Any referendum conducted hereunder may be held on a statewide basis pursuant to rules and regulations adopted by the State Board of Agriculture and Industries for the holding of such referendum. All producers of wheat, corn, grain sorghum, and oats who shall be subject to any assessments levied hereunder shall be entitled to vote in the referendum. In such referendum, individuals so eligible for participation therein shall vote upon the question of whether there shall be levied an assessment for a period of five years in an amount set forth in the call for such referendum, which amount shall not exceed the limitations prescribed by this article.