1. A. The General Seed Certification Requirements provided in this Part apply to all crops, and together with the following specific standards constitute the certified Sweet Potato seed standards.
2. B. Requests for exemptions to any requirement set forth in this Section shall be submitted to LDAF in writing. In the case that LDAF approves an exemption, the grower may be required to implement additional LDAF approved safeguards to insure the health and integrity of the certified plants or roots.
3. C. Breeder Seed Stock entering the certification program shall be sourced from an LDAF approved virus elimination program, maintained in tissue culture, and tested for known pathogens proven to be detrimental to the health of the seed stock.

4. D. Definitions. The following definitions apply to this Section only.

   1. Clean Plant Center—sweet potato plant propagation facility approved by state certifying agencies that provide micropropagated, virus-tested, and apparently pest-free nuclear plant stock.
   2. Field—a clearly defined contiguous area containing sweet potato production of the same variety throughout the area.
   3. Generation—age of material; generation number advances upon exposure to subsequent unprotected environments (growing seasons).
   4. LDAF—the Louisiana Department of Agriculture and Forestry.
   5. Mericlone—is a plant clonally propagated from a single apical meristem.
   6. Micropropagation—is the art and science of plant multiplication in-vitro. Sweet potato is most commonly micropropagated in tissue culture by aseptic transfer of stem segments containing one to three nodes placed in sterile medium to produce nuclear plants.
   7. Symptomatic Plant - a plant that exhibits an indication or symptom of a disease, mutation, pest, virus, or other problem that may affect sweet potato production.
   8. Vine cutting or Slip—a stem section of suitable length with at least 2 - 3 nodes for transplanting in the greenhouse or field.
   9. Virus-Tested—a plant that has been tested for the presence of viruses by grafting a sweet potato shoot to the Brazilian morning glory (Ipomoea setosa), by negative PCR assay for destructive sweet potato viruses, or by other standards established by the National Clean Plant Network - Sweet Potato.

5. E. Classes and sources of certified planting stock

   1. 1. Breeder Seed Stock is sweet potato propagation material identified and described by the breeder or developer and is entered into and maintained by a Clean Plant Center. This material is obtained through methods approved by LDAF.
   2. 2. Nuclear Plant is a plant derived from Breeder Seed Stock. It is virus-indexed, apparently free of other pests, and evaluated in field test for trueness-to-type. This material is maintained under strict isolation by Clean Plant Centers. Nuclear Plants may exist as in-vitro tissue culture plantlets, or plants grown in an approved greenhouse. LDAF inspections begin with the inspection of Nuclear Plants located at Clean Plant Centers.
   3. 3. G0 Plants are greenhouse plants produced by certified growers from Nuclear Plants. G0 plants may be used to produce G0 plants when located within a greenhouse unexposed to a field environment. When exposed to a field environment, G0 plants become G1 plants.
   4. 4. G1 Seed are produced from G0 and G1 plants. Vine cuttings may be taken repeatedly from this original G1 planting to establish subsequent G1 plantings. All subsequent cuttings must occur within the same year. Vines and roots produced during this first year in the field are designated as G1.
   5. 5. G2 Seed (second field generation) is established from G2 plants grown from G1 roots. Vine cuttings may be taken repeatedly from this original G2 planting to establish subsequent G2 plantings. All subsequent cuttings must occur within the same year. Vines and roots produced during this second year of field production are designated as G2.
   6. 6. G3 Seed (third field generation) is established from G3 plants grown from G2 roots. Vine cuttings may be taken repeatedly from this original G3 planting to establish subsequent G3 plantings. All subsequent cuttings must occur within the same year. Vines and roots produced during this third year of field production are designated as G3.

   7. 7. Certified Plant Cutting Designations

      1. a. G0 Cuttings—vine cuttings from G0 plants grown in a certified greenhouse.
      2. b. G1 Cuttings—vine cuttings from G1 plants that are established in the field from G0 cuttings which become G1 cuttings once they leave the greenhouse or from vine cuttings from G1 plants. G1 cuttings produce G1 roots.
      3. c. G2 Cuttings—vine cuttings from sprouts from bedded G1 roots or from vine cuttings from G2 plants. G2 cuttings produce G2 roots.
      4. d. G3 Cuttings—vine cuttings from sprouts from bedded G2 roots or from vine cuttings from G3 plants. G3 cuttings produce G3 roots.

6. F. Greenhouse Requirements

   1. 1. Greenhouses containing certified sweet potato plants or roots of any generation are subject to these requirements.
   2. 2. LDAF must approve greenhouses before Nuclear Plants are released to the grower for the production of G0 stock.
   3. 3. Grower shall provide a copy of the LDAF greenhouse inspection report to the Clean Plant Center before plants are released to the grower.

   4. 4. Greenhouses shall meet the following requirements:

      1. a. Greenhouses shall be sanitized or maintained free of all plants a minimum of six weeks prior to receiving plants at the beginning of the crop year.
      2. b. Greenhouses shall only contain nuclear stock or G0 plants that originated from nuclear stock; no other plants allowed in the greenhouse except for approved indicator plants.
      3. c. Entry points shall be double doors or single door with air curtain to prevent aphid, whitefly or other injurious pest entry, and designed to restrict entry by unauthorized personnel.
      4. d. A system for sanitizing hands and feet prior to entry into the growing areas of the greenhouse shall be maintained and proper signage relaying that information posted at entries.
      5. e. Yellow sticky traps shall be used in an amount to adequately monitor aphids, whiteflies and other injurious insects.
      6. f. Any openings such as vents, and windows shall be covered with insect-proof screens to prevent entry of aphids, whiteflies and other injurious insects.
      7. g. An integrated pest management program shall remain in place to control aphids, whiteflies and other injurious insects.
      8. h. Cutting tools shall be decontaminated on a regular basis and always decontaminated prior to being used between groups of plants.
      9. i. All growing media and containers must be new, or sanitized by a method approved by LDAF.

      10. j. Isolation

          1. i. No plants are allowed to grow within 10 feet of the greenhouse, except for turf grass used for stabilization of the soil. Weeds shall be controlled by grower.
          2. ii. The perimeter of the greenhouse shall be a minimum of 250 feet away from any non-certified sweet potatoes, greenhouses containing non-certified plants, sweet potato storage sheds, cull piles or other potential sources of sweet potato viruses. Upon written request of the grower, LDAF may allow an isolation distance of less than 250 feet.
          3. iii. Different varieties/cultivars shall be clearly identified and separated within the greenhouse.

   5. 5. Producer Inspections

      1. a. Producer shall inspect plants routinely. If symptomatic plants are found, they shall be removed and destroyed.
      2. b. The grower shall keep a log book documenting routine inspections and the variety and number of plants that were removed. The log book shall be made available to LDAF upon request.
      3. c. Grower shall inspect each greenhouse and its perimeter routinely to ensure that the greenhouse isolation requirements are being met.

   6. 6. LDAF Inspections

      1. a. LDAF will inspect certified greenhouses monthly and at other times as needed if problems are observed. If symptomatic plants are found during these inspections the grower shall rogue and dispose of these plants properly in order to maintain certification status.
      2. b. A unit of certification shall be the entire greenhouse and such unit cannot be subdivided for the purpose for certification.

   7. 7. Specific Greenhouse Requirements

      Maximum Tolerance Allowed
      Factor	Nuclear Plants	G0 Plants
      Bacterial Stem Rot (Erwinia chrysanthemi)*	0	0
      Black Rot (Ceratocystis fimbriata)*	0	0
      Scurf (Monilochaetes infuscans)*	0	0
      Root-Knot Nematode (Meloidogyne spp.)	0	0
      Feathery Mottle (sweet potato feathery mottle virus [SPFMV])*	0	0
      Russet Crack (a strain of SPFMV)*	0	0
      Internal Cork*	0	0
      Wilt (Fusarium oxysporum f. sp. batatas)*	0	0
      Sweetpotato Weevil (Cylas formicarius)	0	0
      Exotic or hazardous pests	0	0
      Variety mixture	0	0
      Off-types (mutations)	0	0

      *Plants or mini-roots exhibiting symptoms

7. G. Field Requirements

   1. 1. Individual certified fields shall only contain certified sweet potato plants. Upon written request of the grower, LDAF may allow non-certified G0 plants, that originated from nuclear stock, to be produced in certified fields.

   2. 2. Sweet potato seed shall not be eligible for certification if produced on land which:

      1. a. has produced sweet potatoes, received manure or sweet potato residue in the previous two years;
      2. b. is subject to drainage from fields in which sweet potatoes are currently growing or have been grown in the previous three years.
   3. 3. Production fields shall be a minimum of 750 feet from any non-certified sweet potato plants. LDAF may allow an isolation distance of less than 750 feet upon written request of the grower.
   4. 4. Different generations and varieties must be clearly identified and separated by a minimum of five feet clean and tilled break.
   5. 5. An LDAF approved program shall be in place to control perennial morning glory species and volunteer sweet potato plants.

   6. 6. Inspections

      1. a. Grower shall inspect fields weekly during the growing season and rogue any symptomatic plants found. LDAF shall be informed if any problems concerning certification requirements are found.
      2. b. LDAF will perform a minimum of one seed bed inspection to determine that quality plants are being produced and that plants are apparently free of injurious insects and harmful diseases. LDAF may perform additional seed bed inspections as required to confirm standards are being met.
      3. c. LDAF will perform a minimum of two inspections on each production field during the growing season. The first field inspection shall be made before vines have covered the ground so that symptomatic plants may be easily identified. The second inspection shall be made within two weeks prior to harvest or no earlier than ninety days after planting.
      4. d. The unit of certification for production is a field and cannot be subdivided for the purpose for certification.

   7. 7. Specific Field Plant Requirements (Vine inspection standard)

      Maximum Tolerance Allowed
      Factor*	G1 Plants	G2 Plants	G3 Plants
      Bacterial Stem Rot (Erwinia Chrysanthemi)	None	None	None
      Fusarium Wilt (Fusarium oxysporum f. sp. Batatas)	None	None	None
      Sweetpotato Weevil (Cylas Formicarius)	None	None	None
      Exotic or hazardous pests**	None	None	None
      Off-types (Mutations)	0.05%	0.05%	0.10%
      Variety or cultivar mixture	0.3%	0.5%	0.5%

      *If other severe factors are observed at time of inspection, rejection of all or a portion of a field may occur.

      **If sampled roots report presence of guava root-knot nematode (Meloidogyne enterolobii), the entire field will not be eligible for certification.

8. H. Seed Root Storage Requirements

   1. 1. The procedures for cleaning and sanitizing the structure where certified sweet potatoes are stored shall be in accordance with recommendations from the Louisiana Agricultural Experiment Station and approved by LDAF prior to any sweet potatoes being stored in the structure.
   2. 2. LDAF will perform one seed root storage inspection after harvest and before shipment. A minimum of twenty percent of sweet potatoes entered for certification shall be inspected during the storage inspection.
   3. 3. Sweet potatoes grown for certification shall be stored in new containers (crates, pallet boxes, etc.) or used containers that have been sanitized by a method approved by LDAF.
   4. 4. Certified seed roots shall be stored in a separate room from any non-certified roots, properly identified, separated by a minimum of two feet wide aisles between crates, and shall not be exposed to dust from grading and packing lines.

   5. 5. Specific Seed Root Tolerance Standards

      Maximum Tolerance Allowed
      Factor	G1, G2, G3 Seed Roots
      Surface rots (Fusarium spp.) & Soft Rots (Rhizopus spp.)	5.0%
      Bacterial Root Rot (Erwinia spp.)	None
      Black Rot (Ceratocystis fimbriata)	None
      Scurf (Monilochaetes infuscans)	None
      Streptomyces soil rot (Streptomyces ipomoeae)	0.5%
      Root-Knot Nematode (Meloidogyne spp.)	5.0%
      Guava Rooot-Knot Nematode (Meloidogyne enterolobii)	None
      Russet Crack (a strain of SPFMV)	None
      Wilt (Fusarium oxysporum f. sp. batatas)	None
      Internal Cork	None
      Wireworm (Condoderus spp.)	*
      Sweetpotato Weevil (Cylas formicarius)	None
      Exotic or hazardous pests	None
      Variety mixture	None
      Off-types (mutations)	0.50%

      *Severe damage shall be reason for rejection of certified status.

9. I. General Standards for Plants and Seed Roots

   1. 1. Plants and roots shall be apparently free of harmful diseases, injurious insects, and other harmful pests and true to variety characteristics.
   2. 2. All cuttings shall be made at least one inch above the surface of the soil or growing medium.
   3. 3. Cuttings shall be of satisfactory size for commercial planting, approximately 5”-12” in length.
   4. 4. Cuttings shall be loosely packed and shipped in boxes and shall not be shipped with non-certified plants.
   5. 5. Roots shall be the correct color, fresh, firm, and a minimum of one inch in diameter, four inches in length and 30 ounces maximum weight.

10. J. Tagging and Certificate Reporting System

    1. 1. An official, LDAF issued Bulk Retail Sale Certificate shall accompany each sale of certified sweet potato cuttings/slips. An official, LDAF issued certified tag shall accompany each sale of certified seed roots.
    2. 2. The grower shall send a copy of each completed Bulk Retail Sales Certificate to LDAF at the end of each quarter (March 31, June 30, September 30, December 31), or upon request by LDAF. Grower shall maintain a copy of each issued certificate for their records.

    3. 3. A complete record of certified sweet potato cuttings/slips and seed roots sales shall be maintained and made available to LDAF upon request. The record shall include, but not limited to:

       1. a. purchaser’s name,
       2. b. kind and variety/cultivar,
       3. c. class,
       4. d. date of shipment; and
       5. e. number of cuttings/slips or bushels shipped.

11. K. Quarantine of Certification Area

    1. 1. If sweetpotato weevil (Cylas formicarius) is found in any field, greenhouse, storage, packing shed, or other structure or area affiliated with the production of certified sweet potatoes plants or roots, or within 300 yards of any such structure or area, then the entire area and all structures affiliated with the certification process shall be immediately quarantined in accordance with the sweetpotato weevil quarantine regulations found in Subchapter C of Part XV of Title 7 of the Louisiana Administrative Code (LAC 7:XV.133 et seq.).
    2. 2. If any plant pest or disease subject to regulation or quarantine under Part II or Part III of Chapter 12 of Title 3 of the Louisiana Revised Statutes of 1950, (R.S. 3:1651 et seq.) that may affect sweet potato production is found in any field, greenhouse, storage or packing shed, other structure, or area affiliated with the production of certified sweet potatoes plants or roots, then the entire area and all structures affiliated with the certification process may be subject to quarantine in accordance with applicable law and regulations.
    3. 3. Any sweet potato plants or roots produced or stored in a field, greenhouse, storage shed, packing shed, or other structure located within an area quarantined as a result of the detection of sweetpotato weevil shall be ineligible for final certification.

Authority Note

AUTHORITY NOTE: Promulgated in accordance with R.S. 3:1433.

Historical Note

HISTORICAL NOTE: Promulgated by the Department of Agriculture, Seed Commission, LR 8:579 (November 1982), amended LR 9:202 (April 1983), amended by the Department of Agriculture and Forestry, Office of Agricultural and Environmental Sciences, Seed Commission, LR 12:825 (December 1986), LR 22:1210 (December 1996), LR 36:1220 (June 2010), repromulgated by the Department of Agriculture and Forestry, Office of Agricultural and Environmental Sciences, Agricultural Chemistry and Seed Commission, LR 39:2725 (October 2013), amended LR 40:755 (April 2014), LR 44:1855 (October 2018), LR 45:1168 (September 2019), repromulgated LR 45:1438 (October 2019), amended LR 51:1568 (October 2025), LR 52:347 (March 2026).