The grower's price I understand to be the same with what is sometimes called the contract price, or the price at which a farmer contracts for a certain number of years to deliver a certain quantity of corn to a dealer.

我理解的种植者价格与有时称为合同价格的价格相同，即农民在一定年限内签订合同向经销商交付一定数量玉米的价格。