After final recommendation of the adoption, amendment, or termination of a marketing order, the Commission shall determine by referendum whether the affected producers assent to the proposed action. The Commission shall conduct the referendum within forty-five days after the issuance of the final order. The affected producers shall be deemed to have assented to the proposal if either of the following conditions are met:
(1) If sixty-six and two-thirds percent or more by number of those voting representing fifty-one percent or more of the volume of the affected commodity produced by those voting assent to the proposal.
(2) If fifty-one percent or more by number of those voting representing sixty-six and two-thirds percent or more of the volume of the affected commodity produced by those voting assent to the proposal.