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 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: Bacterial leaf spot
HOST: Schefflera
Leaf with water-soaked lesions.
Bacterial leaf spot | Schefflera
DISEASE: Bacterial leaf spot
HOST: Schefflera (Schefflera actinophylla)
PATHOGEN: Xanthomonas hortorum pv. hederae
PATHOGEN SYNONYM: Xanthomonas campestris pv. hederae
SOURCE: M. Gleason
DISEASE: Bacterial leaf spot
HOST: Schefflera
Leaf with large, grayish necrotic areas.
Bacterial leaf spot | Schefflera
DISEASE: Bacterial leaf spot
HOST: Schefflera (Schefflera actinophylla)
PATHOGEN: Xanthomonas hortorum pv. hederae
PATHOGEN SYNONYM: Xanthomonas campestris pv. hederae
SOURCE: A. Chase
DISEASE: Bacterial leaf spot
HOST: Schefflera
Leaf with many small, pinpoint-sized lesions and a few large lesions.
Bacterial leaf spot | Schefflera
DISEASE: Bacterial leaf spot
HOST: Schefflera (Schefflera arboricola)
PATHOGEN: Xanthomonas hortorum pv. hederae
PATHOGEN SYNONYM: Xanthomonas campestris pv. hederae
SOURCE: A. Chase
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: Crown gall
HOST: Poppy
Crown gall of California poppy, a native wild flower.
Crown gall | Poppy
DISEASE: Crown gall
HOST: Poppy (Eschscholzia californica)
PATHOGEN: Agrobacterium tumefaciens
PATHOGEN SYNONYM: Rhizobium sp.
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