DISEASE: Australian citrus dieback
HOST: Citrus (Lime)
Severe decline, a late stage of disease. The disease spreads slowly in mature trees, progressing faster in young trees.

Australian citrus dieback | Citrus (Lime)
DISEASE: Australian citrus dieback
HOST: Citrus (Lime) (Citrus sp.)
PATHOGEN: 'Candidatus Phytoplasma australiense'
PATHOGEN SYNONYM: Phytoplasma Stolbur group
SOURCE: P. Broadbent
DISEASE: Bacterial blast and black pit
HOST: Citrus (Lime)
Characteristic symptoms of brownish black lesions on twigs and leaves (blast), starting with infection of petioles. Black pit refers to brown to black sunken spots on fruit, 5 to 20 mm in diameter.

Bacterial blast and black pit | Citrus (Lime)
DISEASE: Bacterial blast and black pit
HOST: Citrus (Lime) (Citrus sp.)
PATHOGEN: Pseudomonas syringae pv. syringae
SOURCE: P. Broadbent
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: 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
DISEASE: Oak leaf scorch
HOST: Oak
Oak with scorched leaf tips.

Oak leaf scorch | Oak
DISEASE: Oak leaf scorch
HOST: Oak (Quercus kelloggii)
PATHOGEN: Xylella fastidiosa
SOURCE: S. Kostka