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: Brown line and decline
HOST: Almond
Stunted and yellowish diseased tree. Such trees produce little to no growth and decline rapidly.
Brown line and decline | Almond
DISEASE: Brown line and decline
HOST: Almond (Prunus dulcis)
PATHOGEN: 'Candidatus Phytoplasma' sp.
PATHOGEN SYNONYM: Phytoplasma (undefined)
SOURCE: B. Teviotdale
DISEASE: Brown line and decline
HOST: Almond
Bark was split laterally at graft union, revealing line of necrotic tissue that extends into woody cortical tissues.
Brown line and decline | Almond
DISEASE: Brown line and decline
HOST: Almond (Prunus dulcis)
PATHOGEN: 'Candidatus Phytoplasma' sp.
PATHOGEN SYNONYM: Phytoplasma (undefined)
SOURCE: J. Uyemoto
DISEASE: Brown line and decline
HOST: Almond
Shriveled nuts from infected tree. Two healthy kernels (bottom left).
Brown line and decline | Almond
DISEASE: Brown line and decline
HOST: Almond (Prunus dulcis)
PATHOGEN: 'Candidatus Phytoplasma' sp.
PATHOGEN SYNONYM: Phytoplasma (undefined)
SOURCE: J. Uyemoto
DISEASE: Drippy nut disease
HOST: Oak
Ooze from young twig inoculated with Brenneria quercina.
Drippy nut disease | Oak
DISEASE: Drippy nut disease
HOST: Oak (Quercus agrifolia)
PATHOGEN: Brenneria quercina
PATHOGEN SYNONYM: Erwinia quercina
SOURCE: M. Schroth
DISEASE: Drippy nut disease
HOST: Oak
Ooze from infected acorn. Copious ooze drips from infected acorns, leaving sticky spots on objects under tree canopy. Infections are associated with insect oviposit wounds.
Drippy nut disease | Oak
DISEASE: Drippy nut disease
HOST: Oak (Quercus agrifolia)
PATHOGEN: Brenneria quercina
PATHOGEN SYNONYM: Erwinia quercina
SOURCE: M. Schroth