Upon certification of the commission, the secretary shall call meetings of producers and vintners in Mendocino County for the purpose of nominating and electing persons to the commission, or in the alternative, may conduct the elections by mail ballot. All producers and vintners on the secretary’s list shall be given written notice of the election meetings at least 15 days prior to the meeting date, or reasonable notice of elections by mail ballot and a reasonable time period in which to return ballots. In any election of producer and vintner members to the commission, only producers who are not also vintners may vote for producer members and alternate members, and only vintners may vote for vintner members and alternate members.