In the event the required number of catfish producers approve by a referendum as provided in this article the levying of an assessment upon the sale of catfish feed for a promotional program, the Commissioner of Agriculture and Industries shall within 30 days, notify in writing every person licensed to sell or distribute catfish feed under authority of Section 2-21-19, that on or after the date designated in the notice, which shall be not less than 30 nor more than 60 days after the mailing of the notice by the Commissioner of Agriculture and Industries, the amount of the assessment shall be levied on the sale of catfish feed by all distributors of catfish feed or by their agents or representatives from the purchase price paid to the seller of the feed where the feed is purchased within the state. All assessments so levied shall be remitted to the Commissioner of Agriculture and Industries not later than the last day of January, April, July, and October of each year. The books and records of all such distributors of catfish feed shall at all times during regular business hours be open for inspection by the Commissioner of Agriculture and Industries or his or her duly authorized representatives or agents for the purpose of ascertaining the accuracy of the amounts remitted as required by this section. The Commissioner of Agriculture and Industries shall deduct from all sums remitted to him or her under this section, to defray the expense incident to collection and administration of this article, an amount to be set by the Board of Agriculture and Industries, but the amount shall not exceed three percent of the sum remitted. All amounts so deducted by the commissioner shall be paid into the State Treasury to the credit of the Agricultural Fund.