Further findings of Ralstonia solanacearum on Pelargonium in USA
Outbreaks of Ralstonia solanacearum race 3, biovar 2 (EPPO A2 quarantine pest) on Pelargonium have recently been reported from USA.
In 1999, R. solanacearum race 3 biovar 2 was detected in commercially grown Pelargonium in several glasshouses in New Jersey, New York, Pennsylvania, South Dakota and Wisconsin (see also EPPO RS 2002/166). Infected plants were subsequently destroyed and the glasshouses disinfected.
In February 2003, USDA confirmed the presence of R. solanacearum race 3 biovar 2 in Pelargonium in 4 glasshouses in Illinois, Indiana, Michigan and Wisconsin. The source of these infections was traced to imports of cuttings from Kenya (via rooting stations in Michigan and New Hampshire). Phytosanitary measures are being taken to eradicate the bacterium and prevent any further introduction: all infected plants have been destroyed and glasshouses disinfected, surveys are being done in USA to determine the extent of the disease in Pelargonium, and imports of Pelargonium from Kenya are prohibited until further notice.
Note: This is not the first time that outbreaks of R. solanacearum race 3, biovar 2 are reported on Pelargonium either from USA or from European countries (see EPPO RS 2001/106, 2001/124, 2002/115, 2002/166). In several instances, the sources of infection were imports of propagation material (e.g. cuttings) from Kenya or Guatemala. The risk of moving R. solanacearum race 3 biovar 2 on host plants other than Solanaceae, and in particular on Pelargonium, may need to be re-assessed.
APHIS-PPQ – Factsheet. March 2003. Detection of Ralstonia solanacearum race 3 biovar 2 in the United States.
APHIS Web site