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 blight
HOST: Lilac
Blighted twig with shriveled leaves and dark brown streaks on stem.

Bacterial blight | Lilac
DISEASE: Bacterial blight
HOST: Lilac (Syringa vulgaris)
PATHOGEN: Pseudomonas syringae pv. syringae
SOURCE: S. Thomson
DISEASE: Bacterial blight
HOST: Lilac
Lilac with blighted twigs.

Bacterial blight | Lilac
DISEASE: Bacterial blight
HOST: Lilac (Syringa vulgaris)
PATHOGEN: Pseudomonas syringae pv. syringae
SOURCE: W. Sinclair
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