DISEASE: Alfalfa dwarf
HOST: Alfalfa
Alfalfa dwarf is characterized by stunted plants (left), usually dark blue-green in color. Xylem tissues become brown, especially when exposed to air.
Alfalfa dwarf | Alfalfa
DISEASE: Alfalfa dwarf
HOST: Alfalfa (Medicago sativa)
PATHOGEN: Xylella fastidiosa
SOURCE: R. M. Davis
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: 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: Alfalfa
Stems with necrotic lesions.
Bacterial leaf spot | Alfalfa
DISEASE: Bacterial leaf spot
HOST: Alfalfa (Medicago sativa)
PATHOGEN: Xanthomonas alfalfae subsp. alfalfae
PATHOGEN SYNONYM: Xanthomonas campestris pv. alfalfae
SOURCE: APS
DISEASE: Bacterial leaf spot
HOST: Alfalfa
Leaves with brown necrotic spots. Stems have water-soaked spots.
Bacterial leaf spot | Alfalfa
DISEASE: Bacterial leaf spot
HOST: Alfalfa (Medicago sativa)
PATHOGEN: Xanthomonas alfalfae subsp. alfalfae
PATHOGEN SYNONYM: Xanthomonas campestris pv. alfalfae
SOURCE: S. Thomson