Customer Notification Postcard, "The Pioneer Seed Corn You Ordered Has Arrived," circa 1958

In the 1930s and 1940s, American farmers stopped saving their seed corn, and began to plant seeds purchased annually from companies that specialized in scientifically crossed varieties of hybrid seed. Production greatly increased, but it also added additional cost. Today, farmers proclaim their allegiance to brands by wearing their preferred company's hat or placing signs in their field.