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 fruit blotch
HOST: Cantaloupe
Early stage of disease with discolored blotches on the surface.
Bacterial fruit blotch | Cantaloupe
DISEASE: Bacterial fruit blotch
HOST: Cantaloupe (Cucumis melo var. cantalupensis)
PATHOGEN: Acidovorax citrulli
PATHOGEN SYNONYM: Acidovorax avenae subsp. citrulli
SOURCE: D. B. Langston
DISEASE: Bacterial fruit blotch
HOST: Cantaloupe
View of disease path from rind to internal rotting of melon.
Bacterial fruit blotch | Cantaloupe
DISEASE: Bacterial fruit blotch
HOST: Cantaloupe (Cucumis melo var. cantalupensis)
PATHOGEN: Acidovorax citrulli
PATHOGEN SYNONYM: Acidovorax avenae subsp. citrulli
SOURCE: R. Gitaitis
DISEASE: Bacterial fruit blotch
HOST: Cantaloupe
Leaf spot stage. Lesions start small and may coalesce, forming large, brown necrotic areas.
Bacterial fruit blotch | Cantaloupe
DISEASE: Bacterial fruit blotch
HOST: Cantaloupe (Cucumis melo var. cantalupensis)
PATHOGEN: Acidovorax citrulli
PATHOGEN SYNONYM: Acidovorax avenae subsp. citrulli
SOURCE: D. B. Langston
DISEASE: Bacterial leaf spot (Head rot)
HOST: Lettuce
Leaf with black, greasy spots that tend to be vein delimited. Lesions begin as small, angular, water-soaked lesions that coalesce, resulting in large necrotic areas.
Bacterial leaf spot (Head rot) | Lettuce
DISEASE: Bacterial leaf spot (Head rot)
HOST: Lettuce (Lactuca sativa)
PATHOGEN: Xanthomonas axonopodis pv. vitians
PATHOGEN SYNONYM: Xanthomonas campestris pv. vitians
SOURCE: A. Alvarez
DISEASE: Bacterial wilt
HOST: Cantaloupe
Cantaloupe field with severe destruction from bacterial wilt (left), less on right.
Bacterial wilt | Cantaloupe
DISEASE: Bacterial wilt
HOST: Cantaloupe (Cucumis melo var. cantalupensis)
PATHOGEN: Erwinia tracheiphila
SOURCE: L. Claflin
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: Corky root
HOST: Lettuce
Corky root causes a reduction in size of lettuce heads and root systems; susceptible cultivar (right) and resistant cultivar (left).
Corky root | Lettuce
DISEASE: Corky root
HOST: Lettuce (Lactuca sativa)
PATHOGEN: Sphingomonas suberifaciens
PATHOGEN SYNONYM: Rhizomonas suberifaciens
SOURCE: E. J. Ryder
DISEASE: Corky root
HOST: Lettuce
Close-up of root with malformed, corky appearance and longitudinal ridges of brown tissues.
Corky root | Lettuce
DISEASE: Corky root
HOST: Lettuce (Lactuca sativa)
PATHOGEN: Sphingomonas suberifaciens
PATHOGEN SYNONYM: Rhizomonas suberifaciens
SOURCE: A. van Bruggen