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: Gumming disease
HOST: Sugarcane
Symptoms include brownish red streaks on leaves with apical chlorosis. Streaks become necrotic with time. Plants are stunted with reddening of vascular bundles.

Gumming disease | Sugarcane
DISEASE: Gumming disease
HOST: Sugarcane (Saccharum officinarum)
PATHOGEN: Xanthomonas axonopodis pv. vasculorum
PATHOGEN SYNONYM: Xanthomonas campestris pv. vasculorum
SOURCE: APS
DISEASE: Olive knot
HOST: Olive
Multiple infections of young stems. The bacterium invades vascular tissues during certain times of the year and may be isolated from branches that appear healthy.

Olive knot | Olive
DISEASE: Olive knot
HOST: Olive (Olea europaea)
PATHOGEN: Pseudomonas savastanoi pv. savastanoi
SOURCE: M. Schroth
DISEASE: Olive knot
HOST: Olive
Tree with knots/galls on branches along with twig dieback, which is associated with knots. Fusarium and Diplodia spp. infect through knots and are thought to be main reason for dieback.

Olive knot | Olive
DISEASE: Olive knot
HOST: Olive (Olea europaea)
PATHOGEN: Pseudomonas savastanoi pv. savastanoi
SOURCE: M. Schroth