In cases of serious shortages of seed stock, second generation seed may be accepted for certification as Foundation hybrids, with the specific approval of the Pennsylvania Agriculture Experiment Station. The second generation seed may be produced by one of the following methods:

1. (1) As the result of hand-pollination among pollen parent plants in an isolated plot or field in which a certified commercial hybrid is being produced.
2. (2) As a result of hand-pollination among pollen parent plants in a breeding nursery.
3. (3) From an isolated field devoted to increase single crosses which were properly inspected and approved.