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: 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 brown spot
HOST: Mallotus
Leaf with small, rustylike lesions.
Bacterial brown spot | Mallotus
DISEASE: Bacterial brown spot
HOST: Mallotus (Mallotus japonicus)
PATHOGEN: Xanthomonas campestris pv. malloti
SOURCE: M. Goto
DISEASE: Bacterial brown spot
HOST: Mallotus
Leaf with tiny, light brown spots surrounded by chlorotic zones.
Bacterial brown spot | Mallotus
DISEASE: Bacterial brown spot
HOST: Mallotus (Mallotus japonicus)
PATHOGEN: Xanthomonas campestris pv. malloti
SOURCE: M. Kobayashi, 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 spot
HOST: Mallotus
Leaf with dark and water-soaked lesions along veins.
Bacterial leaf spot | Mallotus
DISEASE: Bacterial leaf spot
HOST: Mallotus (Mallotus japonicus)
PATHOGEN: Erwinia mallotivora
SOURCE: M. Kobayashi, M. Goto
DISEASE: Bacterial leaf spot
HOST: Mallotus
Leaves with water-soaking, and one also with dark spots surrounded by chlorotic tissues.
Bacterial leaf spot | Mallotus
DISEASE: Bacterial leaf spot
HOST: Mallotus (Mallotus japonicus)
PATHOGEN: Erwinia mallotivora
SOURCE: M. Kobayashi, M. Goto
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