Common name: Ralstonia, brown rot of potato
Scientific name: Ralstonia solanacearum Race 3 biovar 2
Status in Hawaii: Not known to be present in Hawaii
Ralstonia solanacearum Race 3 biovar 2 is a soil and water borne bacterium that causes wilt diseases in plants including brown rot of potato, bacterial wilt of tomato and eggplant, and southern wilt of geranium.
- Ralstonia solanacearum Race 3 does not occur naturally in the US and poses a threat to the horticulture industry as well as agriculture, specifically potato and tomato crops.
- Geranium: lower leaves of plants may show chlorosis (yellowing), wilting, and browning.
- Cut stems show bacterial ooze.
- Eventual plant death.
- Definitive identification requires laboratory testing.
- Infected geranium cuttings
- There are five known races of R. solanacearum worldwide. Race 1 is endemic to the southeastern US affects tomato crops and related Solanaceae. 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. Thanks to early detection, the pathogen has been eradicated from U.S. greenhouses.
Best Management Practices
- The specific pathogen, R. solanacearum race 3 biovar 2, is not found in the United States. Prevention and early detection can protect from new incursions and establishment.
- Consider sourcing options and pest distribution when purchasing plants. If sourcing geranium from outside of the U.S., purchase from nurseries participating in the APHIS Geranium Off-Shore Certification Program.
- BOLO: Be on the lookout! Carefully inspect all geraniums for symptoms of the disease: yellowing, wilting, and browning of leaves progressing to plant death.
- Report any suspect pests to 643pest.org or by phone 643-PEST (7378).
Other Nursery Pests
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This material was made possible, in part, by a Cooperative Agreement from the United States Department of Agriculture’s Animal and Plant Health Inspection Service (APHIS). It may not necessarily express APHIS’ views.