A new pest detected in two farm fields in Darlington County has resulted in a quarantine of South Carolina sweet potatoes by Louisiana and Mississippi.
The guava root-knot nematode (Meloidogyne enterolobii) is considered to be the most damaging root-knot nematode in the world “because of its wide host range, aggressiveness, and ability to overcome the resistance that has been developed against root-knot nematodes in many crops.”
Guava root-knot nematode was detected in the Darlington County fields during a routine survey by Clemson University’s Department of Plant Industry (DPI) in September 2017 and confirmed by the U.S. Department of Agriculture in January 2018.
Louisiana has prohibited the import of fresh market sweet potatoes and sweet potato seeds and slips from South Carolina. The state also is blocking the entrance of soil from South Carolina. In addition, all South Carolina commercial planting and harvesting equipment entering Louisiana must be accompanied by a DPI-issued certificate of inspection. All South Carolina nursery stock entering the state must have a soil sample and certificate from DPI indicating the sample is free of the nematode.
According to newsstand.clemson.edu, Mississippi has applied the same restrictions, but specific to Darlington County rather than state-wide.
Because the quarantine could expand to other states, Clemson DPI has created a webpage to keep growers up to date with the latest information. It’s also possible, pending survey results, that South Carolina will enact its own quarantine later this year. Quarantine updates will be posted to http://clemson.edu/regulatory/grkn.