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 soft rot
HOST: Wasabi (Japanese horseradish)
Longitudinal sections of diseased rhizomes with discolored vascular tissues.

Bacterial soft rot | Wasabi (Japanese horseradish)
DISEASE: Bacterial soft rot
HOST: Wasabi (Japanese horseradish) (Wasabia japonica)
PATHOGEN: Pectobacterium wasabiae
PATHOGEN SYNONYM: Erwinia carotovora subsp. wasabiae
SOURCE: M. Goto
DISEASE: Bacterial soft rot
HOST: Wasabi (Japanese horseradish)
Longitudinal section of rhizome with discolored vascular bundles (left), and rhizome with external symptoms (right).

Bacterial soft rot | Wasabi (Japanese horseradish)
DISEASE: Bacterial soft rot
HOST: Wasabi (Japanese horseradish) (Wasabia japonica)
PATHOGEN: Pectobacterium wasabiae
PATHOGEN SYNONYM: Erwinia carotovora subsp. wasabiae
SOURCE: M. Goto
DISEASE: Bacterial soft rot
HOST: Wasabi (Japanese horseradish)
Cross section of rhizome with dark, infected vascular bundles.

Bacterial soft rot | Wasabi (Japanese horseradish)
DISEASE: Bacterial soft rot
HOST: Wasabi (Japanese horseradish) (Wasabia japonica)
PATHOGEN: Pectobacterium wasabiae
PATHOGEN SYNONYM: Erwinia carotovora subsp. wasabiae
SOURCE: G. Rodriguez
DISEASE: Halo blight
HOST: Bean
Leaf of 'Bountiful' bean with chlorotic halos, an early stage of disease. Tiny water-soaked are difficult to see.

Halo blight | Bean
DISEASE: Halo blight
HOST: Bean (Phaseolus vulgaris 'Bountiful')
PATHOGEN: Pseudomonas syringae pv. phaseolicola
PATHOGEN SYNONYM: Pseudomonas savastanoi pv. phaseolicola
SOURCE: M. Schroth