South Carolina Code of Regulations
Chapter 27 - CLEMSON UNIVERSITY STATE LIVESTOCK-POULTRY HEALTH COMMISSION
Article 14 - SEED CERTIFICATION STANDARDS
Section 27-1001 - Sweet Potato Certification Standards

Universal Citation: SC Code Regs 27-1001

Current through Register Vol. 48, No. 3, March 22, 2024

I. Application of General Certification Standards

The General Certification Standards, Clemson University Regulation Regulation 27-190, are basic and applicable.

II. Land Requirements

A. Sweet potato stock eligible for certification must be produced:
1. On land which did not produce sweet potatoes during the past three years.

2. On land that did not receive manure or sweet potato residue during the past three years.

3. On land not subject to drainage water from fields that are now growing or have grown sweet potatoes during the last three years.

B. Sweet potato land shall be treated by approved methods for the control of wireworms and other soil insects where they are known to be a problem.

C. Plant Bed Requirements.
1. The plant bed must be located on well drained soil that has not produced sweet potatoes within the last three years unless disinfected by approved methods. The land must not be subject to drainage from barnyards or poultry yards or fields that are now or have grown sweet potatoes during the past three years.

2. Manure must not be used in the plant bed.

3. Seed sweet potatoes must be treated with an approved pesticide prior to planting.

III. Field Inspection

A. Plant Bed

One inspection shall be made when plants are nearly large enough to transplant.

B. Field

At least two field inspections shall be made, one shortly after transplanting of sprouts cut from the bed or vine cuttings. The final field inspection shall be performed at least 21 days after the first inspection and when diseases and varietal mixtures can be most easily detected.

IV. Field Standards

A.
1. Unit of certification.

A field or a portion of a field.

2. Isolation

All fields producing a class of certified seed potatoes shall be isolated from other sweet potato fields in such a manner as to prevent mechanical mixture.

3. Planting stock requirements
a. Certified sweet potatoes must be produced from either vine cuttings or from sprouts cut from the bed.

b. Sprouts must be cut approximately 1 inch above the soil surface, using a knife which has been disinfected.

B. Specific Requirements.

Maximum Permitted in Each Class

Factor

Foundation

Registered

Certified

Plant Bed

Blackrot ............

None

None

None

Wilt ................

None

None

None

Other Varieties .....

None

None

None

Scurf ...............

None

None

None

Field

Wilt ................

None

None

5 plants/acre

Viruses .............

None

None

10 plants/acre

* Other Varieties ...

None

None

None

* Five plants current mutations allowed.

V. Seed and Storage Standards

A. Seed
1. At least one storage inspection shall be made.

2. Seed stock must conform to the minimum standards for U.S. No. 1 grade except that minimum size shall not be less than 3 inches in length and 1 1/4 inches in diameter, and shall not exceed 10 inches in length and 3- 3/4 inches in diameter. [FN*]

3. Root standards

Maximum Permitted

Factor

Foundation

Registered

Certified

Common Storage Rots ...........

None

None

None

Blackrot ......................

None

None

None

Scurf .........................

None

None

0.1%

Wilt ..........................

None

None

0.1%

Internal Cork .................

5.0%

5.0%

5.0%

* Nematode ....................

None

None

0.5%

* Wireworm ....................

1.0%

2.0%

5.0%

Sweet Potato Weevil ...........

None

None

None

Other Varieties ...............

None

None

0.1%

* Tolerance applied to severely infected roots.

B. Storage
1. Storage potatoes grown for certification shall be stored in new containers, or used containers that have been disinfected with an approved pesticide.

2. Sweet potatoes must be stored in a facility that has been cleaned and disinfected.

3. Each unit of sweet potatoes that passes field inspection shall be stored according to production unit and treated separately and distinctly at the time of storage inspection. Each crate shall be marked or labeled to correspond with the field unit that passed inspection.

[FN*] Specific sizes of sweet potatoes in accordance with Federal Regulations shall be optional to grower and purchaser.

Disclaimer: These regulations may not be the most recent version. South Carolina may have more current or accurate information. We make no warranties or guarantees about the accuracy, completeness, or adequacy of the information contained on this site or the information linked to on the state site. Please check official sources.
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