The Era Before Hybrid Corn

Since the 19th century, the U.S. Department of Agriculture, the agricultural colleges, and the experiment stations had bred crops for yield and resistance to diseases, insects, and drought, but by 1900 this work had not affected the lives of most farmers. They judged a crop by inspection, saving seed for planting the next year from plants that yielded well or manifested no damage from insects or disease. The farmer saved several ears of corn, for example, through the winter. A few weeks before planting he wrapped a single kernel from each ear in a wet cloth, planting in the spring seed from the ears whose kernels germinated and discarding those ears whose kernels did not germinate. This brand of agriculture required no science, only a keen eye and attention to detail.

Much of the efforts of scientists and farmers concentrated on corn, an indigenous grass that humans had grown for millennia. In the early 20th century, the Corn Show swept the Corn Belt of the Midwest. An annual contest analogous to the county fair, the Corn Show trumpeted the virtues of rural life and clean living and was as much about civic boosterism as it was about judging corn. The Corn Show substituted beauty for economics, eschewing yield as the criterion for evaluating corn. Rather, judges prized large ears with straight rows, full and uniform kernels, and no bird or insect damage. The winner claimed bragging rights in the county.

Agricultural scientists made the rounds at the Corn Show, renewing acquaintances and sharing their latest research in an informal setting. Some scientists championed the Corn Show for making farmers careful observers of their crop, but others derided the emphasis on aesthetics. In their view yield was the only measure of corn that mattered, and they set to work with the aim of breeding high-yielding varieties regardless of how these varieties looked.

In 1905 agronomist Cyril George Hopkins at the Illinois Agricultural Experiment Station devised the ear-to-row method of breeding corn. Hopkins collected ears from several corn plants, planting the seed from each in its own row. Because all plants in a row were siblings Hopkins could easily maintain the pedigree of each plant. Hopkins hoped that by keeping seed from only the highest-yielding row and repeating the ear-to-row method he would select for corn with progressively higher yield. Although the ear-to-row method allowed Hopkins to derive corn with high protein and oil, he made no headway in yield.