W. Va. Code R. § 61-39-45

Current through Register Vol. XLI, No. 50, December 13, 2024

Section 61-39-45 - Seed Potato (Solanum tuberosum) Certification Standards

45.1. Standards for Seed Potato Production

45.1.1. The general seed certification definitions and standards in this rule are basic and together with the following specific standards constitute the standards for seed potato certification.

45.1.2. Fees for seed certification are contained in section 38 of this rule.

45.2. Definitions Specific to Seed Potato Production.

45.2.1. "Seed Potato" means the vegetatively propagated tubers used for potato production rather than true botanical seed sexually produced from potato flowers.

45.2.2. "Seed Potato Stock" means seed potatoes intended for use as a planting source for certification that are identity preserved with a certification number and a North American Plant Health Certificate.

45.2.3. "Generation" means a classification scheme of seed potatoes based on the number of field production years completed.

45.2.4. "Limited Generation Seed" means seed potatoes grown for a specific maximum number of field production years.

45.2.5. "Bacterial Ring Rot" is a disease caused by the bacterium Clavibacter michiganensis ssp. sepedonicus.

45.2.6. "Blackleg" is a disease caused by the bacterium Pectobacterium atrosepticum or Pectobacterium carotovorum ssp. carotovorum.

45.2.7. "Corky Ring Spot (Spraing)" is a disease caused by tobacco rattle virus.

45.2.8. "Late Blight" is a disease caused by the fungus Phytophthora infestans

45.2.9. "Root-Knot Nematode" means the plant parasitic nematodes Meloidogyne hapla, Meloidogyne chitwoodii, and Meloidogyne incognita.

45.2.10. "Mosaic Virus" means Potato Virus Y (PVY) and all of its various strains, PVA and other viruses including severe forms of PVX.

45.2.11. "Potato Leaf Roll Virus (PLRV) is a virus primarily transmitted by the peach potato aphid which colonizes potato crops during July and August.

45.3. Seed Classification.

45.3.1. Limited Generation Classes.

45.3.1.1. Pre-Nuclear (PN) - In vitro plantlets and microtubers used for production in a protected environment.

45.3.1.2. Nuclear (N) - Minitubers produced in a protected environment utilizing Pre-Nuclear material as planting stocks.

45.3.1.3. Field Year 1 (FY1) - 1^st field production and meets FY1 tolerances.

45.3.1.4. Field Year 2 (FY2) - 2^nd field production and meets FY2 tolerances.

45.3.1.5. Field Year 3 (FY3) - 3^rd field production and meets FY3 tolerances.

45.3.1.6. Field Year 4 (FY4) - 4^th field production and meets FY4 tolerances.

45.3.1.7. Field Year 5 (FY5) - 5^th field production and meets FY5 tolerances.

45.3.1.8. Field Year 6 (FY6) - 6^th field production and meets FY6 tolerances.

45.3.1.9. Field Year 7 (FY7) - 7^th field production and meets FY7 tolerances.

45.3.2. Each generation of seed is derived from planting the previous generation. At planting, the seed stock that was planted is automatically moved down one generation. For example, FY1 becomes FY2, FY2 becomes FY3. Seed potato stocks have to meet tolerances for the generation in which they are classified, regardless of field year production.

45.4. Seed Stock Eligibility Requirements.

45.4.1. Limited generation seed stocks are eligible for certification for seven (7) field production years. FY7 seed stocks, the 7^th field production year, are not eligible for certification.

45.4.2. All seed stocks purchased by a farming operation from another farming operation and subsequently entered for certification shall be tagged unless the purchaser was a co-applicant for certification of that seed.

45.4.3. The eligibility of seed purchased for recertification must be verified by one of the following: Tags, Bulk Sale Certificates, or an Invoice from the seed. The invoice shall include the variety, pounds sold, generation of seed, and lot number.

45.4.4. Bacterial ring rot found in a seed lot of a seed farm shall be cause to remove the lot from certification. All fields on that seed farm planted with the same seed lot as the rejected field will also be refused certification. All other seed lots associated with or planted after the rejected lot shall not be eligible for recertification but are eligible for commercial planting if all other certification requirements are met.

45.5. Land Requirements.

45.5.1. A field is not eligible to produce certified seed potatoes if noncertified potatoes or potatoes proven to be Bacterial Ring Rot infected were grown in the field within one previous growing season.

45.5.2. A field must be farmed for 1 (one) year with a crop other than potatoes immediately following the growing season in which potatoes were disqualified for Bacterial Ring Rot.

45.6. Field Isolation Requirements

45.6.1. Potatoes entered for certification shall be planted at least 20 feet from potatoes not entered for certification.

45.6.1.1. Seed lots shall be separated from each other by at least one row left unplanted or planted to some other crop.

45.6.2. Potatoes entered for certification as two seed lots of the same variety in the same field and found not to have the proper separation shall be designated as a single seed lot with the latest generation designation of the two seed lots.

45.7. Field Inspection Requirements

45.7.1. At least two inspections shall be made for each field entered during the growing season, prior to harvest.

45.7.1.1. Seed potatoes shall not exceed the tolerances for the 1^st and 2^nd inspections.

Table 1 - Percentages Allowed For 1^st Inspection¹
Factor²	FY1	FY2	FY3	FY4	FY5	FY6/7
Varietal Mixture	0.00	0.00	0.02	0.10	0.25	0.50
Mosaic	0.00	0.00	0.50	1.00	1.50	2.00
Potato Leafroll	0.00	0.00	0.03	0.05	0.10	0.20
Blackleg³	0.00	0.10	0.50	1.00	2.00	⁴
PVX	0.00	0.50	2.00
Total Virus⁵						2.00

Table 2 - Percentages Allowed For 2^nd Inspection¹
Factor²	FY1	FY2	FY3	FY4	FY5	FY6/7
Varietal Mixture	0.00	0.00	0.01	0.05	0.10	0.20
Mosaic	0.00	0.00	0.25	0.50	0.75	1.00
Potato Leafroll	0.00	0.00	0.02	0.03	0.08	0.20
Blackleg³	0.00	0.10	0.50	1.00	2.00	⁴
Total Virus⁵						1.00

¹Field inspections of FY1 and FY2 seed lots are advisory and all factors are required to be rogued when found in order to maintain the tolerance of 0.00%.

²Some disease may be present in a seed potato lot and not exhibit symptom expression in plants or tubers at the time of a regular inspection

³Determination of Blackleg disease is based on a visual plant symptom of an inky black stem originating from the seed tuber. Visible Blackleg has no tolerance in Generations 5 and 6 and therefore is not a disqualification factor.

⁴Visible Blackleg will not be a disqualification factor in FY6 or FY7.

⁵Total is the combined percentage of potato leafroll, calico, mosaic, and all other viral, viroid, and phytoplasmas (including Candidatus Liberibacter).

45.7.2. Fields shall be considered ready for inspection at all times. Additional inspections may be made at the discretion of the inspector but will not be made in order to allow growers to rogue fields which will not pass inspection.

45.7.3. Seed lots that exceed the generation tolerance for a particular factor shall be downgraded to the next generation for which the seed lot does not exceed the tolerance.

45.7.4. Volunteers must be rogued from any field of FY1 and FY2 seed potatoes. FY3 through FY7 fields that show volunteer potato plants remain eligible for certification when the volunteer plants are not found in excess of 3% of the total plants in the field. Volunteer plants shall be considered as part of the field from the standpoint of all factors of inspection.

45.7.5. FY3 and FY4 fields downgraded but not disqualified at the time of either the regular 1^st or 2^nd inspection because of a rogueable viral or varietal mixture problem may be reinspected one time.

45.7.6. Any seed lot shall only be allowed one reinspection during the season.

45.7.7. Chemical Injury.

45.7.7.1. The inspector may withhold certification pending the outcome of the winter test plot growout or refuse certification on a field or portion of a field sprayed or contaminated with a chemical that causes seed-borne injury to seed potatoes.

45.7.7.2. Those portions of a field that show enough chemical injury to the potato foliage to interfere with the field inspection process shall be rejected from certification if the potatoes are stored.

45.7.7.3. Those portions of a field that do not show enough chemical injury to interfere with field inspections but still may be contaminated to the degree that seed-borne chemical injury may occur in the next crop, shall be harvested and stored separately from other potatoes in that seed lot.

45.7.7.4. Under the direction of an inspector, a separate winter test sample shall be collected and submitted from those potatoes with the possible chemical injury.

45.7.7.5. Certification will be withheld until winter test readings are completed.

45.7.8. Fields may shall be refused certification due to unsatisfactory appearance caused by weeds, poor growth, poor stand, disease, insect damage, and any other condition which prevents accurate inspection or creates doubt as to the identity of the variety.

45.7.9. The following are grounds for seed lot disqualification:

45.7.9.1. Seed lots or portions thereof may be disqualified for certification because of any condition that interferes with the inspection of the potato plants;

45.7.9.2. Bacterial Ring Rot and Root-Knot Nematode are zero tolerance factors. Any seed lot, regardless of generation, is automatically disqualified from certification when any of these factors are found at any time;

45.7.9.3. Evidence of failure to remove daughter tubers from rogued hills;

45.7.9.4. When Bacterial Ring Rot is found in a seed lot, all potatoes grown by that farming operation from that seed source shall be disqualified;

45.7.9.5. The presence of any new or exotic disease to the state of West Virginia;

45.7.9.6. Failure to list on an application all seed sources that were used to plant a particular seed lot; and

45.7.9.7. Failure to have potatoes graded, inspected, and tagged at shipping.

45.8. Post-Harvest Testing Requirements.

45.8.1. Each seed lot shall be post-harvest tested. Lots, or portions thereof, which are shipped prior to post-harvest testing will be certified based on the two (2) summer field inspections.

45.8.2. Only seed lots that have passed the equivalent of a 2^nd field inspection shall be eligible for post-harvest testing.

45.8.3. The number of single drop tubers to submit for winter testing, regardless of generation or testing format are for:

45.8.3.1. Lots representing one acre or more: 400 tubers;

45.8.3.2. Lots representing 0.5 - 0.9 acres: 200 tubers;

45.8.3.3. Lots representing 0.1 - 04 acres: 100 tubers; and

45.8.3.4. Lots representing less than 0.1 acres: 10% of tubers to a maximum of 100.

45.8.4. Seed lots are disqualified for certification if seed-borne chemical injury in excess of 5% is found during post-harvest testing.

45.8.5. Seed lots are not eligible for recertification if any of the following factors are found during post-harvest testing at a percentage greater than:

45.8.5.1. Potato Leafroll Virus of 0.8%; or

45.8.5.2. Mosaic of 1.0%.

45.9. Potato Virus X (PVX) Testing Requirements: All seed entered for certification in the FY1, FY2, and FY3 classes shall be laboratory tested for PVX.

45.10. Bacterial Ring Rot Testing Requirements.

45.10.1. A random sample of stems or tubers obtained from all seed lots FY2 or higher shall be laboratory tested for bacterial ring rot.

45.10.2. The required testing shall be completed prior to final certification.

45.10.3. The minimum sample size shall be 10% of stems or tubers to a maximum of 200 stems or tubers for seed lots 0.1 acres or less, and 400 stems or tubers for seed lots exceeding 0.1 acres.

45.11. Pre-nuclear Class Production Requirements.

45.11.1. Pre-nuclear Materials.

45.11.1.1. Pre-nuclear materials consist of in vitro propagative materials, e.g., tissue culture plantlets and micro-tubers, maintained under aseptic conditions.

45.11.1.2.In vitro propagative materials may originate from the following sources:

45.11.1.2.1. The introduction of any potato plant part, including stems and tubers, into in vitro culture using aseptic technique; or

45.11.1.2.2. Existing in vitro materials obtained from another recognized tissue culture facility.

45.11.2. Record Keeping.

45.11.2.1. Tissue culture facilities shall maintain records of the origin and date of acquisition of all pre-nuclear materials.

45.11.2.2. The tissue culture facility shall assign a unique identifying code to each individual clone that will be used to track its multiplication and test history. A new identification code shall be assigned to each clone or sub-clone when:

45.11.2.2.1 Plant materials are introduced into in vitro culture; or

45.11.2.2.2In vitro material is received from another recognized tissue culture facility.

45.11.3. Required Testing.

45.11.3.1. All testing of pre-nuclear material shall be performed by the WVDA or a laboratory approved by the WVDA.

45.11.3.2. Introductory testing is performed when plant materials are introduced into in vitro culture or when in vitro material is received from another recognized tissue culture facility.

45.11.3.3. A minimum of two plantlets for each clone shall be tested and found free from PVA, PVS, PVM, PVY, PVX, PLRV, PotLV, PMTV, TRV, PSTVd, Clavibacter michiganensis subsp. sepedonicus, Pectobacterium spp. Materials that test positive for any of these pathogens are ineligible for certification.

45.12. Nuclear Class Production Requirements.

45.12.1. Nuclear materials.

45.12.1.1. Nuclear materials are the progeny of pre-nuclear materials produced in a protected environment (e.g., greenhouse or growth chamber).

45.12.1.2. Approved Planting Stocks:

45.12.1.2.1. Nuclear materials shall be produced using pre-nuclear stocks meeting the requirements described in subsection 45.11 of this rule.

45.12.1.2.2. First generation nuclear class mini-tubers produced in the grower's own protected environment facility may be used as planting stocks with the prior approval of the WVDA.

45.12.1.3. No plants other than those listed on the Application for Certification may shall be present in the individual units of a protected environment being used for the production of nuclear class materials.

45.12.1.4. Nuclear materials shall be physically separated to maintain seed lot integrity and purity at all times. Nuclear seed lots that are comingled shall be combined, downgraded, or rejected, as appropriate, as outlined in subsection 45.7 of this rule.

45.12.2 Inspections.

45.12.2.1. Nuclear crops shall be entered for certification within 14 business days of the planting of the crop.

45.12.2.2. A minimum of two inspections shall be performed on each nuclear seed lot entered for certification.

45.12.3. Required Testing.

45.12.3.1. Nuclear crops shall test free of the following pathogens: PVA, PVY, PVX, PLRV, Clavibacter michiganensis subsp. sepedonicus, Pectobacterium spp.

45.12.3.2. Testing must be done on a representative sample consisting of 1% of the plants or tubers with a minimum of five plants or tubers sampled per lot.

45.12.3.3. Units or lots in greenhouse production found to be infected with any of the organisms indicated above shall be downgraded or rejected, as appropriate, as outlined in subsection 45.7 of this rule.

45.13. Storage Facility Requirements

45.13.1. Storage inspections may be conducted at any time on all storage facilities containing seed potatoes eligible for certification.

45.13.1.1. Seed potatoes shall be stored in sanitized storage areas after harvest and shall not be stored in the same storage facility with potatoes known to be infected with bacterial ring rot and root knot nematode.

45.13.1.2. Each lot of seed potatoes shall be harvested, graded, and stored separately in such a manner as to preclude intermixing.

45.13.1.3. Each lot of stored seed potatoes shall be clearly identified in a manner approved by the WVDA.

45.13.1.4. All containers shall be new for Nuclear and FY1. Containers for FY2, FY3, FY4, FY5, FY6, and FY7 shall be cleaned and sanitized if they have been previously contained potatoes.

45.13.1.5. Storage where sprout inhibitors were used in the previous season is not to be used to store certified seed potatoes.

45.14. Grade Requirements.

45.14.1. Blue Tag Seed Potatoes.

45.14.1.1. The Blue Tag is equivalent to U.S. No. 1 seed potato grade.

45.14.1.2. The Blue Tag will carry the information of producer's name, address, variety, certification number, seed class or other variations, and the crop date for which the tags were issued.

45.14.2. Green Tag Seed Potatoes.

45.14.2.1. The Green Tag is equivalent to U.S. No. 2 seed potato grade.

45.14.2.2. The Green Tag will carry the information of producer's name, address, variety, certification number, seed class or other variations, and the crop date for which the tags were issued.

W. Va. Code R. § 61-39-45