History of Hybrid Corn

In its special fall issue of 1992, Time magazine declared the 
hybridization of corn to be one of mankind’s greatest achievements of the last one thousand years. In 1942, Iowa farmers became the first farmers in the nation to plant their entire acreage with hybrid corn—a huge milestone considering that in 1933 less than 1 percent of the total corn acreage had been planted with hybrid corn. Since its inception, the development of hybrid corn has proven to be an unprecedented breakthrough in food production in America. With its astronomical yields, hybrid corn has provided an abundance of corn for both food and non-food uses. It deserves to be ranked with such epic discoveries as broadcasting, air travel, and the computer. Corn 
hybridization touched off a revolution in agriculture—a revolution 
embracing farm machinery, farm chemicals, and drastically different farming practices.

Before the dawn of hybrid corn, farmers in the Corn Belt planted
open-pollinated corn, rarely producing average yields of thirty
bushels or more.

The 1940s, the first decade in which double-cross hybrid corn
assumed national importance, witnessed the nation’s first major sustained increase in corn production. By the 1950s, hybrids widely used in the 1940s were being replaced by new and superior double-cross hybrids that could produce stronger 
stalks that stood well throughout the growing and harvest seasons and held heavier ears.

The development of hybrid corn led to major changes in how farming was done. Corn pickers pulled 

by horses had been tried in earlier years, but had not been successful in fields planted with open pollinated corn, where broken stalks and ears on the ground were too prevalent. The corn had to be picked by hand in order to maximize yields. Double-cross hybrids changed all that. Farm horses gradually disappeared. Tractors became more numerous, and the mechanical harvesting of hybrid corn soon replaced the labor-intensive practice of hand picking. By their nature, double-cross hybrids could also tolerate higher levels of fertility, and soon farmers began using more fertilizer, especially anhydrous ammonia. By the 1960s, the new single-cross hybrids had replaced the earlier double-cross varieties in the top corn-producing states, raising yield potentials even further.