DISEASE: Bacterial blight (Brown stem)
HOST: Celery
Lesions are necrotic and circular to angular. Some have yellowish halos. Older lesions become brown and dry.

Bacterial blight (Brown stem) | Celery
DISEASE: Bacterial blight (Brown stem)
HOST: Celery (Apium graveolens)
PATHOGEN: Pseudomonas cichorii
SOURCE: R. Raid
DISEASE: Bacterial blight (Brown stem)
HOST: Celery
Ooze from lesion on celery leaf.

Bacterial blight (Brown stem) | Celery
DISEASE: Bacterial blight (Brown stem)
HOST: Celery (Apium graveolens)
PATHOGEN: Pseudomonas cichorii
SOURCE: R. Raid
DISEASE: Bacterial blight (Brown stem)
HOST: Celery
Characteristic brown discoloration of petioles, which is more evident on inside of petiole close to the crown. Parenchyma tissues are firm and brown.

Bacterial blight (Brown stem) | Celery
DISEASE: Bacterial blight (Brown stem)
HOST: Celery (Apium graveolens)
PATHOGEN: Pseudomonas cichorii
SOURCE: K. Pernezny
DISEASE: Oleander knot
HOST: Oleander
Oleander with small knots/galls on leaf and stems.

Oleander knot | Oleander
DISEASE: Oleander knot
HOST: Oleander (Nerium oleander)
PATHOGEN: Pseudomonas savastanoi pv. nerii
SOURCE: W. Sinclair
DISEASE: Oleander knot
HOST: Oleander
Young stem with knots/galls.

Oleander knot | Oleander
DISEASE: Oleander knot
HOST: Oleander (Nerium oleander)
PATHOGEN: Pseudomonas savastanoi pv. nerii
SOURCE: R. Raabe
DISEASE: Oleander knot
HOST: Oleander
Leaf with early stage of knot/gall formation.

Oleander knot | Oleander
DISEASE: Oleander knot
HOST: Oleander (Nerium oleander)
PATHOGEN: Pseudomonas savastanoi pv. nerii
SOURCE: R. Raabe
DISEASE: Oleander knot
HOST: Oleander
Infected flowers with small knots/galls and necroses.

Oleander knot | Oleander
DISEASE: Oleander knot
HOST: Oleander (Nerium oleander)
PATHOGEN: Pseudomonas savastanoi pv. nerii
SOURCE: W. Sinclair
DISEASE: Witches'-broom
HOST: Alfalfa
Alfalfa plant (center) exhibiting stunting and proliferation of stems. Other symptoms are small, rounded, chlorotic, often puckered leaves and a yellowish cast.

Witches'-broom | Alfalfa
DISEASE: Witches'-broom
HOST: Alfalfa (Medicago sativa)
PATHOGEN: 'Candidatus Phytoplasma trifolii'
PATHOGEN SYNONYM: Phytoplasma Clover proliferation group
SOURCE: S. Thomson
DISEASE: Witches'-broom
HOST: Alfalfa
Young plant (left) with small, numerous stems (witches'-broom). Healthy stems (right).

Witches'-broom | Alfalfa
DISEASE: Witches'-broom
HOST: Alfalfa (Medicago sativa)
PATHOGEN: 'Candidatus Phytoplasma trifolii'
PATHOGEN SYNONYM: Phytoplasma Clover proliferation group
SOURCE: S. Thomson