It is hereby further declared to be in the public interest and highly advantageous to the economy of the state that wheat, corn, grain sorghum, and oats producers be permitted by referendum as hereinafter provided to levy upon themselves an assessment, and to provide for the collection thereof for the financing or contributing toward the financing of a program of research, education, advertising and other methods designed to increase or promote the efficient and economical production, distribution and marketing as well as the increased use, consumption and sale of wheat, corn, grain sorghum, and oats and wheat, corn, grain sorghum, and oats products.