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 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 leaf spot
HOST: Schefflera
Leaf with water-soaked lesions.

Bacterial leaf spot | Schefflera
DISEASE: Bacterial leaf spot
HOST: Schefflera (Schefflera actinophylla)
PATHOGEN: Xanthomonas hortorum pv. hederae
PATHOGEN SYNONYM: Xanthomonas campestris pv. hederae
SOURCE: M. Gleason
DISEASE: Bacterial leaf spot
HOST: Schefflera
Leaf with large, grayish necrotic areas.

Bacterial leaf spot | Schefflera
DISEASE: Bacterial leaf spot
HOST: Schefflera (Schefflera actinophylla)
PATHOGEN: Xanthomonas hortorum pv. hederae
PATHOGEN SYNONYM: Xanthomonas campestris pv. hederae
SOURCE: A. Chase
DISEASE: Bacterial leaf spot
HOST: Schefflera
Leaf with many small, pinpoint-sized lesions and a few large lesions.

Bacterial leaf spot | Schefflera
DISEASE: Bacterial leaf spot
HOST: Schefflera (Schefflera arboricola)
PATHOGEN: Xanthomonas hortorum pv. hederae
PATHOGEN SYNONYM: Xanthomonas campestris pv. hederae
SOURCE: A. Chase