Except as otherwise provided in Section 62303, the director shall appoint:
(a) A local advisory board, if a majority of the producers individually, or through any nonprofit agricultural cooperative marketing association which is authorized by its members to so petition, request the establishment of such board.
(b) A regional advisory board, if in each marketing area which is involved a majority of producers that supply such marketing areas individually, or through any nonprofit agricultural cooperative marketing association which is authorized by its members to so petition, requests that such a board be established.