The wheat commission shall be composed of five members who: (1) Are landowning residents of South Dakota; (2) Are at least twenty - five years of age and residents of South Dakota; (3) Have been actually engaged in growing wheat in this state for a period of at least five years; (4) Derive a substantial portion of their income from growing wheat; and (5) Are participating growers. Source: SL 1961, ch 11 , § 4 (2); SL 1993, ch 302 , § 4.