DISEASE: Alfalfa dwarf
HOST: Alfalfa
Alfalfa dwarf is characterized by stunted plants (left), usually dark blue-green in color. Xylem tissues become brown, especially when exposed to air.
Alfalfa dwarf | Alfalfa
DISEASE: Alfalfa dwarf
HOST: Alfalfa (Medicago sativa)
PATHOGEN: Xylella fastidiosa
SOURCE: R. M. Davis
DISEASE: Angular leaf spot
HOST: Cucumber
Yellowish diseased cucumbers with bacterial ooze.
Angular leaf spot | Cucumber
DISEASE: Angular leaf spot
HOST: Cucumber (Cucumis sativus)
PATHOGEN: Pseudomonas syringae pv. lachrymans
SOURCE: B. Jacobsen, M. Shurtleff
DISEASE: Angular leaf spot
HOST: Cucumber
Cucumber leaves with angular, tan lesions of various sizes.
Angular leaf spot | Cucumber
DISEASE: Angular leaf spot
HOST: Cucumber (Cucumis sativus)
PATHOGEN: Pseudomonas syringae pv. lachrymans
SOURCE: M. Goto
DISEASE: Angular leaf spot
HOST: Cucumber
Cucumber leaf with water-soaked lesions. Lesions extend until they meet a secondary vein, resulting in angular appearance.
Angular leaf spot | Cucumber
DISEASE: Angular leaf spot
HOST: Cucumber (Cucumis sativus)
PATHOGEN: Pseudomonas syringae pv. lachrymans
SOURCE: S. Thomson
DISEASE: Angular leaf spot
HOST: Cucumber
Cucumber leaf with dark lesions surrounded by halos, another common symptom.
Angular leaf spot | Cucumber
DISEASE: Angular leaf spot
HOST: Cucumber (Cucumis sativus)
PATHOGEN: Pseudomonas syringae pv. lachrymans
SOURCE: J. Young
DISEASE: Angular leaf spot
HOST: Cucumber
Leaves with yellowish, angular spots.
Angular leaf spot | Cucumber
DISEASE: Angular leaf spot
HOST: Cucumber (Cucumis sativus)
PATHOGEN: Pseudomonas syringae pv. lachrymans
SOURCE: J. Young
DISEASE: Angular leaf spot
HOST: Cucumber
Angular necrotic spots delimited by leaf veins.
Angular leaf spot | Cucumber
DISEASE: Angular leaf spot
HOST: Cucumber (Cucumis sativus)
PATHOGEN: Pseudomonas syringae pv. lachrymans
SOURCE: N. Tisserat, L. Claflin
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 leaf spot
HOST: Alfalfa
Stems with necrotic lesions.
Bacterial leaf spot | Alfalfa
DISEASE: Bacterial leaf spot
HOST: Alfalfa (Medicago sativa)
PATHOGEN: Xanthomonas alfalfae subsp. alfalfae
PATHOGEN SYNONYM: Xanthomonas campestris pv. alfalfae
SOURCE: APS