Seed or Plant Considerations

Planting material should be obtained from producers that are certified by the appropriate association for the production and sale of clean sweetpotato planting material, including sweetpotato slips and seed roots. Protocols that producers follow for the production of clean sweetpotato slips include those that will minimize or prevent the introduction of pathogens. For example, practices include minimizing the movement of soil within and between greenhouses, utilizing clean knives when cutting planting material, and making cuts above the soil line to prevent the wound from encountering soil-borne pathogens. By purchasing planting material from certified producers, there is assurance that the purchased material will be true-to-type, high quality, and most importantly, disease and pest-free (Jennings, et al., 2019). Thus, the planting material that is transplanted into the field will have the best chance of producing greater yields of high-quality storage roots for later sale and prevent the introduction of unwanted pathogens and pests.

Below is a list of certified clean seed distributors, the certifying organization and/or organization that sets production guidelines, and any additional information for each state associated with the SweetARMOR project.

North Carolina

Certifying Association: NC Crop Improvement Association (NCCIA)

• Certifies Clean Seed Producers.
• Certifies that planting material received by the Clean Seed Producers is free of disease and pests.

Certified Clean Seed Producers:

Adapted from the list provided by the NCCIA. If interested in contacting a certified clean seed producer in the list below, click here.

• Barnes Farming (Spring Hope, NC)
• Burch Equipment LLC (Faison, NC)
• Edwards Family Farms (Whitakers, NC)
• H&D Farms, INC. (Autryville, NC)
• Ham Farms & Produce Company (Snow Hill, NC)
• Hill Farms, INC. (Kinston, NC)
• Jones Family Farms (Bailey, NC)
• Leggett Farming Partnership (Nashville, NC)
• Pierce, Danny (Princeton, NC)
• Robert & Wade Glover Farms INC. (Bailey, NC)
• Scott Farms (Lucama, NC)
• Strickland Farms, Clay (Spring Hope, NC)
• Sullivan Farms, INC. (Lucama, NC)
• TNT Family Farms, INC. (Spring Hope, NC)
• Vick Family Farms Partnership (Wilson, NC)
• Williams & Sons, Hershel (Autryville, NC)

The Micropropagation Center and Repository Unit (MPRU) located on the campus of NC State University maintains plants in tissue culture to reduce the occurrence of mutations and further tests for the presence of viruses (Jennings, et al., 2019). New planting stocks obtained each year by the NC Certified Sweetpotato Seed Producers are previously tested by the MPRU for the presence of disease. Before NC Certified Sweetpotato Seed Producers obtain the planting stock, the NCCIA further inspects planting material to further minimize the introduction of planting material that may have pest or disease incidence (Jennings, et al., 2019). The MPRU is a part of The National Clean Plant Network for Sweetpotatoes (NCPN-Sweetpotatoes).

Click here to visit The National Clean Plant Network for Sweetpotatoes (NCPN-Sweetpotatoes) webpage.

Click here to visit the North Carolina-specific page under NCPN-Sweetpotatoes.

Louisiana

Seed Production Guidelines Set By: Louisiana Department of Agriculture & Forestry

Like North Carolina State University’s MPRU, the Louisiana State University (LSU) AgCenter’s Sweet Potato Research Station has the Sweet Potato Foundation Seed Program. The Sweet Potato Foundation Seed Program serves as the primary program for the maintenance of nuclear stocks in tissue culture and further, the propagation of clean plant materials for distribution to sweetpotato producers (LSU AgCenter, 2022). Additionally, the Mission and Foundation Seed Program serves as the primary program for virus testing and virus elimination in maintained and distributed clean plant materials (LSU AgCenter, 2022). The Sweet Potato Foundation Seed Program is also a part of The National Clean Plant Network for Sweetpotatoes (NCPN-Sweetpotatoes).

The system involving the movement of clean planting material from the Sweet Potato Foundation Seed Program directly to sweetpotato growers is unique to the Louisiana sweetpotato industry. Other states, like North Carolina and Mississippi, do not have this direct movement of sweetpotato planting material. Rather, there exists a mediary between the program associated with The Clean Plant Network for Sweetpotatoes and sweetpotato producers. The mediaries are often a group of growers that have been certified by an appropriate state specific organization or association as Certified Sweetpotato Seed (or Plant) Producers. The Certified Sweetpotato Seed Producers serve as the main distributers of certified clean (i.e. disease and pest free) planting material to (noncertified) sweetpotato growers throughout their respective state.

Click here to visit The National Clean Plant Network for Sweetpotatoes (NCPN-Sweetpotatoes) webpage.

Click here to visit the Louisiana-specific page under NCPN-Sweetpotatoes.

Mississippi

Certifying Association: Mississippi Crop Improvement Association

• Certifies Clean Seed Producers.
• Certifies that planting material received by the Clean Seed Producers is free of disease and pests.

Certified Clean Seed Producers:

If interested in contacting a certified clean seed producer in the list below, click here.

• Alexander Farms, LLC. (Vardaman, MS)
• E3 Partnership (Woodland, MS)
• Flying Tater Farms

Like North Carolina and Louisiana, Mississippi has the Foundation Sweetpotato Program operated by the Mississippi Agricultural and Forestry Experiment Station. The Foundation Sweetpotato Program maintains a foundation greenhouse, ensures the propagation of clean plant material, and maintains tissue culture stock that is virus-free and vigorously virus-tested (NCPN, 2022). Further, the program ensures that maintained clean planting material is disseminated to certified seed producers in Mississippi (NCPN, 2022). The Foundation Sweetpotato Program is also a part of The National Clean Plant Network for Sweetpotatoes (NCPN-Sweetpotatoes).

Click here to visit The National Clean Plant Network for Sweetpotatoes (NCPN-Sweetpotatoes) webpage.

Click here to visit the Mississippi-specific page under NCPN-Sweetpotatoes.

California

Like North Carolina, Louisiana, and Mississippi, California has Foundation Plant Services for the purpose of maintaining and distributing clean, disease-free planting material to sweet potato producers in California. However, only sweet potato producers that are current members of The Sweetpotato Council of California will receive clean plants, not roots, from Foundation Plant Services. Like the previously described programs, sweetpotato plants are maintained in greenhouses, with the mother plants having derived from tissue culture stock that is disease-free and has been rigorously tested for viruses. In addition to the direct distribution of clean plants from Foundation Plant Services, there are currently three seed growers that will purchase from Foundation Plant Services to ramp up seed production for other growers to purchase. Of note, once plants leave the Foundation Plant Services, as is the case of roots produced by the three aforementioned seed growers, there are no assurances that the sweet potato plants are clean. Unlike other programs described above, there is not a certification program for clean seed production in California. Foundation Plant Services is also a part of The National Clean Plant Network for Sweetpotatoes (NCPN-Sweetpotatoes).

Click here to visit The National Clean Plant Network for Sweetpotatoes (NCPN-Sweetpotatoes) webpage.

Click here to visit the California-specific page under NCPN-Sweetpotatoes.

South Carolina

South Carolina does not maintain a certifying organization for clean seed producers and does not maintain a program within the realm of The National Clean Plant Network for Sweetpotatoes for the maintenance and distribution of clean seed to certified seed producers and noncertified sweetpotato growers.