The term of office of each member and alternate member of the Board shall be for three years beginning on June 1 of the year when appointed and ending on May 31 three years later: Provided that, of the nine initial members and alternates from the combination of Districts 1, 2 and 3, one-third of such initial members and alternates shall serve only one year, one-third of such members and alternates shall serve only two years, and one-third of such members and alternates shall serve three years; and one-half of the initial members and alternates from Districts 4 and 7 shall serve only one year, and one-half of such initial members and alternates shall serve two years (determination of which of the initial members and their alternates shall serve for one, two, or three years shall be by lot). Members and alternate members shall serve in such capacity for the portion of the term of office for which they are selected and have qualified until their respective successors are selected, have qualified, and are appointed. The consecutive terms of office of grower, handler and public members and alternate members shall be limited to two 3-year terms, excluding any initial term lasting less than three years. The term of office of a member and alternate member for the same seat shall be the same. The term of office specified in this section will become effective for all members, including members whose terms are not expiring, upon the first nomination cycle following the effectiveness of the final rule establishing this new term of office. The Board, with the approval of the Secretary, may establish rules and regulations necessary and incidental to the administration of this section.