LANSING, Mich. –- The U.S. Department of Agriculture has identified Ralstonia solanacearum race 3 biovar 2 (RS r3b2) in a symptomatic geranium plant in a commercial greenhouse in Michigan. RS r3b2 is a bacterial pathogen causing a wilt disease in geraniums and several important food crops, including potatoes, tomatoes, peppers and eggplants. It can be transmitted through contaminated soil, irrigation water, or equipment. Once an infection is present, there is no effective chemical control to manage the disease in the plants.
This incident was first identified by a vigilant Michigan grower who noticed unusual wilt symptoms on his geraniums and sent them for testing.
“Ensuring this issue is dealt with quickly and safely is crucial to protecting the state’s agriculture economy,” said Gary McDowell, Director, Michigan Department of Agriculture and Rural Development. “Thanks to the grower’s alertness, combined with MDARD’s and USDA’s collaborative response, we have helped avert the establishment of this devastating disease into U.S. agricultural production systems.”
“This is the first introduction of the pathogen in the U.S. since 2004, when this disease was detected and eradicated in 27 states, including 14 facilities in Michigan,” said Mike Philip, director of MDARD’s Pesticide and Plant Pest Management Division. “It’s important to note the bacterium does not pose a threat to public or animal health or to food safety.” MDARD’s Pesticide and Plant Pest Management Division oversees the department’s plant health programs and will lead Michigan’s efforts to rid the state of this disease.
The geranium that tested positive was a Fantasia ‘Pink Flare’ variety imported from a production facility in Guatemala. The USDA determined an additional 288 plant growers in 39 states received affected shipments from the Guatemalan facility, including 41 growers in Michigan. The affected businesses are being notified and will be working with state and federal officials to identify and safely dispose of infected plants.
“This incident is a serious threat to our industry,” said Geoff Hansen, executive director of the Michigan Greenhouse Growers Council. “The affected facilities must work aggressively with MDARD to contain and eliminate this disease.”
In 2018, the wholesale value of Michigan’s floriculture industry totaled $467 million, the third largest in the United States. Potatoes are Michigan’s second leading produce commodity, generating $182 million in farm gate sales each year, while Michigan-grown tomatoes are valued at $35 million annually.
