After publication of his or her final decision, the director shall ascertain (either by written agreement in accordance with subsection (1) of this section or by referendum in accordance with subsection (2) of this section) whether the above specified percentages of producers and/or handlers assent to or approve any proposed order, amendment, or termination, and for such purpose:

(1) The director may ascertain whether assent or approval by the percentages specified in RCW 15.65.140, 15.65.150 or 15.65.190 (whichever is applicable) have been complied with by written agreement, and the requirements of assent or approval shall, in such case, be held to be complied with, if of the total number of affected producers or affected handlers within the affected area and the total volume of production of the affected commodity or product thereof, the percentages evidencing assent or approval are equal to or in excess of the percentages specified in said sections; or

(2) The director may conduct a referendum among producers within the affected area and the requirements of assent or approval shall be held to be complied with if of the total number of such producers and the total volume of production represented in such referendum the percentage assenting to or favoring is equal to or in excess of the percentage specified in RCW 15.65.140, 15.65.150 or 15.65.190 (whichever is applicable) as now or hereafter amended: PROVIDED, That thirty percent of the affected producers within the affected area producing thirty percent by volume of the affected commodity have been represented in a referendum to determine assent or approval of the issuance of a marketing order: PROVIDED FURTHER, That a marketing order shall not become effective when the provisions of subsection (3) of this section are used unless sixty-five percent by number of the affected producers within the affected area producing fifty-one percent by volume of the affected commodity or fifty-one percent by number of such affected producers producing sixty-five percent by volume of the affected commodity approve such marketing order;

(3) The director shall consider the assent or dissent or the approval or disapproval of any cooperative marketing association authorized by its producer members either by a majority vote of those voting thereon or by its articles of incorporation or by its bylaws or by any marketing or other agreement to market the affected commodity for such members or to act for them in any such referendum as being the assent or dissent or the approval or disapproval of the producers who are members of or stockholders in or under contract with such cooperative association of producers: PROVIDED, That the association shall first determine that a majority of its affected producers authorizes its action concerning the specific marketing order.