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: Australian citrus dieback
HOST: Citrus (Grapefruit)
Leaves with mottled chlorosis.
Australian citrus dieback | Citrus (Grapefruit)
DISEASE: Australian citrus dieback
HOST: Citrus (Grapefruit) (Citrus paradisi)
PATHOGEN: 'Candidatus Phytoplasma' sp.
PATHOGEN SYNONYM: Phytoplasma (undefined)
SOURCE: P. Broadbent
DISEASE: Australian citrus dieback
HOST: Citrus (Grapefruit)
Late stage of disease. Note yellowing of leaf veins and entire leaves.
Australian citrus dieback | Citrus (Grapefruit)
DISEASE: Australian citrus dieback
HOST: Citrus (Grapefruit) (Citrus paradisi)
PATHOGEN: 'Candidatus Phytoplasma' sp.
PATHOGEN SYNONYM: Phytoplasma (undefined)
SOURCE: P. Broadbent
DISEASE: Bacterial leaf spot
HOST: Alfalfa
Stems with necrotic lesions.
Bacterial leaf spot | Alfalfa
DISEASE: Bacterial leaf spot
HOST: Alfalfa (Medicago sativa)
PATHOGEN: Xanthomonas alfalfae subsp. alfalfae
PATHOGEN SYNONYM: Xanthomonas campestris pv. alfalfae
SOURCE: APS
DISEASE: Bacterial leaf spot
HOST: Alfalfa
Leaves with brown necrotic spots. Stems have water-soaked spots.
Bacterial leaf spot | Alfalfa
DISEASE: Bacterial leaf spot
HOST: Alfalfa (Medicago sativa)
PATHOGEN: Xanthomonas alfalfae subsp. alfalfae
PATHOGEN SYNONYM: Xanthomonas campestris pv. alfalfae
SOURCE: S. Thomson
DISEASE: Bacterial leaf spot
HOST: Alfalfa
Leaves with both water-soaked and necrotic spots.
Bacterial leaf spot | Alfalfa
DISEASE: Bacterial leaf spot
HOST: Alfalfa (Medicago sativa)
PATHOGEN: Xanthomonas alfalfae subsp. alfalfae
PATHOGEN SYNONYM: Xanthomonas campestris pv. alfalfae
SOURCE: APS
DISEASE: Bacterial leaf spot
HOST: Alfalfa
Leaves with necrotic, brownish paperlike areas.
Bacterial leaf spot | Alfalfa
DISEASE: Bacterial leaf spot
HOST: Alfalfa (Medicago sativa)
PATHOGEN: Xanthomonas alfalfae subsp. alfalfae
PATHOGEN SYNONYM: Xanthomonas campestris pv. alfalfae
SOURCE: APS
DISEASE: Bacterial leaf spot
HOST: Nephthytis
Leaf with concentric rings of dark tissues. There has been confusion of the causal agent with Dickeya sp., which also causes mushy leaf spots.
Bacterial leaf spot | Nephthytis
DISEASE: Bacterial leaf spot
HOST: Nephthytis (Syngonium podophyllum)
PATHOGEN: Pectobacterium carotovorum
PATHOGEN SYNONYM: Erwinia carotovora subsp. carotovora
SOURCE: A. Chase
DISEASE: Bacterial leaf spot
HOST: Nephthytis
Water-soaked tissues and large, dark brown necrotic areas at leaf margins. Healthy (center leaf).
Bacterial leaf spot | Nephthytis
DISEASE: Bacterial leaf spot
HOST: Nephthytis (Syngonium podophyllum)
PATHOGEN: Pseudomonas cichorii
SOURCE: S. Thomson