DISEASE: Bacterial canker
HOST: Hazelnut
Primary symptoms are failure of buds to break and withering and death of new foliage in spring. Dead leaves remain attached to limbs after normal leaf fall.

Bacterial canker | Hazelnut
DISEASE: Bacterial canker
HOST: Hazelnut (Corylus americana)
PATHOGEN: Pseudomonas syringae pv. avellanae
PATHOGEN SYNONYM: Pseudomonas avellanae
SOURCE: P. Psalidas
DISEASE: Bacterial leaf spot
HOST: Cabbage
Cabbage leaves with irregular, brownish lesions. The bacterium does not invade vascular tissues.

Bacterial leaf spot | Cabbage
DISEASE: Bacterial leaf spot
HOST: Cabbage (Brassica oleracea var. capitata)
PATHOGEN: Xanthomonas campestris pv. armoraciae
SOURCE: R. Gitaitis
DISEASE: Bacterial leaf spot
HOST: Cabbage
Water-soaked lesions on underside of leaf (left), and water-soaked, large necrotic lesions on upper side (right).

Bacterial leaf spot | Cabbage
DISEASE: Bacterial leaf spot
HOST: Cabbage (Brassica oleracea var. capitata)
PATHOGEN: Xanthomonas campestris pv. armoraciae
SOURCE: R. Campbell
DISEASE: Bacterial leaf spot
HOST: Cabbage
Leaf with various stages of lesion development, including water-soaked lesions.

Bacterial leaf spot | Cabbage
DISEASE: Bacterial leaf spot
HOST: Cabbage (Brassica oleracea var. capitata)
PATHOGEN: Xanthomonas campestris pv. armoraciae
SOURCE: R. Campbell
DISEASE: Bacterial leaf spot
HOST: Cabbage
Cabbage leaves with many irregular, dark, water-soaked lesions.

Bacterial leaf spot | Cabbage
DISEASE: Bacterial leaf spot
HOST: Cabbage (Brassica oleracea var. capitata)
PATHOGEN: Xanthomonas campestris pv. armoraciae
SOURCE: R. Gitaitis
DISEASE: Bacterial leaf spot
HOST: Cabbage
Necrotic, light tan leaf spots, a late stage in disease development.

Bacterial leaf spot | Cabbage
DISEASE: Bacterial leaf spot
HOST: Cabbage (Brassica pekinensis)
PATHOGEN: Xanthomonas campestris pv. armoraciae
SOURCE: R. Campbell
DISEASE: Bacterial leaf spot
HOST: Turnip
Leaf with many tan, dry-appearing, angular spots.

Bacterial leaf spot | Turnip
DISEASE: Bacterial leaf spot
HOST: Turnip (Brassica rapa)
PATHOGEN: Xanthomonas campestris pv. armoraciae
SOURCE: R. Campbell
DISEASE: Bois noir disease
HOST: Grape
Severe symptoms of triangular-trapezoid-shaped leaves with desiccated appearance.

Bois noir disease | Grape
DISEASE: Bois noir disease
HOST: Grape (Vitis vinifera)
PATHOGEN: 'Candidatus Phytoplasma solani'
PATHOGEN SYNONYM: Phytoplasma Stolbur group
SOURCE: W. Schweigkofler
DISEASE: Bois noir disease
HOST: Grape
Leaves with disease symptoms identical to flavescence doree, a yellows disease caused by a different phytoplasma. The latter has a slightly different host range and is transmitted by a leafhopper.

Bois noir disease | Grape
DISEASE: Bois noir disease
HOST: Grape (Vitis vinifera)
PATHOGEN: 'Candidatus Phytoplasma solani'
PATHOGEN SYNONYM: Phytoplasma Stolbur group
SOURCE: W. Schweigkofler