DISEASE: Alfalfa dwarf
HOST: Alfalfa
Alfalfa dwarf is characterized by stunted plants (left), usually dark blue-green in color. Xylem tissues become brown, especially when exposed to air.

Alfalfa dwarf | Alfalfa
DISEASE: Alfalfa dwarf
HOST: Alfalfa (Medicago sativa)
PATHOGEN: Xylella fastidiosa
SOURCE: R. M. Davis
DISEASE: Bacterial stem and rhizome rot
HOST: Iris
Iris stem and rhizome with brown, discolored, rotted portions.

Bacterial stem and rhizome rot | Iris
DISEASE: Bacterial stem and rhizome rot
HOST: Iris (Iris sp.)
PATHOGEN: Burkholderia gladioli pv. gladioli
PATHOGEN SYNONYM: Pseudomonas gladioli pv. gladioli
SOURCE: R. Raabe
DISEASE: Bacterial stem and rhizome rot
HOST: Iris
Mushy rot of stems and rhizomes are characteristic of advanced stage of the disease.

Bacterial stem and rhizome rot | Iris
DISEASE: Bacterial stem and rhizome rot
HOST: Iris (Iris sp.)
PATHOGEN: Burkholderia gladioli pv. gladioli
PATHOGEN SYNONYM: Pseudomonas gladioli pv. gladioli
SOURCE: R. Raabe
DISEASE: Periwinkle yellows
HOST: Periwinkle
Leaves with characteristic yellow and chlorotic appearance. Yellowing is first associated with veins.

Periwinkle yellows | Periwinkle
DISEASE: Periwinkle yellows
HOST: Periwinkle (Vinca sp.)
PATHOGEN: 'Candidatus Phytoplasma' sp.
PATHOGEN SYNONYM: Phytoplasma (undefined)
SOURCE: R. McCoy, M. Davis