7 CFR 201.70: Limitations of generations for certified seed.

The number of generations through which a variety may be multiplied shall be limited to that specified by the originating breeder or owner and shall not exceed two generations beyond the Foundation seed class with the following exceptions which may be made with the permission of the originating or sponsoring plant breeder, institution, or his designee:

(a) Recertification of the Certified class may be permitted when no Foundation or Registered seed is being maintained; or

(b) The production of an additional generation of the Certified class may be permitted on a 1-year basis only, when an emergency is declared by any official seed certifying agency stating that the Foundation and Registered seed supplies are not adequate to plant the needed Certified acreage of the variety. The additional generation of Certified seed to meet the emergency need is ineligible for recertification.