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: Ratoon stunt
HOST: Sugarcane
Row of disease 'Trojan' plants (left). Healthy row (right).

Ratoon stunt | Sugarcane
DISEASE: Ratoon stunt
HOST: Sugarcane (Saccharum officinarum 'Trojan')
PATHOGEN: Leifsonia xyli subsp. xyli
SOURCE: D. Teakle
DISEASE: Witches'-broom
HOST: Paulownia (Empress tree)
Witches'-broom of paulownia.

Witches'-broom | Paulownia (Empress tree)
DISEASE: Witches'-broom
HOST: Paulownia (Empress tree) (Paulownia tomentosa)
PATHOGEN: 'Candidatus Phytoplasma' sp.
PATHOGEN SYNONYM: Phytoplasma (undefined)
SOURCE: R. Davis, M. Davis