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 blight and rot
HOST: Orchid
Leaves of Dendrobium orchid with necrosis, discoloration, and rot.

Bacterial leaf blight and rot | Orchid
DISEASE: Bacterial leaf blight and rot
HOST: Orchid (Dendrobium sp.)
PATHOGEN: Burkholderia gladioli pv. gladioli
PATHOGEN SYNONYM: Pseudomonas gladioli pv. gladioli
SOURCE: L. Keith
DISEASE: Elm yellows
HOST: Elm
Elm yellows is characterized by witches'-brooms and stunting. Some cultivars have both yellow and reddish foliar discoloration.

Elm yellows | Elm
DISEASE: Elm yellows
HOST: Elm (Ulmus parvifolia)
PATHOGEN: 'Candidatus Phytoplasma ulmi'
PATHOGEN SYNONYM: Phytoplasma Elm yellows group
SOURCE: W. Sinclair