DISEASE: Aster yellows
HOST: Watercress
Diseased watercress (left) and healthy plant (right).

Aster yellows | Watercress
DISEASE: Aster yellows
HOST: Watercress (Nasturtium officinale)
PATHOGEN: 'Candidatus Phytoplasma asteris'
PATHOGEN SYNONYM: Phytoplasma Aster yellows group
SOURCE: W. Borth
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: Aster yellows
HOST: Zinnia
Yellowing and shoot proliferation of foliage.

Aster yellows | Zinnia
DISEASE: Aster yellows
HOST: Zinnia (Zinnia violacea)
PATHOGEN: 'Candidatus Phytoplasma asteris'
PATHOGEN SYNONYM: Phytoplasma Aster yellows group
SOURCE: J. Forsberg, M. Shurtleff
DISEASE: Black rot
HOST: Broccoli
Blight and rot of flower buds.

Black rot | Broccoli
DISEASE: Black rot
HOST: Broccoli (Brassica oleracea var. italica)
PATHOGEN: Xanthomonas campestris pv. campestris
SOURCE: M. Shurtleff
DISEASE: Black rot
HOST: Cabbage
Typical yellow, V-shaped necrotic areas at leaf margins.

Black rot | Cabbage
DISEASE: Black rot
HOST: Cabbage (Brassica oleracea var. capitata)
PATHOGEN: Xanthomonas campestris pv. campestris
SOURCE: R. Gitaitis
DISEASE: Black rot
HOST: Cabbage
V-shaped, yellowish necrotic areas and blackened veins with small lesions at leaf margins .

Black rot | Cabbage
DISEASE: Black rot
HOST: Cabbage (Brassica oleracea var. capitata)
PATHOGEN: Xanthomonas campestris pv. campestris
SOURCE: A. Alvarez
DISEASE: Black rot
HOST: Cabbage
V-shaped necrotic areas at leaf margins and insect damage caused by diamondback moth.

Black rot | Cabbage
DISEASE: Black rot
HOST: Cabbage (Brassica oleracea var. capitata)
PATHOGEN: Xanthomonas campestris pv. campestris
SOURCE: M. Goto
DISEASE: Black rot
HOST: Cabbage
Black necrotic vascular bundles in stem tissues.

Black rot | Cabbage
DISEASE: Black rot
HOST: Cabbage (Brassica oleracea var. capitata)
PATHOGEN: Xanthomonas campestris pv. campestris
SOURCE: J. Cho