DISEASE: Alfalfa dwarf
HOST: Alfalfa
Alfalfa dwarf is characterized by stunted plants (left), usually dark blue-green in color. Xylem tissues become brown, especially when exposed to air.

Alfalfa dwarf | Alfalfa
DISEASE: Alfalfa dwarf
HOST: Alfalfa (Medicago sativa)
PATHOGEN: Xylella fastidiosa
SOURCE: R. M. Davis
DISEASE: Brown line and decline
HOST: Almond
Stunted and yellowish diseased tree. Such trees produce little to no growth and decline rapidly.

Brown line and decline | Almond
DISEASE: Brown line and decline
HOST: Almond (Prunus dulcis)
PATHOGEN: 'Candidatus Phytoplasma' sp.
PATHOGEN SYNONYM: Phytoplasma (undefined)
SOURCE: B. Teviotdale
DISEASE: Brown line and decline
HOST: Almond
Bark was split laterally at graft union, revealing line of necrotic tissue that extends into woody cortical tissues.

Brown line and decline | Almond
DISEASE: Brown line and decline
HOST: Almond (Prunus dulcis)
PATHOGEN: 'Candidatus Phytoplasma' sp.
PATHOGEN SYNONYM: Phytoplasma (undefined)
SOURCE: J. Uyemoto
DISEASE: Brown line and decline
HOST: Almond
Shriveled nuts from infected tree. Two healthy kernels (bottom left).

Brown line and decline | Almond
DISEASE: Brown line and decline
HOST: Almond (Prunus dulcis)
PATHOGEN: 'Candidatus Phytoplasma' sp.
PATHOGEN SYNONYM: Phytoplasma (undefined)
SOURCE: J. Uyemoto
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