DISEASE: Bacterial blight
HOST: Hazelnut
Diseased young tree with discoloration of the cambium. Dieback of young twigs and branches is characteristic. Other typical symptoms are bud and twig necrosis and small, angular or round, water-soaked leaf spots.

Bacterial blight | Hazelnut
DISEASE: Bacterial blight
HOST: Hazelnut (Corylus americana)
PATHOGEN: Xanthomonas arboricola pv. corylina
SOURCE: J. Pscheidt
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 greening (Huanglongbing)
HOST: Citrus (sp. unknown)
Citrus psyllid (Diaphorina citri), a vector of 'Candidatus Liberibacter asiaticus', the cause of citrus greening, feeding on green twig.

Citrus greening (Huanglongbing) | Citrus (sp. unknown)
DISEASE: Citrus greening (Huanglongbing)
HOST: Citrus (sp. unknown) (Citrus sp.)
PATHOGEN: 'Candidatus Liberibacter asiaticus'
PATHOGEN SYNONYM: Candidatus Liberobacter asiaticus
SOURCE: C. Jacobson
DISEASE: Citrus greening (Huanglongbing)
HOST: Citrus (sp. unknown)
Citrus psyllid (Diaphorina citri), a vector of 'Candidatus Liberibacter asiaticus', the cause of citrus greening.

Citrus greening (Huanglongbing) | Citrus (sp. unknown)
DISEASE: Citrus greening (Huanglongbing)
HOST: Citrus (sp. unknown) (Citrus sp.)
PATHOGEN: 'Candidatus Liberibacter asiaticus'
PATHOGEN SYNONYM: Candidatus Liberobacter asiaticus
SOURCE: C. Jacobson
DISEASE: Citrus greening (Huanglongbing)
HOST: Citrus (sp. unknown)
Citrus psyllid (Diaphorina citri), a vector of 'Candidatus Liberibacter asiaticus', the cause of citrus greening.

Citrus greening (Huanglongbing) | Citrus (sp. unknown)
DISEASE: Citrus greening (Huanglongbing)
HOST: Citrus (sp. unknown) (Citrus sp.)
PATHOGEN: 'Candidatus Liberibacter asiaticus'
PATHOGEN SYNONYM: Candidatus Liberobacter asiaticus
SOURCE: C. Hirayama
DISEASE: Citrus greening (Huanglongbing)
HOST: Citrus (Orange)
Mature infected fruit may be misshapen and vary in degree of greening.

Citrus greening (Huanglongbing) | Citrus (Orange)
DISEASE: Citrus greening (Huanglongbing)
HOST: Citrus (Orange) (Citrus sinensis)
PATHOGEN: 'Candidatus Liberibacter asiaticus'
PATHOGEN SYNONYM: Candidatus Liberobacter asiaticus
SOURCE: R. McCoy, M. Davis
DISEASE: Citrus greening (Huanglongbing)
HOST: Citrus (Orange)
Leaves with yellowish mottle resembling nutrient deficiency.

Citrus greening (Huanglongbing) | Citrus (Orange)
DISEASE: Citrus greening (Huanglongbing)
HOST: Citrus (Orange) (Citrus sinensis)
PATHOGEN: 'Candidatus Liberibacter asiaticus'
PATHOGEN SYNONYM: Candidatus Liberobacter asiaticus
SOURCE: D. Gabriel