Wilting Disease Found in Two Missouri Greenhouses

Missouri Department of Agriculture officials have found the plant disease Ralstonia solanacearum (sola-nay-see-air-um) in two Missouri greenhouses.

Also known as bacterial or Southern wilt, this particular strain of R. solanacearum affects a variety of plants, as well as members of the nightshade family such as potatoes, tomatoes and peppers. It is easily spread via soil and water. The disease poses no harm to humans or animals.

Early wilting symptoms Photo courtesy of the Wisconsin Department of Agriculture, Trade and Consumer Protection

The department is working with the U.S. Department of Agriculture’s Animal and Plant Health Inspection Service to monitor the spread of the disease. While 34 locations are being monitored for the disease, two locations have been confirmed positive, and the infected plant stock is being destroyed. In addition, plant protection specialists are checking greenhouses throughout the state that may have received shipments of infected plants to prevent further spread. The greenhouses will be monitored for several weeks. If no signs of the disease appear, the stock will be released for sale.

USDA has determined that the bacterium arrived in the United States via contaminated geraniums imported from a nursery in Kenya. Although about 150 greenhouses received the suspected geraniums, only 20 instances of the disease have been confirmed, according to Mike Brown, state entomologist with the Missouri Department of Agriculture. Illinois, Indiana, Delaware, Georgia, Maryland, Michigan, Tennessee and Wisconsin have confirmed cases of R. solanacearum.

"Fortunately, at this time of year, all of the plants are confined to greenhouses, making it easier to control and eliminate the disease," Brown said. "Unfortunately, this is the beginning of the peak season for nurseries and greenhouses, and the threat of this disease has prevented many of them from conducting business."

Because the disease was detected early, the infected plants have not made their way into the retail market. Consumers should not worry about this disease when buying geraniums for spring planting, Brown said.

The disease has also caused a stir because it is cited on USDA’s list of biological agents because it poses a serious threat to potatoes and is foreign to the United States. However, the USDA has said there is no evidence the contamination was intentional.

R. solanacearum was last found in the United States in 1999 and was successfully eradicated.

For more information on Ralstonia solanacearum, call the Missouri Department of Agriculture at 573-751-5507 or visit http://www.aphis.usda.gov/ppq/ep/ralstonia/.

Missouri Department of Agriculture