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: 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: Bacterial leaf spot
HOST: Zinnia
Leaf with small, brown spots.

Bacterial leaf spot | Zinnia
DISEASE: Bacterial leaf spot
HOST: Zinnia (Zinnia violacea)
PATHOGEN: Xanthomonas campestris pv. zinniae
SOURCE: M. Goto
DISEASE: Bacterial leaf spot
HOST: Zinnia
Leaf with blackish, necrotic, angular spots.

Bacterial leaf spot | Zinnia
DISEASE: Bacterial leaf spot
HOST: Zinnia (Zinnia violacea)
PATHOGEN: Xanthomonas campestris pv. zinniae
SOURCE: M. Daughtrey
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