apple (Malus domestica 'Mutsu')
PATHOGEN: Pseudomonas syringae pv. papulans
SOURCE: S. Thomson
DISEASE: Blister spot
HOST: Apple
Late stage of blister spot. The purplish black lesions are associated with lenticels and stomata.
Blister spot | Apple
DISEASE: Blister spot
HOST: Apple (Malus domestica 'Crispin')
PATHOGEN: Pseudomonas syringae pv. papulans
SOURCE: T. Burr
DISEASE: Blossom blast
HOST: Apple
Many dead, shriveled flowers and young shoots. It differs from fire blight, with infections being relatively localized with the appearance of being "blasted".
Blossom blast | Apple
DISEASE: Blossom blast
HOST: Apple (Malus domestica)
PATHOGEN: Pseudomonas syringae pv. syringae
SOURCE: M. Schroth
DISEASE: Crown gall
HOST: Apple
Crown gall of apple.
Crown gall | Apple
DISEASE: Crown gall
HOST: Apple (Malus domestica)
PATHOGEN: Agrobacterium tumefaciens
PATHOGEN SYNONYM: Rhizobium sp.
SOURCE: H. Sawada, M. Goto