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 (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: Carnation
Carnation stem with cankers and cracks. Yellow sticky bacterial slime is often seen.
Bacterial wilt | Carnation
DISEASE: Bacterial wilt
HOST: Carnation (Dianthus caryophyllus)
PATHOGEN: Burkholderia caryophylli
PATHOGEN SYNONYM: Pseudomonas caryophylli
SOURCE: E. Hellmers, Royal Veterinary & Agricultural University
DISEASE: Bacterial wilt
HOST: Carnation
Severely diseased and withered plants.
Bacterial wilt | Carnation
DISEASE: Bacterial wilt
HOST: Carnation (Dianthus caryophyllus)
PATHOGEN: Burkholderia caryophylli
PATHOGEN SYNONYM: Pseudomonas caryophylli
SOURCE: T. Saito, M. Goto
DISEASE: Bacterial wilt
HOST: Carnation
Sliced stem with discolored vascular bundles.
Bacterial wilt | Carnation
DISEASE: Bacterial wilt
HOST: Carnation (Dianthus caryophyllus)
PATHOGEN: Burkholderia caryophylli
PATHOGEN SYNONYM: Pseudomonas caryophylli
SOURCE: T. Saito, M. Goto
DISEASE: Bacterial wilt
HOST: Carnation
Systemic infection caused cracking and necrosis of the stem.
Bacterial wilt | Carnation
DISEASE: Bacterial wilt
HOST: Carnation (Dianthus caryophyllus)
PATHOGEN: Burkholderia caryophylli
PATHOGEN SYNONYM: Pseudomonas caryophylli
SOURCE: R. Raabe
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