(a) The Secretary shall terminate or suspend the operation of any and all of the provisions of this part whenever the Secretary finds that such provisions do not tend to effectuate the declared policy of the act.

(b) The Secretary shall terminate the provisions of this part whenever it is found by referendum or otherwise that such termination is favored by a majority of the growers: Provided, That such majority has during the current marketing season produced more than 50 percent of the volume of grapes which were produced within the production area for shipment in fresh form. Such termination shall become effective on the first day of December subsequent to the announcement thereof by the Secretary.

(c) The provisions of this part shall, in any event, terminate whenever the provisions of the act authorizing them cease to be in effect.