DISEASE: Aster yellows
HOST: Watercress
Diseased watercress (left) and healthy plant (right).

Aster yellows | Watercress
DISEASE: Aster yellows
HOST: Watercress (Nasturtium officinale)
PATHOGEN: 'Candidatus Phytoplasma asteris'
PATHOGEN SYNONYM: Phytoplasma Aster yellows group
SOURCE: W. Borth
DISEASE: Aster yellows
HOST: Wheat
Healthy head (left) and diseased head (right). Diseased seedlings may die within 2 to 3 weeks. Infected heads of surviving plants are small and sterile, with distorted awns.

Aster yellows | Wheat
DISEASE: Aster yellows
HOST: Wheat (Triticum aestivum)
PATHOGEN: 'Candidatus Phytoplasma asteris'
PATHOGEN SYNONYM: Phytoplasma Aster yellows group
SOURCE: L. N. Chiykowski
DISEASE: Aster yellows
HOST: Zinnia
Yellowing and shoot proliferation of foliage.

Aster yellows | Zinnia
DISEASE: Aster yellows
HOST: Zinnia (Zinnia violacea)
PATHOGEN: 'Candidatus Phytoplasma asteris'
PATHOGEN SYNONYM: Phytoplasma Aster yellows group
SOURCE: J. Forsberg, M. Shurtleff
DISEASE: Bacterial wilt
HOST: Bean
Bean leaf with white pustules following inoculation. Stem inoculation causes veinal yellowing and necrosis of leaves. Infected seed may be purple or yellow.

Bacterial wilt | Bean
DISEASE: Bacterial wilt
HOST: Bean (Phaseolus vulgaris)
PATHOGEN: Curtobacterium flaccumfaciens pv. flaccumfaciens
SOURCE: L. Claflin
DISEASE: Bacterial wilt
HOST: Bean
Leaves with interveinal chlorosis and necrosis. Healthy (right).

Bacterial wilt | Bean
DISEASE: Bacterial wilt
HOST: Bean (Phaseolus vulgaris)
PATHOGEN: Curtobacterium flaccumfaciens pv. flaccumfaciens
SOURCE: APS
DISEASE: Bacterial wilt
HOST: Bean
Bean seeds infected with orange (upper right), violet (upper left), and yellow (lower left) variants of Curtobacterium flaccumfaciens. White seed in the lower right is healthy.

Bacterial wilt | Bean
DISEASE: Bacterial wilt
HOST: Bean (Phaseolus vulgaris)
PATHOGEN: Curtobacterium flaccumfaciens pv. flaccumfaciens
SOURCE: APS
DISEASE: Bacterial wilt
HOST: Bean
Common bean with brownish purple discoloration of hypocotyl caused by infection from infested seed.

Bacterial wilt | Bean
DISEASE: Bacterial wilt
HOST: Bean (Phaseolus vulgaris)
PATHOGEN: Curtobacterium flaccumfaciens pv. flaccumfaciens
SOURCE: APS
DISEASE: Bacterial wilt
HOST: Bean
Dry bean with discoloration between veins and veinlets.

Bacterial wilt | Bean
DISEASE: Bacterial wilt
HOST: Bean (Phaseolus vulgaris)
PATHOGEN: Curtobacterium flaccumfaciens pv. flaccumfaciens
SOURCE: H. Schwartz