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: 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 leaf spot
HOST: Nephthytis
Leaf with concentric rings of dark tissues. There has been confusion of the causal agent with Dickeya sp., which also causes mushy leaf spots.

Bacterial leaf spot | Nephthytis
DISEASE: Bacterial leaf spot
HOST: Nephthytis (Syngonium podophyllum)
PATHOGEN: Pectobacterium carotovorum
PATHOGEN SYNONYM: Erwinia carotovora subsp. carotovora
SOURCE: A. Chase
DISEASE: Bacterial leaf spot
HOST: Nephthytis
Water-soaked tissues and large, dark brown necrotic areas at leaf margins. Healthy (center leaf).

Bacterial leaf spot | Nephthytis
DISEASE: Bacterial leaf spot
HOST: Nephthytis (Syngonium podophyllum)
PATHOGEN: Pseudomonas cichorii
SOURCE: S. Thomson
DISEASE: Bacterial leaf spot
HOST: Zinnia
Leaf with small, brown spots.

Bacterial leaf spot | Zinnia
DISEASE: Bacterial leaf spot
HOST: Zinnia (Zinnia violacea)
PATHOGEN: Xanthomonas campestris pv. zinniae
SOURCE: M. Goto
DISEASE: Bacterial leaf spot
HOST: Zinnia
Leaf with blackish, necrotic, angular spots.

Bacterial leaf spot | Zinnia
DISEASE: Bacterial leaf spot
HOST: Zinnia (Zinnia violacea)
PATHOGEN: Xanthomonas campestris pv. zinniae
SOURCE: M. Daughtrey
DISEASE: Syngonium blight
HOST: Nephthytis
Leaf with large, brown to blackish necrotic areas.

Syngonium blight | Nephthytis
DISEASE: Syngonium blight
HOST: Nephthytis (Syngonium podophyllum)
PATHOGEN: Xanthomonas axonopodis pv. dieffenbachiae
PATHOGEN SYNONYM: Xanthomonas campestris pv. dieffenbachiae
SOURCE: R. Raabe