DISEASE: Apple proliferation
HOST: Apple
Enlarged stipules on leaf. Witches'-brooms, rosettes, and enlarged stipules are the most reliable symptoms for identification.

Apple proliferation | Apple
DISEASE: Apple proliferation
HOST: Apple (Malus domestica 'Granny Smith')
PATHOGEN: 'Candidatus Phytoplasma mali'
PATHOGEN SYNONYM: Phytoplasma Apple proliferation group
SOURCE: M. Wolf, W. Schweigkofler
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 wilt
HOST: Grass
Initial symptom is a lime-green, yellow, or blue-green appearance of the grass. The next symptom is small, reddish brown spots on leaf blades.

Bacterial wilt | Grass
DISEASE: Bacterial wilt
HOST: Grass (Poa annua)
PATHOGEN: Xanthomonas translucens pv. poae
SOURCE: P. H. Dernoeden
DISEASE: Bacterial wilt
HOST: Grass
Infected turf grass with patches of yellowing, wilted, and dead grass.

Bacterial wilt | Grass
DISEASE: Bacterial wilt
HOST: Grass (Poa annua)
PATHOGEN: Xanthomonas translucens pv. poae
SOURCE: APS