DISEASE: Bacterial blight
HOST: Tulip
The disease causes white veins of leaves, yellow vascular bundles, and yellow bacterial slime on bulbs.

Bacterial blight | Tulip
DISEASE: Bacterial blight
HOST: Tulip (Tulipa sp. 'Paul Richter')
PATHOGEN: Curtobacterium flaccumfaciens pv. oortii
PATHOGEN SYNONYM: Corynebacterium flaccumfaciens subsp. oortii
SOURCE: M. Geesteranus, J. van der Wolf
DISEASE: Bacterial blight
HOST: Tulip
Stunted plants with wrinkled leaves.

Bacterial blight | Tulip
DISEASE: Bacterial blight
HOST: Tulip (Tulipa sp. 'Paul Richter')
PATHOGEN: Curtobacterium flaccumfaciens pv. oortii
PATHOGEN SYNONYM: Corynebacterium flaccumfaciens subsp. oortii
SOURCE: M. Geesteranus, J. van der Wolf
DISEASE: Brittle root
HOST: Horseradish
Dying, stunted, yellow to brown horseradish plants.

Brittle root | Horseradish
DISEASE: Brittle root
HOST: Horseradish (Armoracia rusticana)
PATHOGEN: Spiroplasma citri
SOURCE: C. Eastman, M. Davis
DISEASE: Brittle root
HOST: Horseradish
Close-up of stunted, yellow horseradish plants.

Brittle root | Horseradish
DISEASE: Brittle root
HOST: Horseradish (Armoracia rusticana)
PATHOGEN: Spiroplasma citri
SOURCE: D. Sherrod
DISEASE: Brittle root
HOST: Horseradish
Horseradish with discolored internal tissues. Healthy root segment (top right).

Brittle root | Horseradish
DISEASE: Brittle root
HOST: Horseradish (Armoracia rusticana)
PATHOGEN: Spiroplasma citri
SOURCE: J. Fletcher, M. Davis
DISEASE: Bunch disease (Witches'-broom)
HOST: Butternut
Bunch disease of butternut.

Bunch disease (Witches'-broom) | Butternut
DISEASE: Bunch disease (Witches'-broom)
HOST: Butternut (Juglans cinerea)
PATHOGEN: 'Candidatus Phytoplasma pruni'
PATHOGEN SYNONYM: Phytoplasma X-disease group
SOURCE: W. Sinclair
DISEASE: Bunch disease
HOST: Pecan
Pecan exhibiting bunch symptoms at ends of branches. This disease is thought to be caused by a phytoplasma similar to the walnut bunch pathogen in the X-disease group.

Bunch disease | Pecan
DISEASE: Bunch disease
HOST: Pecan (Carya illinoinensis)
PATHOGEN: 'Candidatus Phytoplasma pruni'
PATHOGEN SYNONYM: Phytoplasma X-disease group
SOURCE: W. Sinclair
DISEASE: Bunch disease
HOST: Pecan
Severe case of bunch disease. Note bunches of foliage.

Bunch disease | Pecan
DISEASE: Bunch disease
HOST: Pecan (Carya illinoinensis)
PATHOGEN: 'Candidatus Phytoplasma pruni'
PATHOGEN SYNONYM: Phytoplasma X-disease group
SOURCE: P. Bertrand