A proposed amendment to an existing wheat development program may be requested by petition to the Director by 5% of the affected producers from across the State or by a two-thirds majority vote of the wheat development board. If any amendment to an existing wheat development program is proposed, the Director shall hold a public hearing to consider the amendment. After the close of the public hearing, the Director and the wheat development board shall send copies of their findings to all parties of record appearing at the hearing. A referendum may be held on the amendment in accordance with Section 40 subject to the same voting requirements for adoption of the wheat development program as set forth in Section 30. When an amendment is approved by referendum, the Department shall file the amendment with the Secretary of State as provided in Section 5-65 of the Illinois Administrative Procedure Act.
     The Director, upon recommendation of the wheat development board, shall establish procedures necessary in the development and adoption of the proposed amendment to an existing wheat development program. The procedures shall be included in the rules of the Department required by Section 5-15 of the Illinois Administrative Procedure Act.