DISEASE: Aster yellows
HOST: Potato
Chlorotic and stunted foliage with necrotic leaf margins. Other symptoms may be phyllody, virescence, purple or yellow pigmentation, and rolling of leaflets.

Aster yellows | Potato
DISEASE: Aster yellows
HOST: Potato (Solanum tuberosum)
PATHOGEN: 'Candidatus Phytoplasma asteris'
PATHOGEN SYNONYM: Phytoplasma Aster yellows group
SOURCE: S. Thomson
DISEASE: Aster yellows
HOST: Potato
Stunted, chlorotic plants (left) with stiff, rolled leaves.

Aster yellows | Potato
DISEASE: Aster yellows
HOST: Potato (Solanum tuberosum)
PATHOGEN: 'Candidatus Phytoplasma asteris'
PATHOGEN SYNONYM: Phytoplasma Aster yellows group
SOURCE: S. Thomson
DISEASE: Aster yellows
HOST: Potato
Diseased plant with malformed tubers.

Aster yellows | Potato
DISEASE: Aster yellows
HOST: Potato (Solanum tuberosum)
PATHOGEN: 'Candidatus Phytoplasma asteris'
PATHOGEN SYNONYM: Phytoplasma Aster yellows group
SOURCE: S. Thomson
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: Bacterial leaf spot (Blight)
HOST: Poinsettia
Blighted leaves and stems.

Bacterial leaf spot (Blight) | Poinsettia
DISEASE: Bacterial leaf spot (Blight)
HOST: Poinsettia (Euphorbia pulcherrima)
PATHOGEN: Curtobacterium flaccumfaciens pv. poinsettiae
SOURCE: APS
DISEASE: Bacterial leaf spot (Blight)
HOST: Poinsettia
Poinsettia with diseased stem. Woody stems may have a yellowed cortex and dark vascular tissues. The stem tip may curve with deformed terminal leaves.

Bacterial leaf spot (Blight) | Poinsettia
DISEASE: Bacterial leaf spot (Blight)
HOST: Poinsettia (Euphorbia pulcherrima)
PATHOGEN: Curtobacterium flaccumfaciens pv. poinsettiae
SOURCE: APS
DISEASE: Bacterial leaf spot (Blight)
HOST: Poinsettia
Leaves with small, dark spots, an early stage of disease.

Bacterial leaf spot (Blight) | Poinsettia
DISEASE: Bacterial leaf spot (Blight)
HOST: Poinsettia (Euphorbia pulcherrima)
PATHOGEN: Curtobacterium flaccumfaciens pv. poinsettiae
SOURCE: A. Alvarez
DISEASE: Bacterial leaf spot
HOST: Citrus (sp. unknown)
Leaf with flat, spreading lesions.

Bacterial leaf spot | Citrus (sp. unknown)
DISEASE: Bacterial leaf spot
HOST: Citrus (sp. unknown) (Citrus sp.)
PATHOGEN: Xanthomonas alfalfae subsp. citrumelonis
PATHOGEN SYNONYM: Xanthomonas alfalfae subsp. citrumelo
SOURCE: J. H. Graham