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 and blight
HOST: Fern
Leaf with small lesions that coalesced into large, reddish brown necrotic area.

Bacterial leaf spot and blight | Fern
DISEASE: Bacterial leaf spot and blight
HOST: Fern (Asplenium nidus)
PATHOGEN: Burkholderia gladioli pv. gladioli
PATHOGEN SYNONYM: Pseudomonas gladioli pv. gladioli
SOURCE: APS
DISEASE: Bacterial leaf spot
HOST: Fern
Fronds with diseased tips.

Bacterial leaf spot | Fern
DISEASE: Bacterial leaf spot
HOST: Fern (Davallia fejeensis)
PATHOGEN: Burkholderia gladioli pv. gladioli
PATHOGEN SYNONYM: Pseudomonas gladioli pv. gladioli
SOURCE: APS
DISEASE: Bacterial leaf spot
HOST: Fern
Leaf with large, dark, longitudinal necrotic areas that differ from symptoms normally described for this disease.

Bacterial leaf spot | Fern
DISEASE: Bacterial leaf spot
HOST: Fern (Asplenium nidus)
PATHOGEN: Pseudomonas asplenii
SOURCE: R. Raabe
DISEASE: Bacterial leaf spot
HOST: Fern
Frond with brown necrotic spots.

Bacterial leaf spot | Fern
DISEASE: Bacterial leaf spot
HOST: Fern (Platycerium bifurcatum)
PATHOGEN: Burkholderia gladioli pv. gladioli
PATHOGEN SYNONYM: Pseudomonas gladioli pv. gladioli
SOURCE: APS
DISEASE: Black rot
HOST: Rutabaga
Rutabaga with discoloration of vascular system.

Black rot | Rutabaga
DISEASE: Black rot
HOST: Rutabaga (Brassica napus var. napobrassica)
PATHOGEN: Xanthomonas campestris pv. campestris
SOURCE: M. Shurtleff
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