The following specific rules constitute the requirements and standards for classes and sources of blackberry certified stock:

1. (1)

   1. (A) Nuclear stock shall be derived from plants that have been:

      1. (i) Micropropagated;
      2. (ii) Indexed;
      3. (iii) Apparently free from other pests; and
      4. (iv) Evaluated in field tests for trueness-to-variety.
   2. (B) Nuclear stock may exist as in vitro tissue culture plantlets or potted plants in a screened greenhouse.
   3. (C) Sources of plants grown as nuclear stock must be approved by the State Plant Board;
2. (2) Foundation stock is produced from nuclear stock and grown in a greenhouse or screenhouse to exclude insects;

3. (3) Registered stock is produced from foundation stock in:

   1. (A) Greenhouse;
   2. (B) Screenhouse; or
   3. (C) Field; and

4. (4) Certified stock is produced from registered stock in:

   1. (A) Greenhouse;
   2. (B) Screenhouse; or
   3. (C) Field.