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: Brittle root
HOST: Horseradish
Dying, stunted, yellow to brown horseradish plants.

Brittle root | Horseradish
DISEASE: Brittle root
HOST: Horseradish (Armoracia rusticana)
PATHOGEN: Spiroplasma citri
SOURCE: C. Eastman, M. Davis
DISEASE: Brittle root
HOST: Horseradish
Close-up of stunted, yellow horseradish plants.

Brittle root | Horseradish
DISEASE: Brittle root
HOST: Horseradish (Armoracia rusticana)
PATHOGEN: Spiroplasma citri
SOURCE: D. Sherrod
DISEASE: Brittle root
HOST: Horseradish
Horseradish with discolored internal tissues. Healthy root segment (top right).

Brittle root | Horseradish
DISEASE: Brittle root
HOST: Horseradish (Armoracia rusticana)
PATHOGEN: Spiroplasma citri
SOURCE: J. Fletcher, M. Davis
DISEASE: Shallow bark canker
HOST: Walnut
Diseased, discolored tissues revealed by removing external bark.

Shallow bark canker | Walnut
DISEASE: Shallow bark canker
HOST: Walnut (Juglans regia 'Hartley')
PATHOGEN: Brenneria nigrifluens
PATHOGEN SYNONYM: Erwinia nigrifluens
SOURCE: B. Teviotdale
DISEASE: Shallow bark canker
HOST: Walnut
Trunk with brown exudate shallow cankers.

Shallow bark canker | Walnut
DISEASE: Shallow bark canker
HOST: Walnut (Juglans regia 'Hartley')
PATHOGEN: Brenneria nigrifluens
PATHOGEN SYNONYM: Erwinia nigrifluens
SOURCE: B. Teviotdale