2025 - Your Commission at Work

YOUR RESEARCH COMMITTEE AT WORK

TITLE: Guava Root-Knot Nematode(GRKN) Mitigation (CountyActivities)

LEADER(S): C.D. Monks and Thomas Batts

IMPACT STATEMENT

We appreciate the dedication and support of the NC Sweetpotato Commission towards our team’s efforts to address this critical issue for sweetpotato producers and the entire industry. Short-term, positive impacts have been realized by improving educational resources surrounding best management, production, and packinghouse practices. This has been through published BMPs and educational materials that apply to workers and others in the industry. Rotational studies that require multiple years of study are well underway and will shed more light on which crops have the potential to help growers manage the GRKN.

TITLE: Preliminary Data for Hot Water Treatment of Sweetpotato Seed Roots and Cut Slips for Control of GRKN

LEADER(S): Adrienne M. Gorny (Lead)

IMPACT STATEMENT

The guava root-knot nematode (GRKN, Meloidogyne enterolobii) has emerged as the most important pathogen affecting species of sweetpotato, posing a threat to a multimillion-dollar industry in the United States. This nematode is a polyphagous species that attacks a wide range of field crops, fruits, vegetables, ornamentals, and weeds. GRKN is highly virulent, and there are no known sources of genetic resistance. Furthermore, the resistance that is effective for other species of root-knot nematode is overcome by this nematode. Upon infecting sweetpotato, it leads to large knots and galls along the storage root, resulting in an unmarketable crop. Furthermore, sweetpotato seed roots and planting slips can serve as a vector for moving the nematode; if GRKN infection is present in these materials (either through galls in the seed roots, or infested soil, or infected roots on cut slips). There is currently a lack of a suitable and reliable method to eradicate GRKN that may potentially be present in planting materials. Due to the quarantine nature of this pathogen and zero tolerances for the nematode in seed stocks, our goal is to research whether hot water treatment can completely kill or render inviable all GRKN life stages that may be present in the root (egg, juveniles, and adults). The use of hot water to treat plant parts (thermotherapy) has been used in other agricultural sectors, including vegetable seeds, strawberry transplants, and some ornamental crops.

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