DISEASE: Bacterial leaf spot
HOST: Nephthytis
Leaf with concentric rings of dark tissues. There has been confusion of the causal agent with Dickeya sp., which also causes mushy leaf spots.
Bacterial leaf spot | Nephthytis
DISEASE: Bacterial leaf spot
HOST: Nephthytis (Syngonium podophyllum)
PATHOGEN: Pectobacterium carotovorum
PATHOGEN SYNONYM: Erwinia carotovora subsp. carotovora
SOURCE: A. Chase
DISEASE: Bacterial leaf spot
HOST: Nephthytis
Water-soaked tissues and large, dark brown necrotic areas at leaf margins. Healthy (center leaf).
Bacterial leaf spot | Nephthytis
DISEASE: Bacterial leaf spot
HOST: Nephthytis (Syngonium podophyllum)
PATHOGEN: Pseudomonas cichorii
SOURCE: S. Thomson
DISEASE: Bois noir disease
HOST: Grape
Bois noir disease may be expressed on one branch while other branches appear healthy. Note trapezoid-shaped leaves.
Bois noir disease | Grape
DISEASE: Bois noir disease
HOST: Grape (Vitis vinifera 'Chardonnay')
PATHOGEN: 'Candidatus Phytoplasma solani'
PATHOGEN SYNONYM: Phytoplasma Stolbur group
SOURCE: W. Schweigkofler
DISEASE: Bois noir disease
HOST: Grape
Typical symptoms of triangular-trapezoid-shaped, greenish yellow leaves.
Bois noir disease | Grape
DISEASE: Bois noir disease
HOST: Grape (Vitis vinifera 'Chardonnay')
PATHOGEN: 'Candidatus Phytoplasma solani'
PATHOGEN SYNONYM: Phytoplasma Stolbur group
SOURCE: W. Schweigkofler
DISEASE: Bois noir disease
HOST: Grape
Berries from infected vines are shrunken and low in sugar and have a high acid content, making them unfit for wine production.
Bois noir disease | Grape
DISEASE: Bois noir disease
HOST: Grape (Vitis vinifera 'Chardonnay')
PATHOGEN: 'Candidatus Phytoplasma solani'
PATHOGEN SYNONYM: Phytoplasma Stolbur group
SOURCE: W. Schweigkofler
DISEASE: Bois noir disease
HOST: Grape
A typical symptom of disease is uneven lignification of infected branches, resulting in a mix of brown and green patches.
Bois noir disease | Grape
DISEASE: Bois noir disease
HOST: Grape (Vitis vinifera 'Chardonnay')
PATHOGEN: 'Candidatus Phytoplasma solani'
PATHOGEN SYNONYM: Phytoplasma Stolbur group
SOURCE: W. Schweigkofler
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