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 blast and black pit
HOST: Citrus (Lemon)
The term "black pit" refers to black lesions on fruit, which may be specks or large, sunken pits as seen here. They also may be light tan, later becoming reddish brown to black.
Bacterial blast and black pit | Citrus (Lemon)
DISEASE: Bacterial blast and black pit
HOST: Citrus (Lemon) (Citrus limon)
PATHOGEN: Pseudomonas syringae pv. syringae
SOURCE: J. Menge
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: Brown blotch
HOST: Mushroom
Stunted fruit bodies, initial stage of disease.
Brown blotch | Mushroom
DISEASE: Brown blotch
HOST: Mushroom (Pleurotus ostreatus)
PATHOGEN: Pseudomonas tolaasii
SOURCE: K. Suyama, M. Goto
DISEASE: Brown blotch
HOST: Mushroom
Fruit bodies at advanced stage of disease.
Brown blotch | Mushroom
DISEASE: Brown blotch
HOST: Mushroom (Pleurotus ostreatus)
PATHOGEN: Pseudomonas tolaasii
SOURCE: K. Suyama, M. Goto
DISEASE: Brown blotch
HOST: Mushroom
Black discoloration of basal portions of fruit bodies. Healthy (left).
Brown blotch | Mushroom
DISEASE: Brown blotch
HOST: Mushroom (Flammulina velutipes)
PATHOGEN: Pseudomonas tolaasii
SOURCE: K. Suyama, M. Goto
DISEASE: Brown blotch
HOST: Mushroom
Black discoloration of basal portion of fruit bodies.
Brown blotch | Mushroom
DISEASE: Brown blotch
HOST: Mushroom (Flammulina velutipes)
PATHOGEN: Pseudomonas tolaasii
SOURCE: K. Suyama, M. Goto
DISEASE: Brown blotch
HOST: Mushroom
Mushrooms with rotted, brownish discoloration of infected areas.
Brown blotch | Mushroom
DISEASE: Brown blotch
HOST: Mushroom (Agaricus campestris)
PATHOGEN: Pseudomonas tolaasii
SOURCE: J. Young
DISEASE: Citrus canker
HOST: Citrus (Lemon)
Lower leaf with raised, corkylike lesions surrounded by dark brown halos, one of the diagnostic symptoms of citrus canker.
Citrus canker | Citrus (Lemon)
DISEASE: Citrus canker
HOST: Citrus (Lemon) (Citrus limon)
PATHOGEN: Xanthomonas citri subsp. citri
PATHOGEN SYNONYM: Xanthomonas citri
SOURCE: T. Gottwald