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: Papaya dieback
HOST: Papaya
Dieback is characterized by terminal necrosis and death of the young and old plants.

Papaya dieback | Papaya
DISEASE: Papaya dieback
HOST: Papaya (Carica papaya)
PATHOGEN: 'Candidatus Phytoplasma australiense'
PATHOGEN SYNONYM: Phytoplasma Stolbur group
SOURCE: D. Teakle
DISEASE: Papaya dieback
HOST: Papaya
Death of growing point, a symptom of the disease.

Papaya dieback | Papaya
DISEASE: Papaya dieback
HOST: Papaya (Carica papaya)
PATHOGEN: 'Candidatus Phytoplasma australiense'
PATHOGEN SYNONYM: Phytoplasma Stolbur group
SOURCE: D. Teakle
DISEASE: Sour skin
HOST: Onion
Symptoms of sour skin are characterized by slimy, pale yellow to light brown decay.

Sour skin | Onion
DISEASE: Sour skin
HOST: Onion (Allium cepa)
PATHOGEN: Burkholderia cepacia
PATHOGEN SYNONYM: Pseudomonas cepacia
SOURCE: Dep. of Agric. & Agri-Food, Government of Canada