After the institution of any marketing program, the program shall be terminated if there is filed with the director a petition for its termination which is signed by not less than 40 percent of the producers of the commodity in the proration zone that produced not less than 40 percent of the commodity affected that was produced within the proration zone during the last preceding season.
The signatures of the producers upon the petition shall be those of the producers whose names appear on the list which was used at the institution of the program or on any corrected list which the director has had prepared during the existence of the marketing program, or their successors in interest.