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: Citrus stubborn disease
HOST: Citrus (sp. unknown)
Characteristic symptoms of thickened peel at peduncle end and aborted seeds.
Citrus stubborn disease | Citrus (sp. unknown)
DISEASE: Citrus stubborn disease
HOST: Citrus (sp. unknown) (Citrus sp.)
PATHOGEN: Spiroplasma citri
SOURCE: APS
DISEASE: Citrus stubborn disease
HOST: Citrus (Orange)
Severely stunted sweet orange tree. Foliage is dense and abnormally upright. Leaves may be cupped and unusually thick. They also may be chlorotic and mottled.
Citrus stubborn disease | Citrus (Orange)
DISEASE: Citrus stubborn disease
HOST: Citrus (Orange) (Citrus sinensis)
PATHOGEN: Spiroplasma citri
SOURCE: S. M. Garnsey
DISEASE: Citrus stubborn disease
HOST: Citrus (Orange)
Fruit from a diseased tree are frequently lopsided or acorn-shaped, usually few and small. They may not color at stem end.
Citrus stubborn disease | Citrus (Orange)
DISEASE: Citrus stubborn disease
HOST: Citrus (Orange) (Citrus sinensis)
PATHOGEN: Spiroplasma citri
SOURCE: J. M. Bove, M. Garnier
DISEASE: Citrus stubborn disease
HOST: Citrus (Orange)
Sweet orange exhibiting off-season flowering and crop heterogeneity. Diseased trees generally have shoots with shortened internodes, which lead to rosettes with cupped leaves.
Citrus stubborn disease | Citrus (Orange)
DISEASE: Citrus stubborn disease
HOST: Citrus (Orange) (Citrus sinensis)
PATHOGEN: Spiroplasma citri
SOURCE: J. M. Bove, M. Garnier
DISEASE: Ear rot
HOST: Corn (Maize)
Rot at apical end of ear.
Ear rot | Corn (Maize)
DISEASE: Ear rot
HOST: Corn (Maize) (Zea mays)
PATHOGEN: Pseudomonas marginalis
SOURCE: L. Fucikovsky
DISEASE: Marginal leaf blight
HOST: Lettuce
Marginal leaf blight first appears as slimy wilting of leaf margins. Small, reddish lesions may be seen on leaf blades. Infected tissues turn brown to black in time.
Marginal leaf blight | Lettuce
DISEASE: Marginal leaf blight
HOST: Lettuce (Lactuca sativa)
PATHOGEN: Pseudomonas marginalis
SOURCE: L. Fucikovsky