DISEASE: Bacterial blight
HOST: Poppy
The disease begins with water-soaked lesions that turn brown to black. They may be surrounded by a translucent ring. Buds, leaves, flowers, and pods are affected.

Bacterial blight | Poppy
DISEASE: Bacterial blight
HOST: Poppy (Eschscholzia californica)
PATHOGEN: Xanthomonas campestris pv. papavericola
SOURCE: M. Daughtrey
DISEASE: Bacterial canker
HOST: Hazelnut
Primary symptoms are failure of buds to break and withering and death of new foliage in spring. Dead leaves remain attached to limbs after normal leaf fall.

Bacterial canker | Hazelnut
DISEASE: Bacterial canker
HOST: Hazelnut (Corylus americana)
PATHOGEN: Pseudomonas syringae pv. avellanae
PATHOGEN SYNONYM: Pseudomonas avellanae
SOURCE: P. Psalidas
DISEASE: Bunch disease (Witches'-broom)
HOST: Butternut
Bunch disease of butternut.

Bunch disease (Witches'-broom) | Butternut
DISEASE: Bunch disease (Witches'-broom)
HOST: Butternut (Juglans cinerea)
PATHOGEN: 'Candidatus Phytoplasma pruni'
PATHOGEN SYNONYM: Phytoplasma X-disease group
SOURCE: W. Sinclair
DISEASE: Bunch disease
HOST: Pecan
Pecan exhibiting bunch symptoms at ends of branches. This disease is thought to be caused by a phytoplasma similar to the walnut bunch pathogen in the X-disease group.

Bunch disease | Pecan
DISEASE: Bunch disease
HOST: Pecan (Carya illinoinensis)
PATHOGEN: 'Candidatus Phytoplasma pruni'
PATHOGEN SYNONYM: Phytoplasma X-disease group
SOURCE: W. Sinclair
DISEASE: Bunch disease
HOST: Pecan
Severe case of bunch disease. Note bunches of foliage.

Bunch disease | Pecan
DISEASE: Bunch disease
HOST: Pecan (Carya illinoinensis)
PATHOGEN: 'Candidatus Phytoplasma pruni'
PATHOGEN SYNONYM: Phytoplasma X-disease group
SOURCE: P. Bertrand
DISEASE: Bunch disease
HOST: Walnut
Foliage with bunchlike symptoms.

Bunch disease | Walnut
DISEASE: Bunch disease
HOST: Walnut (Juglans nigra)
PATHOGEN: 'Candidatus Phytoplasma pruni'
PATHOGEN SYNONYM: Phytoplasma X-disease group
SOURCE: R. Green
DISEASE: Bunch disease
HOST: Walnut
Twisted shoot with yellow leaves, a symptom of bunch disease.

Bunch disease | Walnut
DISEASE: Bunch disease
HOST: Walnut (Juglans regia 'Hartley')
PATHOGEN: 'Candidatus Phytoplasma pruni'
PATHOGEN SYNONYM: Phytoplasma X-disease group
SOURCE: E. Braun
DISEASE: Bunch disease
HOST: Walnut
Tree with advanced disease symptoms of branch and twig death.

Bunch disease | Walnut
DISEASE: Bunch disease
HOST: Walnut (Juglans microcarpa)
PATHOGEN: 'Candidatus Phytoplasma pruni'
PATHOGEN SYNONYM: Phytoplasma X-disease group
SOURCE: W. Sinclair