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: Hydrangea (Oak-leaf)
Leaf with individual brown necrotic lesions and coalesced lesions that formed large necrotic areas. The disease is caused by an unclassified xanthomonad.
Bacterial leaf spot | Hydrangea (Oak-leaf)
DISEASE: Bacterial leaf spot
HOST: Hydrangea (Oak-leaf) (Hydrangea quercifolia)
PATHOGEN: Xanthomonas campestris
SOURCE: W. Uddin, W. Sinclair
DISEASE: Foamy canker
HOST: Koa
Foamy canker of koa is associated with bacteria and yeast. The causal agent has not been identified.
Foamy canker | Koa
DISEASE: Foamy canker
HOST: Koa (Acacia koa)
PATHOGEN: Causal agent unknown
SOURCE: H. Keyser
DISEASE: Foamy canker
HOST: Koa
Dieback of koa tree. The causal agent has not been identified.
Foamy canker | Koa
DISEASE: Foamy canker
HOST: Koa (Acacia koa)
PATHOGEN: Causal agent unknown
SOURCE: H. Keyser
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