No farm equipment manufacturer shall:

(1) Coerce, or attempt to coerce, any farm equipment dealer to accept delivery of any farm equipment, parts or accessories therefor, which such farm equipment dealer has not voluntarily ordered;

(2) To condition or attempt to condition the sale of any farm equipment on a requirement that the farm equipment dealer also purchase any other goods or services but nothing contained in sections 407.838 to 407.848 shall prevent the farm equipment manufacturer from requiring the dealer to purchase all parts reasonably necessary to maintain the quality of operation in the field of any farm equipment used in the trade area;

(3) To coerce or attempt to coerce any farm equipment dealer into a refusal to purchase the farm equipment manufactured by another farm equipment manufacturer;

(4) To discriminate in the prices charged for farm equipment of like grade and quality sold by the farm equipment manufacturer to similarly situated farm equipment dealers, but nothing contained in sections 407.838 to 407.848 shall prevent differentials which make only due allowance for difference in the cost of manufacture, sale or delivery resulting from the differing methods or quantities in which such farm equipment is sold or delivered, by the farm equipment manufacturer.