What is an open-pollinated variety?

The name, open-pollinated variety, refers to how the farmers replenished their seed stock. After a new variety was produced by crossing two varieties, a farmer propagated this new variety by saving the seed from the most desirable ears from the most desirable plants each fall. These ears were open-pollinated ears. That is, there was no effort to control the source of the pollen. The pollen that fell on the silks of these ears was dispersed from tassels of nearby plants by wind and insects. The result of this open-pollination was that every plant grown from saved seed was genetically unique. However, all the plants shared certain characteristics that were desirable to the farmer. Grain productivity was certainly one of these characteristics, but not the only one. For example, James Reid, who developed the Reid open-pollinated variety with his father in central Illinois, was an artist. He selected for a corn with a small shank that could be easily hand-harvested without spraining his artist’s wrist. 

All the open-pollinated varieties grown in the United States in the 19th and early 20th centuries were developed by farmers. There were no professional corn breeders. The farmers were the corn breeders.