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 fasciation (Leafy gall)
HOST: Gladiolus
Bacterial fasciation of gladiolus.

Bacterial fasciation (Leafy gall) | Gladiolus
DISEASE: Bacterial fasciation (Leafy gall)
HOST: Gladiolus (Gladiolus hortulanus)
PATHOGEN: Rhodococcus fascians
SOURCE: H. van Hoof, M. Geesteranus
DISEASE: Bacterial leaf spot
HOST: Crown-of-thorns
Leaves with brown lesions surrounded by bright yellow halos.

Bacterial leaf spot | Crown-of-thorns
DISEASE: Bacterial leaf spot
HOST: Crown-of-thorns (Euphorbia milii)
PATHOGEN: Xanthomonas axonopodis pv. poinsettiicola
PATHOGEN SYNONYM: Xanthomonas campestris pv. poinsettiicola
SOURCE: APS
DISEASE: Bacterial scab
HOST: Gladiolus
Gladiolus bulb with brownish to dark brown, sunken scabs.

Bacterial scab | Gladiolus
DISEASE: Bacterial scab
HOST: Gladiolus (Gladiolus sp.)
PATHOGEN: Burkholderia gladioli pv. gladioli
PATHOGEN SYNONYM: Pseudomonas gladioli pv. gladioli
SOURCE: Plant Protection Service of the Netherlands
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