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
HOST: Pear
The bacterium infects all flower parts and may spread and kill the entire spur.
Bacterial blast | Pear
DISEASE: Bacterial blast
HOST: Pear (Pyrus communis)
PATHOGEN: Pseudomonas syringae pv. syringae
SOURCE: W. Sinclair
DISEASE: Bacterial stem rot
HOST: Dieffenbachia
Dieffenbachia with rot and decay of stem and leaf tissues.
Bacterial stem rot | Dieffenbachia
DISEASE: Bacterial stem rot
HOST: Dieffenbachia (Dieffenbachia seguine)
PATHOGEN: Dickeya dieffenbachiae
PATHOGEN SYNONYM: Erwinia chrysanthemi pv. dieffenbachiae
SOURCE: A. Alvarez
DISEASE: Bacterial stem rot
HOST: Dieffenbachia
Dieffenbachia with wilted and rotted leaves.
Bacterial stem rot | Dieffenbachia
DISEASE: Bacterial stem rot
HOST: Dieffenbachia (Dieffenbachia seguine)
PATHOGEN: Dickeya dieffenbachiae
PATHOGEN SYNONYM: Erwinia chrysanthemi pv. dieffenbachiae
SOURCE: R. Raabe
DISEASE: Bacterial stem rot
HOST: Dieffenbachia
Cross section of stem exposing rotted tissues.
Bacterial stem rot | Dieffenbachia
DISEASE: Bacterial stem rot
HOST: Dieffenbachia (Dieffenbachia seguine)
PATHOGEN: Dickeya dieffenbachiae
PATHOGEN SYNONYM: Erwinia chrysanthemi pv. dieffenbachiae
SOURCE: R. Raabe
DISEASE: Bacterial stem rot
HOST: Dieffenbachia
Leaf with rot and wilt.
Bacterial stem rot | Dieffenbachia
DISEASE: Bacterial stem rot
HOST: Dieffenbachia (Dieffenbachia seguine)
PATHOGEN: Dickeya dieffenbachiae
PATHOGEN SYNONYM: Erwinia chrysanthemi pv. dieffenbachiae
SOURCE: R. Raabe
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: Crown gall
HOST: Pear
Crown gall of pear rootstock.
Crown gall | Pear
DISEASE: Crown gall
HOST: Pear (Pyrus communis)
PATHOGEN: Agrobacterium tumefaciens
PATHOGEN SYNONYM: Rhizobium sp.
SOURCE: H. Sawada, M. Goto
DISEASE: Fire blight
HOST: Pear
Blighted shoot and blossoms.
Fire blight | Pear
DISEASE: Fire blight
HOST: Pear (Pyrus communis)
PATHOGEN: Erwinia amylovora
SOURCE: M. Schroth