USDA confirms presence of Ralstonia in Michigan greenhouse
Photo: Mulderphoto, Adobe Stock

USDA confirms presence of Ralstonia in Michigan greenhouse

The bacterial plant pathogen affected geranium crops at an undisclosed operation.


AmericanHort issued the following statement on April 22, confirming the first case of Ralstonia in a U.S. greenhouse since 2004:

"The U.S. Department of Agriculture’s Animal and Plant Health Inspection Service (APHIS) announced on April 21 that it has confirmed the detection of Ralstonia solanacearum race 3 biovar 2 (RSr3b2) in a single variety of geranium plants located in a Michigan greenhouse. This particular type of Ralstonia, a bacterial plant pathogen, can cause a wilt disease in several important agricultural crops such as potatoes, tomatoes, peppers and eggplant. This is the first confirmed case of RSr3b2 in a U.S. greenhouse since 2004.

In a stakeholder notice, APHIS stated the agency has taken immediate action to contain and eradicate the disease from the Michigan facility. The infected plants, again of a single variety, came from a propagation greenhouse in Guatemala. The importer immediately stopped shipments of geranium plants to the United States upon confirmation of the detection. They also provided a list of 288 greenhouses in 39 states that received geranium cuttings from the Guatemala facility.

Under an APHIS response plan, Federal and State plant health officials are currently visiting the 288 greenhouse locations. They will inspect, isolate, and destroy all Fantasia ‘Pink Flare’ geranium plants and comingled and exposed host and non-host plants. They will also isolate, sample, and destroy other geranium varieties and comingled and exposed host and non-host plants if the other geraniums test positive for RSr3b2. After the plants are destroyed, the greenhouses will be cleaned according to sanitation protocols to clear the facility of the pathogen."