Ralstonia solanacearum is a bacterium that causes wilt diseases in plants. It is not harmful to humans or animals. Worldwide, there are five known races of R. solanacearum. Races 2, 3, 4, and 5 are not known to occur in the United States. Race 1 is endemic to the southeastern United States where it can affect crops, such as tomato.
USDA considers R. solanacearum to be a select agent because the pathogen has the potential to pose a severe threat to plant health. If the race and biovar of R. solanacearum are confirmed to be race 3 biovar 2, crops may be impacted by diseases such as brown rot of potato, bacterial wilt of tomato and eggplant, and southern wilt of geranium.
In April 2020, APHIS confirmed the detection of R. solanacearum race 3 biovar 2 in a U.S. greenhouse that had purchased geranium cuttings from an offshore production facility. This is the first confirmed detection of this pathogen in a U.S. greenhouse since 2004. On June 11, 2020, APHIS and its State partners successfully completed actions to eliminate the pathogen from U.S. greenhouses.
In 2007, APHIS implemented a certification program for geraniums imported to the United States. The program requires specific clean-culture practices and regular testing in offshore greenhouses. Shipments must also be accompanied by a phytosanitary certificate with an additional declaration attesting that the geraniums have been tested and are free of R.
solanacearum race 3 biovar 2.
Plant Protection and Quarantine (PPQ) develops New Pest Response Guidelines (NPRGs) in preparation for potential future pest introductions.
This document is based on the best information available at the time of development and may not reflect the latest state of knowledge at the time the pest is detected. In addition, the PPQ response must be tailored to the specific circumstances of each pest introduction event, which cannot be predicted. Therefore, this document provides only general guidelines, to be used as a basis for developing a situation-specific response plan at the time a new pest is detected.
National Policy Manager