Bacterial Wilt
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Scientific Name:
Ralstonia solanacearum race 3 biovar 2
(formerly Pseudomonas solanacearum)
Common
Names: bacterial wilt, Southern bacterial wilt,
Southern wilt, brown rot
Known
Hosts:
Geranium (Pelargonium spp.)
Solanaceous crop plants including potato (Solanum
tuberosum), eggplant (Solanum melongena),
and tomato (Lycopersicon esculentum).
Solanaceous weeds may act as host reservoirs including
climbing nightshade (Solanum dulcamara) and
stinging nettle (Urtica dioica).
| Symptoms |
| Geranium
|
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Wilting begins with lower
leaves and petioles and works its way up the plant.
(Figure 1) |
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Wilted leaves with chlorotic,
wedge-shaped areas or chlorotic and/or necrotic
leaf margins. No leaf spots are evident. (Figure
2) |
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Eventually entire plant collapses
on the medium (Figure 3) |
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White runny ooze from cut
stems (Figure 4) |
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| Potato |
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Wilting of the leaves at the
end of the day with recovery at night. Plant will
eventually fail to recover and die. (Figure 5) |
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Brown staining of vascular
ring. Pus may exude from the ring when the tuber
is squeezed. (Figures 6 and 7) |
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Pale ooze may exude from eyes
and heel end of potato. Soil will adhere to the
oozing eyes. (Figure 8) |
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Cross-section of a stem placed in water will exude milky white strands |
Similar disease or symptoms:
Geranium
Bacterial blight caused by Xanthomonas campestris
pv. pelargonii causes leaf spots in addition
to wilting.
This article on Ohio Floriculture Online discusses the
differences in the two diseases.
http://floriculture.osu.edu/archive/apr02/Bacterial.html
Wilting can have a variety
of causes including root rot, high fertilizer salts
or water stress.
Potato
Wilting of potato leaves can
also be due to water stress.
Brown staining of vascular
ring is also a symptom of ring rot caused by Clavibacter
michiganensis subsp. sepedonicus. See
Department for Environment, Food, & Rural Affairs,
UK webpage for a comparison. http://www.defra.gov.uk/planth/pestnote/ringrot.pdf
Fact
sheets and references:
USDA/APHIS/PPQ Ralstonia web page
http://www.aphis.usda.gov/plant_health/plant_pest_info/ralstonia/index.shtml
UMass Extension Floriculture Team
http://www.umass.edu/umext/floriculture/fact_sheets/pest_management/south_bact_wlt.html
USDA National Agriculture Library
Species Profile for Southern Bacterial Wilt
http://www.invasivespeciesinfo.gov/microbes/bacterialwilt.shtml
NAPPO Phytosanitary Alert System
http://www.pestalert.org/Detail.CFM?recordID=70
EPPO Data Sheet on Quarantine Pests:
Ralstonia solanacearum
http://www.eppo.org/QUARANTINE/bacteria/Ralstonia_solanacearum/PSDMSO_ds.pdf
Canadian Food Inspection Agency
http://www.inspection.gc.ca/english/sci/surv/data/ralsole.shtml
Bacterial wilt of potatoes,Department
of Agriculture, Western Australia, Farmnote 84/88
http://www.agric.wa.gov.au/content/PW/PH/DIS/VEG/FN084_1988.HTM
International Potato Center (CIP),
Peru: Information on bacterial wilt symptoms, research,
and control
http://www.cipotato.org/potato/pests_diseases/bacterial_wilt/symptoms.asp
last reviewed February 25, 2008 |
