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 leaf spot (Head rot)
HOST: Cauliflower
Leaves with tiny lesions surrounded by large halos.

Bacterial leaf spot (Head rot) | Cauliflower
DISEASE: Bacterial leaf spot (Head rot)
HOST: Cauliflower (Brassica oleracea var. botrytis)
PATHOGEN: Pseudomonas syringae pv. maculicola
SOURCE: R. Campbell
DISEASE: Bacterial leaf spot (Head rot)
HOST: Cauliflower
Section of a cauliflower head with discolored, infected tissues.

Bacterial leaf spot (Head rot) | Cauliflower
DISEASE: Bacterial leaf spot (Head rot)
HOST: Cauliflower (Brassica oleracea var. botrytis)
PATHOGEN: Pseudomonas syringae pv. maculicola
SOURCE: R. Campbell
DISEASE: Bacterial wilt
HOST: Heliconia
Wilted and dying heliconia plant.

Bacterial wilt | Heliconia
DISEASE: Bacterial wilt
HOST: Heliconia (Heliconia sp.)
PATHOGEN: Ralstonia solanacearum
PATHOGEN SYNONYM: Pseudomonas solanacearum
SOURCE: I. Buddenhagen
DISEASE: Bacterial wilt
HOST: Heliconia
Heliconia spathes with wilt and leaf necrosis.

Bacterial wilt | Heliconia
DISEASE: Bacterial wilt
HOST: Heliconia (Heliconia sp.)
PATHOGEN: Ralstonia solanacearum
PATHOGEN SYNONYM: Pseudomonas solanacearum
SOURCE: I. Buddenhagen
DISEASE: Bacterial wilt
HOST: Heliconia
Heliconia stalk with discolored base.

Bacterial wilt | Heliconia
DISEASE: Bacterial wilt
HOST: Heliconia (Heliconia sp.)
PATHOGEN: Ralstonia solanacearum
PATHOGEN SYNONYM: Pseudomonas solanacearum
SOURCE: I. Buddenhagen
DISEASE: Bacterial wilt
HOST: Heliconia
Spathe of heliconia infected with bacterial wilt (right) compared with healthy spathe.

Bacterial wilt | Heliconia
DISEASE: Bacterial wilt
HOST: Heliconia (Heliconia sp.)
PATHOGEN: Ralstonia solanacearum
PATHOGEN SYNONYM: Pseudomonas solanacearum
SOURCE: I. Buddenhagen
DISEASE: Bacterial wilt
HOST: Squash
Field with severe symptoms of wilt. Foliage often is chlorotic and leaf margins may be chlorotic and necrotic before plant death. Bacterial ooze may be seen streaming from the xylem when infected stems are cut.

Bacterial wilt | Squash
DISEASE: Bacterial wilt
HOST: Squash (Cucurbita maxima)
PATHOGEN: Erwinia tracheiphila
SOURCE: B. Jacobsen, M. Shurtleff
DISEASE: Black rot
HOST: Cauliflower
Brown, necrotic, rotted areas on flower parts and typical V-shaped necrotic areas on leaf margins.

Black rot | Cauliflower
DISEASE: Black rot
HOST: Cauliflower (Brassica oleracea var. botrytis)
PATHOGEN: Xanthomonas campestris pv. campestris
SOURCE: B. Jacobsen, M. Shurtleff