Any marketing agreement or order shall be terminated if the director finds that fifty-one percent by numbers and fifty-one percent by volume of production of the affected producers within the affected area favor or assent to such termination. The director may ascertain without compliance with the provisions of RCW 15.65.050 through 15.65.130 whether such termination is so assented to or favored whenever twenty percent by numbers or twenty percent by volume of production of said producers file written application with him or her for such termination. No such termination shall become effective until the expiration of the marketing season then current.