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 blast and fruit spot
HOST: Avocado
White bacterial ooze on surface of fruit. Pseudomonas strains that cause canker likely differ from those that infect fruit and leaves.

Bacterial blast and fruit spot | Avocado
DISEASE: Bacterial blast and fruit spot
HOST: Avocado (Persea americana)
PATHOGEN: Pseudomonas syringae
SOURCE: L. Fucikovsky
DISEASE: Bacterial canker
HOST: Avocado
Cankers on trunk.

Bacterial canker | Avocado
DISEASE: Bacterial canker
HOST: Avocado (Persea americana)
PATHOGEN: Xanthomonas campestris
SOURCE: H. Ohr
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 leaf spot
HOST: Schefflera
Leaf with water-soaked lesions.

Bacterial leaf spot | Schefflera
DISEASE: Bacterial leaf spot
HOST: Schefflera (Schefflera actinophylla)
PATHOGEN: Xanthomonas hortorum pv. hederae
PATHOGEN SYNONYM: Xanthomonas campestris pv. hederae
SOURCE: M. Gleason
DISEASE: Bacterial leaf spot
HOST: Schefflera
Leaf with large, grayish necrotic areas.

Bacterial leaf spot | Schefflera
DISEASE: Bacterial leaf spot
HOST: Schefflera (Schefflera actinophylla)
PATHOGEN: Xanthomonas hortorum pv. hederae
PATHOGEN SYNONYM: Xanthomonas campestris pv. hederae
SOURCE: A. Chase
DISEASE: Bacterial leaf spot
HOST: Schefflera
Leaf with many small, pinpoint-sized lesions and a few large lesions.

Bacterial leaf spot | Schefflera
DISEASE: Bacterial leaf spot
HOST: Schefflera (Schefflera arboricola)
PATHOGEN: Xanthomonas hortorum pv. hederae
PATHOGEN SYNONYM: Xanthomonas campestris pv. hederae
SOURCE: A. Chase