DISEASE: Aster yellows
HOST: Chrysanthemum
Stunted diseased plant with small distorted flowers.

Aster yellows | Chrysanthemum
DISEASE: Aster yellows
HOST: Chrysanthemum (Chrysanthemum morifolium)
PATHOGEN: 'Candidatus Phytoplasma asteris'
PATHOGEN SYNONYM: Phytoplasma Aster yellows group
SOURCE: B. Raju, M. Davis
DISEASE: Aster yellows
HOST: Squash
Diagnostic characteristics for the disease are yellowing of young leaves, proliferation of secondary shoots, and rigid erect habit. Leaves are misshapen and smaller than normal and have stiff, thick laminae.

Aster yellows | Squash
DISEASE: Aster yellows
HOST: Squash (Cucurbita sp.)
PATHOGEN: 'Candidatus Phytoplasma asteris'
PATHOGEN SYNONYM: Phytoplasma Aster yellows group
SOURCE: S. Miller
DISEASE: Bacterial black leaf spot
HOST: Clover
White clover with brown necrotic spots.

Bacterial black leaf spot | Clover
DISEASE: Bacterial black leaf spot
HOST: Clover (Trifolium repens)
PATHOGEN: Burkholderia andropogonis
PATHOGEN SYNONYM: Pseudomonas andropogonis
SOURCE: M. Goto
DISEASE: Bacterial black leaf spot
HOST: Clover
White clover leaves with brownish spots and some yellowing occurring at the margins.

Bacterial black leaf spot | Clover
DISEASE: Bacterial black leaf spot
HOST: Clover (Trifolium repens)
PATHOGEN: Burkholderia andropogonis
PATHOGEN SYNONYM: Pseudomonas andropogonis
SOURCE: R. Gitaitis
DISEASE: Bacterial fasciation (Leafy gall)
HOST: Chrysanthemum
Fasciation of chrysanthemum.

Bacterial fasciation (Leafy gall) | Chrysanthemum
DISEASE: Bacterial fasciation (Leafy gall)
HOST: Chrysanthemum (Chrysanthemum morifolium)
PATHOGEN: Rhodococcus fascians
SOURCE: M. Schroth
DISEASE: Bacterial wilt and blight
HOST: Chrysanthemum
Plants with characteristic symptoms of wilt.

Bacterial wilt and blight | Chrysanthemum
DISEASE: Bacterial wilt and blight
HOST: Chrysanthemum (Chrysanthemum morifolium)
PATHOGEN: Dickeya sp.
PATHOGEN SYNONYM: Erwinia chrysanthemi
SOURCE: A. Alvarez
DISEASE: Crown gall
HOST: Chrysanthemum
Galls on chrysanthemum stem.

Crown gall | Chrysanthemum
DISEASE: Crown gall
HOST: Chrysanthemum (Chrysanthemum morifolium)
PATHOGEN: Agrobacterium tumefaciens
PATHOGEN SYNONYM: Rhizobium sp.
SOURCE: K. Ohta, M. Goto
DISEASE: Rugose leaf curl
HOST: Clover
Two rugose, distorted white clover leaves and a healthy leaf. Rugose leaf curl is caused by an unidentified phloem-infecting bacterium.

Rugose leaf curl | Clover
DISEASE: Rugose leaf curl
HOST: Clover (Trifolium repens)
PATHOGEN: Phloem-infecting bacterium
SOURCE: D. Teakle