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: 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: Bacterial wilt and dieback
HOST: Willow
Cross sections of the characteristic "watermark stain" of diseased wood. Wilt and dieback occur as disease progresses.

Bacterial wilt and dieback | Willow
DISEASE: Bacterial wilt and dieback
HOST: Willow (Salix sp.)
PATHOGEN: Brenneria salicis
PATHOGEN SYNONYM: Erwinia salicis
SOURCE: Y. Sakamoto, M. Goto
DISEASE: Bacterial wilt and dieback
HOST: Willow
Severely diseased tree with dieback symptoms.

Bacterial wilt and dieback | Willow
DISEASE: Bacterial wilt and dieback
HOST: Willow (Salix sp.)
PATHOGEN: Brenneria salicis
PATHOGEN SYNONYM: Erwinia salicis
SOURCE: Y. Sakamoto, M. Goto
DISEASE: Slime flux
HOST: Willow
Foam at site of infection. Slime fluxes are common but the causal agent has not been identified.

Slime flux | Willow
DISEASE: Slime flux
HOST: Willow (Salix sp.)
PATHOGEN: Causal agent unknown
SOURCE: S. Thomson