Ralstonia solanacearum, Race 3 Biovar 2 found in U.S.
Gail Ruhl and Karen Rane, Plant Disease Diagnosticians,
Dept. of Botany and Plant Pathology, Purdue University
January 16th. 2004 New Pest Response Guidelines
(Action Plan) (pdf file) and more information may be found at the APHIS web site on Ralstonia.
According to Dr. Richard L. Dunkle, Deputy Administrator,
Plant Protection and Quarantine, the Plant Protection and Quarantine
(PPQ) Center for Plant Health Science and Technology laboratory
in Beltsville, Maryland, confirmed Ralstonia solanacearum,
Race 3 Biovar 2, the pathogen that causes southern bacterial
wilt, in geraniums from a commercial greenhouse in New York State.
The disease was confirmed in rooted cuttings of the Americana
Coral variety on December 31, 2003, as well as in direct–ship
material of the Americana Bright Red variety on January 2, 2004.
The New York state greenhouse had received both varieties in
infected propagative material originating from the Goldsmith
Plants, Inc. facilities located in Guatemala. The rooted plants
were received via Glass Corners Greenhouse in Michigan, where
this pathogen was eradicated earlier in 2003. The New York State
greenhouse was not implicated earlier in 2003. As per the Pest
Alert by Dr. Margery Daughtrey, Long Island Horticultural Research & Extension
Center, at http://www.hort.cornell.edu/greenhouse/, "Weather
conditions would not ordinarily have allowed symptom expression,
but the crop had been grown for a while at an unusually elevated
temperature due to a malfunctioning vent. The grower reported
the suspicious symptoms to his NYS Ag & Markets horticultural
inspector, and the pathogen was promptly identified to genus
The APHIS announcement states that approximately
300-400 customers have already received geraniums of the suspect
varieties from Goldsmith’s facilities
in Guatemala this growing season and that APHIS, in cooperation with State
Departments of Agriculture (and the DNR in Indiana), are notifying customers
and assuring appropriate actions are taken to destroy suspect plants and disinfect
Race 3 Biovar 2, is cited on USDA Agricultural Bioterrorism Act
of 2002 Select Agents and Toxins List, as a serious pathogen
of potatoes, tomatoes, and other solanaceous plants. However,
the present outbreak (similar to the 2003 occurrence) is due
to an unintentional introduction of the pathogen during the routine
and normal importation of geranium cuttings from Guatemala.
is important that growers do not move or discard any
cuttings of the suspect Goldsmith cultivars (rooted or unrooted)
until they have been contacted by USDA APHIS or state regulatory
officials. Movement of these plants from bench to bench or between
greenhouses will increase the chances of spreading the bacterial
pathogen and could result in greater losses. Special protocols
are required for disposal of infected plants to make sure the
bacterium is not introduced to the environment.
There has been no formal announcement of the 2004
USDA Action Plan for Ralstonia
solanacearum in geraniums. Special survey, sanitation, destruction
and disposal protocols will be forthcoming.
For excellent photographs of the symptoms of southern
bacterial wilt in geranium and other hosts check out the
USDA APHIS PPQ website.
Excellent photographs of geranium wilt symptoms
may also be viewed at http://www.floricultureinfo.com/ in
an article titled Pictorial Guide to Geranium Wilt Disorders by
Dr. Brain E. Whipker; Dept. of Hort Sciences, NC State University.
You can view this article by choosing "Ralstonia Information
- January 2004."
The Purdue Plant and Pest Diagnostic Laboratory
is fully equipped to identify and help you manage geranium disease
problems. If you have any questions, please contact Dr. Karen
Rane (765-494-5821), Gail Ruhl (765-494-4641) or Dr. Allen Hammer
The information given herein
is supplied with the understanding that no discrimination is
intended and no endorsement by the Purdue University Cooperative
Extension Service is implied. Any person using products listed
assumes full responsibility for their use in accordance with
current direction of the manufacturer. Purdue University is
an equal opportunity/equal access institution.
Information listed is valid
only for the state of Indiana.