- Historic Sites
The Conundrum Of Corn
It’s our most important, profitable, and adaptable crop—the true American staple. But where did it come from?
August/September 1980 | Volume 31, Issue 5
By the time of the European discoverers, all the modern types of corn were already in existence (there are five—flint, dent, flour, sweet, and popcorn). What the Indians had achieved by instinct and experience was good enough for the white settlers. They did nothing more in the way of selecting and improving, mostly because they did not know where to begin. Corn is a unique plant. It carries the male flowers on top in a tassel and the female flowers lower down on the stalk. Since there is nothing else like it in nature, it is known botanically as a “monstrosity.” Nevertheless, the monstrous arrangement is ingenious and efficient. Pollen ripens in the flowers of the tassel. As it does, silk strands start to grow from an ovary attached within a husk to an incipient cob. After the pollen starts to fall—but never before—each silk emerges and reaches to catch a grain of pollen on its sticky end. If a silk goes unpollenized, no kernel will form. European scientists knew corn for two centuries before they realized that it—or any other plant—reproduced by a sexual process. Toward the end of the seventeenth century, the German Camerarius, experimenting with beans and corn, proved that fertilization caused reproduction. In America, shortly after, his findings were documented by three Americans, all better known for things other than botany. Cotton Mather, the theologian, studied what happened in a field in which a single row of red- and blue-kerneled corn was planted among rows of yellow corn. “To the windward side,” he observed, “this red and blue row so infected three or four whole rows as to communicate the same color unto them.” But on the leeward side, the corn remained almost all yellow. It was the first report of corn hybridization. Then a contemporary of Mather’s, Paul Dudley, chief justice of Massachusetts, reported that “if in the same field you plant the blue corn in one row of hills and the white or yellow in the next row, some of the ears in the blue corn rows shall be white or yellow and some in the white or yellow rows shall be of a blue color.” Indians believed the mixture came about because the roots touched, but, Dudley stated, the plants were too far apart for this. The wind, he said, was responsible for what he called “this wonderful copulation.”
Then James Logan, who managed Pennsylvania for William Penn and was one of the leading intellectuals in the colonies, made a precise experiment. In 1727, in the four corners of his Philadelphia backyard, he planted hills of corn. In one corner, he cut the tassels off the plants. In another, he covered the silks. In the others, he cut off varying numbers of silk. When he picked the ears, there were no kernels where the tassels had been removed or the silks covered. In the others, the number of kernels matched the numbers of silks that had been left. The function of pollen and silk was thus established.
All this was done in pursuit of knowledge, not of more or better corn. The first man to put such knowledge to practical use was John Lorain, a Pennsylvanian with a curious mind—he once sought out George Washington to ask the President about his methods of planting potatoes between rows of corn. Lorain worked a farm in southern Pennsylvania, a border region where farmers planted two kinds of corn. One was flint corn, favored in the North, which had firm kernels, smaller ears, and ripened early. The other was a dent corn, named for the dimple in its kernel, called Gourdseed, which had heavier ears, softer kernels, and ripened later. In this overlapping area, Lorain noticed that the crossbreeding of flint and Gourdseed produced new strains that were heavier and more productive than flint, firmer and earlier than Gourdseed. “A judicious mixture” of the two, he concluded, could yield “at least a third more per acre” than any other kind, and he urged that corn should be bred and selected to keep “the valuable properties” while “the inferior may be nearly grown out.”
This was sound advice, but chance was just as important as method in carrying it out. In 1845 Robert Reid, an Ohio farmer, moved to Illinois, taking with him a Gourdseed strain. In the cool Illinois spring most of the seed rotted, and to fill out the hills he planted a flint corn called Little Yellow. The two kinds cross-pollinated, and the result was a wonderful new strain, hardier and better-yielding than any corn Reid knew. Breeding carefully—his son James used to keep the best ears between two mattresses on his bed to protect them from mice—he developed a large, good-looking, reliable variety—Reid’s Yellow Dent. It was the most important single strain developed in modern America.
Meanwhile, corn growing moved westward. In 1840 Ohio, Kentucky, Tennessee, and Virginia were the leading growers. Twenty years later Ohio, Illinois, and Missouri had become the leaders. It cost forty cents a bushel to grow corn in New England, as little as twelve cents in Illinois.
The Indians could never grow corn in their richest land, the prairie, because they could not break the sod. The white man’s plow could. Where corn went, pigs followed. In 1804 an Ohio farmer named George Rennick decided to get his corn to market by feeding it to his pigs and walking them over the mountains to Baltimore. He lost one hundred pounds off each hog, but even then the profit was very big. By 1850 the pigs were going to Cincinnati, which some called “Porkopolis,” and the hogs were known as “land whales” because their fat was replacing the diminishing supply of whale oil.