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 blight
HOST: Spathiphyllum
Progression of disease severity on leaves from right to left.
Bacterial blight | Spathiphyllum
DISEASE: Bacterial blight
HOST: Spathiphyllum (Spathiphyllum sp.)
PATHOGEN: Xanthomonas axonopodis pv. dieffenbachiae
PATHOGEN SYNONYM: Xanthomonas campestris pv. dieffenbachiae
SOURCE: A. Alvarez
DISEASE: Bacterial gall
HOST: Carrot
Root with many galls of different sizes.
Bacterial gall | Carrot
DISEASE: Bacterial gall
HOST: Carrot (Daucus carota)
PATHOGEN: Rhizobacter dauci
SOURCE: H. Kuwata
DISEASE: Bacterial gall
HOST: Carrot
Galls caused from inoculation of injured roots (left two) and uninjured roots (center two). Uninjured, noninoculated root (right).
Bacterial gall | Carrot
DISEASE: Bacterial gall
HOST: Carrot (Daucus carota)
PATHOGEN: Rhizobacter dauci
SOURCE: M. Goto
DISEASE: Bacterial leaf blight
HOST: Carrot
Blight of flower parts.
Bacterial leaf blight | Carrot
DISEASE: Bacterial leaf blight
HOST: Carrot (Daucus carota)
PATHOGEN: Xanthomonas hortorum pv. carotae
PATHOGEN SYNONYM: Xanthomonas campestris pv. carotae
SOURCE: N. Schaad
DISEASE: Bacterial leaf blight
HOST: Carrot
Leaf lesions begin as water-soaked spots that progress to small, yellow, angular spots and later expand to necrotic lesions with yellow halos.
Bacterial leaf blight | Carrot
DISEASE: Bacterial leaf blight
HOST: Carrot (Daucus carota)
PATHOGEN: Xanthomonas hortorum pv. carotae
PATHOGEN SYNONYM: Xanthomonas campestris pv. carotae
SOURCE: N. Schaad
DISEASE: Bacterial leaf blight
HOST: Carrot
Bacterial ooze on flower stalk from systemic invasion of the pathogen.
Bacterial leaf blight | Carrot
DISEASE: Bacterial leaf blight
HOST: Carrot (Daucus carota)
PATHOGEN: Xanthomonas hortorum pv. carotae
PATHOGEN SYNONYM: Xanthomonas campestris pv. carotae
SOURCE: APS
DISEASE: Bacterial soft rot
HOST: Carrot
Carrots with advanced stage of soft rot. Lesions on taproots are sunken and dull orange. The epidermis may stay intact in early stages of disease.
Bacterial soft rot | Carrot
DISEASE: Bacterial soft rot
HOST: Carrot (Daucus carota)
PATHOGEN: Dickeya sp.
PATHOGEN SYNONYM: Erwinia chrysanthemi
SOURCE: APS
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