RESULTS

(7)

FILTER

DISEASE: Aster yellows

HOST: Squash

Diagnostic characteristics for the disease are yellowing of young leaves, proliferation of secondary shoots, and rigid erect habit. Leaves are misshapen and smaller than normal and have stiff, thick laminae.

Aster yellows | Squash

DISEASE: Aster yellows

HOST: Squash (Cucurbita sp.)

PATHOGEN: 'Candidatus Phytoplasma asteris'

PATHOGEN SYNONYM: Phytoplasma Aster yellows group

SOURCE: S. Miller

DISEASE: Bacterial blight

HOST: Bindweed

Water-soaked areas and angular leaf spots with yellow ooze.

Bacterial blight | Bindweed

DISEASE: Bacterial blight

HOST: Bindweed (Convolvulus arvensis)

PATHOGEN: Xanthomonas campestris pv. convolvuli

SOURCE: S. Mohan

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 wilt

HOST: Squash

Field with severe symptoms of wilt. Foliage often is chlorotic and leaf margins may be chlorotic and necrotic before plant death. Bacterial ooze may be seen streaming from the xylem when infected stems are cut.

Bacterial wilt | Squash

DISEASE: Bacterial wilt

HOST: Squash (Cucurbita maxima)

PATHOGEN: Erwinia tracheiphila

SOURCE: B. Jacobsen, M. Shurtleff

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: 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