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: Verbena
Leaf with purple-brown necrotic spots.

Bacterial leaf spot | Verbena
DISEASE: Bacterial leaf spot
HOST: Verbena (Verbena sp.)
PATHOGEN: Pseudomonas sp.
SOURCE: R. Raabe
DISEASE: Bacterial stem and rhizome rot
HOST: Iris
Iris stem and rhizome with brown, discolored, rotted portions.

Bacterial stem and rhizome rot | Iris
DISEASE: Bacterial stem and rhizome rot
HOST: Iris (Iris sp.)
PATHOGEN: Burkholderia gladioli pv. gladioli
PATHOGEN SYNONYM: Pseudomonas gladioli pv. gladioli
SOURCE: R. Raabe
DISEASE: Bacterial stem and rhizome rot
HOST: Iris
Mushy rot of stems and rhizomes are characteristic of advanced stage of the disease.

Bacterial stem and rhizome rot | Iris
DISEASE: Bacterial stem and rhizome rot
HOST: Iris (Iris sp.)
PATHOGEN: Burkholderia gladioli pv. gladioli
PATHOGEN SYNONYM: Pseudomonas gladioli pv. gladioli
SOURCE: R. Raabe
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