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 wilt and dieback
HOST: Willow
Cross sections of the characteristic "watermark stain" of diseased wood. Wilt and dieback occur as disease progresses.
Bacterial wilt and dieback | Willow
DISEASE: Bacterial wilt and dieback
HOST: Willow (Salix sp.)
PATHOGEN: Brenneria salicis
PATHOGEN SYNONYM: Erwinia salicis
SOURCE: Y. Sakamoto, M. Goto
DISEASE: Bacterial wilt and dieback
HOST: Willow
Severely diseased tree with dieback symptoms.
Bacterial wilt and dieback | Willow
DISEASE: Bacterial wilt and dieback
HOST: Willow (Salix sp.)
PATHOGEN: Brenneria salicis
PATHOGEN SYNONYM: Erwinia salicis
SOURCE: Y. Sakamoto, M. Goto
DISEASE: Fire blight
HOST: Scarlet firethorn
Pyracantha with blighted twig. Ingress was probably through blossoms. Cankers commonly occur on branches.
Fire blight | Scarlet firethorn
DISEASE: Fire blight
HOST: Scarlet firethorn (Pyracantha coccinea)
PATHOGEN: Erwinia amylovora
SOURCE: W. Sinclair
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
DISEASE: Slime flux
HOST: Willow
Foam at site of infection. Slime fluxes are common but the causal agent has not been identified.
Slime flux | Willow
DISEASE: Slime flux
HOST: Willow (Salix sp.)
PATHOGEN: Causal agent unknown
SOURCE: S. Thomson
DISEASE: Witches'-broom
HOST: Willow
Twig with witches'-broom symptoms.
Witches'-broom | Willow
DISEASE: Witches'-broom
HOST: Willow (Salix sp.)
PATHOGEN: 'Candidatus Phytoplasma' sp.
PATHOGEN SYNONYM: Phytoplasma (undefined)
SOURCE: W. Sinclair