DISEASE: Bacterial blight
HOST: Hazelnut
Diseased young tree with discoloration of the cambium. Dieback of young twigs and branches is characteristic. Other typical symptoms are bud and twig necrosis and small, angular or round, water-soaked leaf spots.
Bacterial blight | Hazelnut
DISEASE: Bacterial blight
HOST: Hazelnut (Corylus americana)
PATHOGEN: Xanthomonas arboricola pv. corylina
SOURCE: J. Pscheidt
DISEASE: Bacterial blight
HOST: Photinia
Symptoms of photinia bud blight shown here are similar to those of blast of pear and apple, caused by Pseudomonas syringae pv. syringae.
Bacterial blight | Photinia
DISEASE: Bacterial blight
HOST: Photinia (Photinia glabra)
PATHOGEN: Pseudomonas syringae pv. photiniae
SOURCE: M. Goto
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: Bacterial leaf scorch
HOST: Pecan
Pecan with necrotic scorched leaves with distinct dark lines between healthy and diseased tissues.
Bacterial leaf scorch | Pecan
DISEASE: Bacterial leaf scorch
HOST: Pecan (Carya illinoinensis)
PATHOGEN: Xylella fastidiosa
SOURCE: T. Brenneman
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: Fire blight
HOST: Photinia
Fire blight cankers on photinia.
Fire blight | Photinia
DISEASE: Fire blight
HOST: Photinia (Photinia fraseri)
PATHOGEN: Erwinia amylovora
SOURCE: M. Schroth
DISEASE: Fire blight
HOST: Photinia
Typical crook neck symptom of infected shoot.
Fire blight | Photinia
DISEASE: Fire blight
HOST: Photinia (Photinia fraseri)
PATHOGEN: Erwinia amylovora
SOURCE: M. Schroth
DISEASE: Witches'-broom
HOST: Pecan
Diseased pecan with short branches on trunk with witches'-broom appearance.
Witches'-broom | Pecan
DISEASE: Witches'-broom
HOST: Pecan (Carya illinoinensis)
PATHOGEN: 'Candidatus Phytoplasma pruni'
PATHOGEN SYNONYM: Phytoplasma X-disease group
SOURCE: P. Bertrand