Except as otherwise provided by the director of agriculture or by firmly established trade customs and practices, commodities shall be sold as follows:
(A) Commodities in liquid form shall be sold by liquid measure or by weight;
(B) Commodities not in liquid form shall be sold only by weight, measure, or county, or a combination thereof;
(C) The method of sale of commodities shall provide accurate quantity information that enables the buyer to make price and quantity comparisons.