(1) Commencing July 1, 1988, there is hereby levied an excise tax of one cent per bushel upon all wheat sold through commercial channels in the State of Nebraska. Commencing July 1, 1989, the board may levy an excise tax of not to exceed one and one-fourth cents per bushel upon all wheat sold through commercial channels in the State of Nebraska. Commencing July 1, 1990, the board may levy an excise tax of not to exceed one and one-half cents per bushel upon all wheat sold through commercial channels in the State of Nebraska. The tax shall be levied and imposed on the grower at the time of sale or delivery and shall be collected by the first purchaser. Under the Nebraska Wheat Resources Act, no wheat shall be subject to the tax more than once.
(2) The board shall have the power to reduce the excise tax for such period as it shall deem justified, but not less than one year, whenever it shall determine that the excise tax provided by this section is yielding more than is required to carry out the intent and purposes of the Nebraska Wheat Resources Act. If the board, after reducing such excise tax, finds that sufficient revenue is not being produced by such excise tax, it may restore in full or in part such excise tax not to exceed the amount per bushel authorized in subsection
(1) of this section.