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: Bacterial seed and seedling rot
HOST: Geranium
Cotyledons with water-soaked spots.

Bacterial seed and seedling rot | Geranium
DISEASE: Bacterial seed and seedling rot
HOST: Geranium (Pelargonium sp.)
PATHOGEN: Paenibacillus sp.
SOURCE: A. Magyarosy, D. Thomas
DISEASE: Bacterial seed and seedling rot
HOST: Geranium
Rotted and discolored seeds (right). Healthy seeds (left).

Bacterial seed and seedling rot | Geranium
DISEASE: Bacterial seed and seedling rot
HOST: Geranium (Pelargonium sp.)
PATHOGEN: Paenibacillus sp.
SOURCE: A. Magyarosy, D. Thomas
DISEASE: Citrus variegated chlorosis
HOST: Citrus (sp. unknown)
Leaf with chlorosis in interveinal spaces and brown spots visible on lower leaf surface.

Citrus variegated chlorosis | Citrus (sp. unknown)
DISEASE: Citrus variegated chlorosis
HOST: Citrus (sp. unknown) (Citrus sp.)
PATHOGEN: Xylella fastidiosa
SOURCE: M. J. G. Beretta
DISEASE: Citrus variegated chlorosis
HOST: Citrus (sp. unknown)
Interveinal chlorosis on upper side of leaves.

Citrus variegated chlorosis | Citrus (sp. unknown)
DISEASE: Citrus variegated chlorosis
HOST: Citrus (sp. unknown) (Citrus sp.)
PATHOGEN: Xylella fastidiosa
SOURCE: M. J. G. Beretta
DISEASE: Citrus variegated chlorosis
HOST: Citrus (sp. unknown)
Leafhopper (Oncometopia nigricans) vector of Xylella fastidiosa, which transmits citrus variegated chlorosis.

Citrus variegated chlorosis | Citrus (sp. unknown)
DISEASE: Citrus variegated chlorosis
HOST: Citrus (sp. unknown) (Citrus sp.)
PATHOGEN: Xylella fastidiosa
SOURCE: D. Hopkins
DISEASE: Citrus variegated chlorosis
HOST: Citrus (Orange)
Small, hard, diseased fruit interspersed with three normal fruits for comparison. Diseased fruit often exhibit sunburn symptoms.

Citrus variegated chlorosis | Citrus (Orange)
DISEASE: Citrus variegated chlorosis
HOST: Citrus (Orange) (Citrus sinensis)
PATHOGEN: Xylella fastidiosa
SOURCE: M. J. G. Beretta
DISEASE: Citrus variegated chlorosis
HOST: Citrus (Orange)
Diseased tree with sparse foliage.

Citrus variegated chlorosis | Citrus (Orange)
DISEASE: Citrus variegated chlorosis
HOST: Citrus (Orange) (Citrus sinensis)
PATHOGEN: Xylella fastidiosa
SOURCE: S. Purcell
DISEASE: Citrus variegated chlorosis
HOST: Citrus (Orange)
Typical symptoms of the disease are discoloration of infected leaves, brown spots on lower sides of leaves, chlorosis on upper sides, and undersized fruit (left). Healthy fruit and leaves (right).

Citrus variegated chlorosis | Citrus (Orange)
DISEASE: Citrus variegated chlorosis
HOST: Citrus (Orange) (Citrus sinensis)
PATHOGEN: Xylella fastidiosa
SOURCE: S. Purcell