Potato brown rot bacteria found in Michigan greenhouse

The United States Department of Agriculture’s Animal and Plant Health Inspection Service (APHIS) 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 can cause a wilt disease in several important agricultural crops, including potatoes, tomatoes, peppers and eggplant. This is the first confirmed case of RSr3b2 in a U.S. greenhouse since 2004.

APHIS has taken immediate action to contain and eradicate the disease from the Michigan facility. We confirmed that the infected plants came from a greenhouse in Guatemala. The importer immediately stopped shipments of geranium plants to the U.S. upon confirmation of the detection and has voluntarily agreed to destroy all shipments that were pending export or in route to the U.S. They also provided a list of 288 greenhouses in 39 states that received geranium cuttings from the Guatemala facility.

Federal and state agriculture officials are currently visiting the 288 greenhouse locations. They will inspect, isolate and destroy all Fantasia ‘Pink Flare’ geranium plants and co-mingled and exposed host and non-host plants. They will also isolate, sample and destroy other geranium varieties and co-mingled 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 our sanitation protocol to clear the facility of the pathogen.