DISEASE: Aster yellows
HOST: Wheat
Healthy head (left) and diseased head (right). Diseased seedlings may die within 2 to 3 weeks. Infected heads of surviving plants are small and sterile, with distorted awns.
Aster yellows | Wheat
DISEASE: Aster yellows
HOST: Wheat (Triticum aestivum)
PATHOGEN: 'Candidatus Phytoplasma asteris'
PATHOGEN SYNONYM: Phytoplasma Aster yellows group
SOURCE: L. N. Chiykowski
DISEASE: Bacterial blight
HOST: Poppy
The disease begins with water-soaked lesions that turn brown to black. They may be surrounded by a translucent ring. Buds, leaves, flowers, and pods are affected.
Bacterial blight | Poppy
DISEASE: Bacterial blight
HOST: Poppy (Eschscholzia californica)
PATHOGEN: Xanthomonas campestris pv. papavericola
SOURCE: M. Daughtrey
DISEASE: Bacterial leaf blight
HOST: Wheat
Diseased leaves with whitish blotches. Initial water-soaked spots become necrotic and progress from gray-green to tannish white.
Bacterial leaf blight | Wheat
DISEASE: Bacterial leaf blight
HOST: Wheat (Triticum aestivum)
PATHOGEN: Pseudomonas syringae pv. syringae
SOURCE: J. Otta
DISEASE: Bacterial leaf blight
HOST: Wheat
Diseased leaves with whitish blotches. The disease begins as water-soaked spots and then become necrotic and progresses from gray-green to tannish white.
Bacterial leaf blight | Wheat
DISEASE: Bacterial leaf blight
HOST: Wheat (Triticum aestivum)
PATHOGEN: Pseudomonas syringae pv. syringae
SOURCE: L. Claflin
DISEASE: Bacterial leaf blight
HOST: Wheat
Leaves with reddish tan necrotic lesions.
Bacterial leaf blight | Wheat
DISEASE: Bacterial leaf blight
HOST: Wheat (Triticum aestivum)
PATHOGEN: Pseudomonas syringae pv. syringae
SOURCE: L. Claflin
DISEASE: Bacterial mosaic
HOST: Wheat
Diseased leaves with mosaic pattern exhibiting various amounts of yellowing. Leaves were artificially inoculated by vacuum infiltration.
Bacterial mosaic | Wheat
DISEASE: Bacterial mosaic
HOST: Wheat (Triticum aestivum)
PATHOGEN: Clavibacter michiganensis subsp. tessellarius
SOURCE: A. Vidaver
DISEASE: Bacterial wilt
HOST: Grass
Wilted and dead patches of diseased creeping bent grass (Toronto grass) on golf green.
Bacterial wilt | Grass
DISEASE: Bacterial wilt
HOST: Grass (Agrostis stolonifera)
PATHOGEN: Xanthomonas translucens pv. poae
SOURCE: D. Roberts
DISEASE: Bacterial wilt
HOST: Grass
Irregular disease patterns on golf green. The cultivars Toronto, Cohansey, and Nimisilia are primary hosts of the disease.
Bacterial wilt | Grass
DISEASE: Bacterial wilt
HOST: Grass (Agrostis stolonifera)
PATHOGEN: Xanthomonas translucens pv. poae
SOURCE: D. Roberts
DISEASE: Black chaff (Bacterial leaf streak)
HOST: Wheat
Water-soaked stage of leaf streak.
Black chaff (Bacterial leaf streak) | Wheat
DISEASE: Black chaff (Bacterial leaf streak)
HOST: Wheat (Triticum aestivum)
PATHOGEN: Xanthomonas translucens pv. undulosa
SOURCE: S. Thomson