DISEASE: Aster yellows
HOST: Marigold
Infected plant (left) with yellowing and stunting.

Aster yellows | Marigold
DISEASE: Aster yellows
HOST: Marigold (Tagetes erecta)
PATHOGEN: 'Candidatus Phytoplasma asteris'
PATHOGEN SYNONYM: Phytoplasma Aster yellows group
SOURCE: M. Shurtleff
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: Basal rot
HOST: Cabbage
Severe basal rot of Chinese cabbage.

Basal rot | Cabbage
DISEASE: Basal rot
HOST: Cabbage (Brassica pekinensis)
PATHOGEN: Pectobacterium carotovorum
PATHOGEN SYNONYM: Erwinia carotovora subsp. carotovora
SOURCE: Y. Sakamoto, M. Goto
DISEASE: Basal rot
HOST: Cabbage
Chinese cabbage with rotted base.

Basal rot | Cabbage
DISEASE: Basal rot
HOST: Cabbage (Brassica pekinensis)
PATHOGEN: Pectobacterium carotovorum
PATHOGEN SYNONYM: Erwinia carotovora subsp. carotovora
SOURCE: Y. Sakamoto, M. Goto
DISEASE: Pseudomonas leaf spot
HOST: Marigold
Marigolds with yellow apical chlorosis attributed to toxin production by the pathogen.

Pseudomonas leaf spot | Marigold
DISEASE: Pseudomonas leaf spot
HOST: Marigold (Tagetes erecta)
PATHOGEN: Pseudomonas syringae pv. tagetis
SOURCE: R. Durbin
DISEASE: Pseudomonas leaf spot
HOST: Marigold
Chlorotic leaves with total loss of chlorophyll. Disease is also known as toxic chlorosis.

Pseudomonas leaf spot | Marigold
DISEASE: Pseudomonas leaf spot
HOST: Marigold (Tagetes erecta)
PATHOGEN: Pseudomonas syringae pv. tagetis
SOURCE: R. Durbin
DISEASE: Pseudomonas leaf spot
HOST: Primrose
Leaf with brownish red spots and reddening of adjacent areas. Disease begins as small, water-soaked lesions that later coalesce into large necrotic spots.

Pseudomonas leaf spot | Primrose
DISEASE: Pseudomonas leaf spot
HOST: Primrose (Primula sp.)
PATHOGEN: Pseudomonas syringae pv. primulae
SOURCE: APS