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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
In 1748 an inquisitive Swede named Peter Kalm, a protégé of the great botanist Linnaeus, came to America to find plants that could be useful in his country. He went around asking questions of everybody about everything. He asked Benjamin Franklin about hardy trees and was told that English walnuts did not survive Philadelphia’s winters. He asked John Bartram, the most knowing botanist in the colonies, about timber and was told that American oaks were not as tough as European. He asked Cadwallader Golden, later to become the lieutenant governor of New York, about medicinal plants, and was informed that the root of skunk cabbage helped cure scurvy.
But the answer to one question eluded Kalm. Everywhere he went he asked about maize, or Indian corn. He found out the Indians baked it into bread (adding huckleberries in season), brewed it into beer (blue-colored corn was best for this), and used it as a poultice (for curing boils). But he was balked when he asked the simple question Where did corn come from? A blackbird brought it from the west, said some Indians. A beauteous maiden shook it out of her hair, said others. These answers, of course, did not satisfy Kalm’s Enlightenment mind.
Scientists today can appreciate his frustration. Ever since he asked it, they have been repeating his simple question—where did corn come from?—and after two centuries or so have come up with only half the answer. After long deliberation, they have pretty much agreed that corn came from this continent—not from Asia as some once thought— and grew originally in middle America. That settles the geographical question but not the genealogical one: What is corn’s ancestry? The search for the answer has sent botanists into fruitless hunts for hypothetical wild grasses and put geneticists through tedious evolutionary exercises in breeding corn backwards. It pits three main schools of thought against each other—Mangelsdorf versus Beadle versus Weatherwax. And it provokes long seminars in which, sooner or later, someone refers to the “mystery of maize.”
It seems strange that so familiar and open a plant as corn, whose very name is a metaphor for the obvious, should have any mystery about it. Everybody knows corn. It is a staple crop not just in Nebraska but in Bulgaria, Nigeria, and Thailand. A highly adaptable plant, it grows from Canada to Chile, in humid sea-level marshes and rarified Andean plateaus. A most amenable plant, it breeds so readily and crosses its genes so promiscuously that any kind of corn for almost any purpose can be created. Universally useful, it fattens hogs and cows while nourishing man with tortillas and polenta, enlivening him with beer and bourbon, and holding things together in wallpaper paste and jelly beans.
Nonetheless, corn still presents a mystery, and smack in the middle of it is a Mexican weed called teosinte. A tall, tasseled plant that is found in and around cornfields, it looks so much like corn in its early stages that farmers neglect to pull it out. It pollinates corn freely and just as freely is pollinated by it. Modern corn, in fact, has some teosinte in its genes. Teosinte is so much like corn in so many ways that everyone agrees it is a relative of corn. But which relative? The Beadle school says teosinte is the ancestor of corn. The Mangelsdorf school argues, instead, that corn is the ancestor of teosinte. The Weatherwax adherents say that corn and teosinte descend from some common ancestor, making them cousins.
A hundred and fifty years ago it was believed that a primitive kind of corn named pod corn was the wild progenitor of modern corn. Then, later in the nineteenth century, when the relationship of corn and teosinte was recognized, the teosinte-as-ancestor theory took hold. In 1939 Paul Mangelsdorf of Harvard and R. G. Reeves of Texas went back to the pod corn theory.
After amassing persuasive genetic and botanical evidence for their belief, they found concrete support in archaeology. It came first in 1948 from the Bat Cave in western New Mexico, where prehistoric Indians lived from about 3000 B.C. to A.D. 1000. The leftovers of their tenancy lay untouched in the cave floor—layer after layer of garbage, offal, excrement, broken pottery. Digging methodically, excavators found 776 corncobs. Not a single one had a kernel left on it. But over the centuries 125 kernels had been carelessly dropped and overlooked by beetles and rodents (though back at Harvard, where they were studied, modern mice got into the cache of ancient kernels and ate several). At the bottom were tiny cobs, five thousand years old. In the oldest remnants, there was no indication of teosinte. An even older find was made by an expedition working caves at Tehuacán near Oaxaca in Mexico, where diggers uncovered a seven-thousand-year-old cob. From all the evidence, Mangelsdorf concluded that this was wild corn. And when drillers in Mexico City found grains of cornlike pollen at soil levels eighty thousand years old, long before man came to America, Mangelsdorf was sure of his thesis. The ancestor of corn, he said with finality, was corn.
This finality, however, did not impress other scientists. The Beadle school dismissed the Tehuacán wild corn as an early cultivated variety, since man was known to be farming by then. And they declared the dating of the old pollen to be highly suspect. They offered their own complex genetic data to prove that only a few minor mutations in teosinte, which was growing at least seven thousand years ago, would give it cornlike qualities. When that happened, they theorize, the Indians who collected teosinte seed as marginal food noticed the improved varieties and, one way or another, grew it for themselves. Gradually teosinte evolved into corn. Isn’t it odd, they ask the Mangelsdorf school, that ancestral strains of wheat, barley, and other grains still grow wild today but no one has ever found any wild corn? Isn’t it just as odd, retort their opponents, that no one has ever found any traces of teosinte at one of the stages it supposedly passed through while evolving into corn?
The arguments, far more subtle and hedged than this summary suggests, are made knottier by another relative of corn and teosinte: Tripsacum, sometimes called gama grass, which grows in many parts of the Americas. The late botanist Paul Weatherwax of Indiana University, studying the resemblances between the plants, deduced that all three descend from the same wild grass. Though his theory has less support—at least less vociferous support—than the others, it has not been altogether discarded.
Everything could be settled, of course, if someone could find a missing link between teosinte and corn, or some corn everyone agreed was wild. (Modern corn relies on man to survive. It cannot disperse its seed, and if an ear fell to the ground, the kernels would sprout into plants so numerous and close together that they would choke each other out.) In the 1960’s a squad of plant hunters mounted a botanical safari in Mexico to gather some seventy-five thousand samples of teosinte and look for evolutionary clues. But as Mangelsdorf gleefully saw it, it was a search “proving nothing scientifically but providing its participants with a memorable adventure.” Mangelsdorf himself, who admits that his lifetime spent in the study of one plant “can be regarded as a form of monomania,” undertook to create wild corn in his test plots. Trying to reverse evolution, he bred corn backwards, emphasizing its most primitive characteristics. He failed to reconstruct a wild species but he did wind up, as he put it, with “probably the world’s most unproductive corn.”
George Beadle, who won a Nobel Prize for his work in medicine and physiology, actually submitted his own digestive tract to support his pro-teosinte theory. Citing what he called “a friendly disagreement with Professor Mangelsdorf on the edibility” of teosinte, he undertook the Scrimshaw test. Following a regime devised for him by Dr. Nevin Scrimshaw, a nutritionist at the Massachusetts Institute of Technology, he set out to eat teosinte as prehistoric man would have: crushed seeds, hulls and all. After four days on this diet, the intrepid Nobel laureate announced that he suffered “no unpleasant consequences.”
Geologists and paleontologists have been on constant lookout for evidence of fossil corn. There was a furor some years ago when the Smithsonian Institution acquired a petrified ear of corn that had been unearthed in a curio shop in Cuzco. After some soul searching, the institution decided to analyze it rather than put it in a showcase. So the cob was dissected—and it turned out to be an ancient toy, a child’s rattle beautifully made of clay to imitate an ear of corn.
If the disciplines of modern science have been of no use in answering Kalm’s question, neither have the myths he discarded. While eastern Indians said a crow brought corn from the west, the Navahos said a turkey hen flew from the east and dropped a blue ear of corn. The Mayans believed their god-hero Gucumatz, knowing man needed corn, went through grievous perils to bring it to him. The Aztecs told that corn came from the western gardens of Tomoanchan, where goddesses lived, and was brought underground to the red land of dawn where the quetzal bird sings. The Abnaki Indians recited the tale of a lonesome brave who was visited by a lovely light-haired woman. She promised to be with him always if he would do as she said: “Rub two sticks together, burn a plot of grass and, when the sun goes down, take me by the hair and drag me over the ground. Grass will grow where I am dragged and hair will come up between the leaves.” Reluctantly the Indian did what she said, and so corn came to mankind—a lovely story but better perceived, perhaps, by Freudians than by farmers.
In the mundane world, corn came late to the agricultural Iage. By 8000 B.C., men in southwest Asia had stopped relying on collecting wild grain for food and were cultivating it. By 6000 B.C., the practice had reached Western Europe and, at about the same time, it had already begun in America, where Indians raised chili peppers, avocado, squash, beans, and corn. Domestication came everywhere through the same accident. Edible seeds of wild plants, dropped around encampments, landed on heaps of garbage and offal. In this richer soil, plants grew bigger and were handier to harvest. This led to the purposeful sowing of seed, to cultivation, and finally to the saving and selection of seed from the best plants.
By the time the white man came, corn was the main cultivated crop in all the Americas. In his journal entry for November 5, 1492, Columbus described “a prolific sort of grain from which a very fine flour is made … a bread of exquisite taste.” It was “a grain like millet which they called maize,” a landing party reported, “very well tasted when boiled, roasted or made into porridge.”
Thus the Old World first met the plant on which the New World built its wonderful civilizations—the temples of the Mayas, the gold and silver work of the Incas, the enchanting Aztec city of the lakes. To the Indians it was worshiped as the stuff made by gods, the stuff of which man himself was made, his source and sustenance. It was so cheap to produce—a single plant gave a man enough food for a day—that it could support generally stable populations, leaving people with free time to create monumental wealth for their priests and chieftains.
In much of middle America, farming procedures were simple. In a spot near a village, farmers would cut down trees and, leaving them to termites and decay, plant corn between the stumps in scuffed-up hills. The ground was rich in decayed vegetation and, having been shaded by trees, was free of weeds. The corn grew robustly. In three or four years, with the soil depleted and other plants moving in, the plot would be abandoned for another.
In Mexico, corn grew so tall along the trails that Cortez’s cavalry had trouble pushing through to get to Montezuma’s capital. They found the city streets lined with booths that sold flat corn cakes, and everywhere they heard the noise of the cakes being slapped and thrown on stone hearths. The plain people ate them filled with beans or pimientos, the conquistadors noted, while the rich filled them with meat, feasting also on winged ants and the caviar-like eggs of water flies. The conquerors also learned a dish called tlacatlaolli made of the flesh of a man, sacrificed in a harvest ritual, cooked in a stew with the first-picked corn.
To the northwest, Coronado, searching for those golden cities, met corn all along the way growing in arid spots where the Indians build little basins to catch the sparse rain. Far to the north, Cartier and Champlain found corn that ripened well despite the short summer.
Columbus brought corn back from his first or second voyage, and by the mid-1500’s it was growing not just in Spain but in Bulgaria and Turkey. Slavers carried corn to Africa to feed their cargo and it caught on there, proving more productive than native grain. Magellan’s men dropped Mexican seed off in the Philippines and Asia.
Spaniards first called it panizo, a general term for grain, but soon adopted the name maize. Other Europeans called it Indian corn, Indian barley, Guinea wheat, or when they wanted to disparage it, Turkish corn or Welsh corn—anything from Turkey or Wales was considered coarse and uncivilized. The tireless classifier Linnaeus, who named or renamed almost everything in nature, called it Zea mays, zea meaning “cereal” and having some remote connotation of “life.” The term corn, which in the Bible meant any grain, eventually took over as the popular name.
The English in America had to be taught the virtues of corn. Thomas Hariot, who came to Virginia in 1585, described it as “a graine of marvellous great increase.” A pound of seed, he said, produced three or four hundred pounds of food. The settlers at Jamestown did not appreciate this local marvel. They insisted on planting wheat, and many starved for their stubbornness. Captain John Smith had to spend a good deal of time badgering the Indians for corn. It was on a corn-buying trip that he claimed to have been saved by the first all-American heroine, Pocahontas. Her father, Powhatan, bargained hard after pardoning Smith. “A subtle savage,” Smith called him and, for a boatload of corn, had to give the chieftain “a grindstone, some guns, a cock and a hen, together with much copper and beads and some men to build him an English style house.”
Although Smith ordered the settlers to harvest and store their first corn crops carefully, he discovered that some of the inhabitants, none of the best husbands,” simply picked their ears and threw them unhusked on the floor. But “the good husbands” husked it and “with much labor” hung it up—where, Smith reported, the weevils ate most of the corn while touching “not a grain” of the others. The moral of this perverse grasshopper and ant story, said Smith, was that the best way to preserve corn was to let it “lie in the husk, and spare an infinite labor that formerly had been used.”
Up in New England, a few days after the Pilgrims had landed, Miles Standish led a party out in search of food. Near some stubble, they found, as William Bradford chronicled it, “heaps of sand newly paddled with their hands which they, digging up found in them corns of diverse colors which seemed to them a very goodly sight having never have seen such before. They returned to the ship and … carried with them the fruits of the land and showed them to their brethren of which they were marvellously glad.”
That winter Squanto came to help bury the Pilgrims’ dead and then teach them how to plant corn. A Patuxent Indian who had been picked up by a British ship and had learned to speak English in London, he had been returned to Cape Cod. “A special instrument of God,” Bradford called him, “who directed them how to set their corn” and told them that “except they got fish and set with it, it would come to nothing. ” The settlers buried a fish in each hill of corn and, when their wheat and peas failed, the twenty acres of corn kept them alive.
Corn was far more suitable for them than wheat. It grew more reliably, yielded more grain. Its harvest was conveniently spread out and it did not have to be carted to a mill to be ground into flour. The Pilgrims planted it the Indian way, four or five seeds in well-spaced hills, and stored it as the Indians did, in clay-lined baskets buried in the ground. They picked a few early ears to eat as sweet corn but dried the rest, for porridge or bread. As whites went west, they found different recipes. Meriwether Lewis wrote that the Mandan Indians fed him a dish “of pumpkins, beans, corns, chokecherries all boiled together and forming a composition by no means unpalatable.” Other explorers found it hard to stomach the Omahas’ ta-she-ba, corn boiled with buffalo intestines, but one of them, the aristocratic Prince Maximilian of Wied, declared that corn “cooked with bear’s flesh was beyond comparison, delicious.”
In the West corn was grown on a relatively large scale, with the growers selecting the best seed and getting good yields of twenty bushels per acre. This is not surprising, because over the centuries the Indians had developed strains of corn whose productivity still impresses growers today. The hemispheres had been a huge botanical laboratory where patient farmers worked with one of the most supple genetic tools known to man. Because corn crossbreeds so readily and its genetic make-up changes so frequently through mutation, the Indians were presented, generation after generation, with new varieties that were tested, willy-nilly, under all conditions. Keeping the seeds they found best for their own particular use or taste, they slowly improved the breed. Cortez counted at least twenty different varieties of corn on his march inland. Mexicans, who softened their corn in lye water and ground it for tortillas, aimed for firm corn that would not get mushy. In Peru, where kernels were eaten whole, boiled or parched, the goal was larger, softer kernels. Families regarded collecting corn seed as a sacred duty. Their careful selection kept strains astonishingly uncontaminated—no test plot today could keep them purer.
It was simpler for farmers to do this with corn than with other crops. Wheat or barley, for example, were sown broadcast and harvested wholesale with a sickle. Corn was planted seed by seed, tended and picked plant by plant. The farmer could see how every plant grew and give the best of them special attention. Present-day scientists also acknowledge the importance of a factor that rarely gets into modern appraisals: the respect and even affection an Indian farmer showed for his corn.
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.
The great scientific era of corn breeding did not begin until late in the century. In 1871 Charles Darwin, working with corn, found that inbreeding a strain of corn would weaken it, but crossbreeding an inbred with another variety would revive it. William James Beal, at Michigan Agricultural College, who corresponded with Darwin, began the first controlled crossbreeding of corn and produced strong hybrid strains.
Thirty years later, George Harrison Shull, working in a Long Island laboratory, developed Darwin’s thesis. Setting out to study the workings of heredity, he chose to work with corn because it is such a handy evolutionary tool. Its chromosomes are large, easily observed and manipulated; its tassel-ear separation makes pollenization-control simple; and it carries a multitude of characteristics in its genes. In fact, next to the salivary glands of the fruit fly, corn is the favorite subject of genetic experiments. To isolate the characteristics he wanted to study, Shull inbred varieties and found, as Darwin had, that the more he refined them, the more he weakened them. However, when he crossed the puny inbred of one line to the puny inbred of another line, a procedure known as a single cross, he attained what he described as “an extraordinarily powerful hybrid … more vigorous than the best of the inbred races.” He called the phenomenon heterosis, or hybrid vigor.
Shull’s work was more or less duplicated by Edward Murray East in Connecticut, but neither pushed their results to practical use. (East went off to teach at Harvard while Shull returned to work on his first botanical love, the evening primrose.) Their hybrid did not, it turned out, produce seed in profitable amounts, but a student of East’s, Donald Jones, overcame this. He took a single-cross hybrid produced by crossing two inbreds, and crossed it with another single cross. This was a double cross, and the result was splendid—large, vigorous plants and ears that produced seed in profitable quantities. Like Robert Reid, Jones had luck on his side. There were only two single-cross strains available in the laboratory, so he had to use them. Later experimenters found that double crosses fail ninety-nine times out of one hundred. Jones happened to have the one in a hundred that would work.
It remained for a politician who has been looked on largely as an idealist and a dreamer to make practical use—and a great deal of money—out of hybrid vigor. Henry Agard Wallace’s grandfather, always called Uncle Henry, had been a Presbyterian minister who settled in Iowa after the Civil War and grew rich from intelligent farming and shrewd land buying. Eventually he became editor of Wallaces’ Farmer and preached, as his masthead proclaimed, “Good Farming, Clear Thinking, Right Living.” In 1902 he met a man whose philosophy matched his own: Perry Greeley Holden, always known as P.G. There must have been some atavistic Indian reverence for corn in P.G. Better corn would not only make men better farmers, he believed; it would also make them better men. A student of Beal’s, he had given up a professor’s post to help develop and distribute improved strains of Reid’s Yellow Dent. When he came through Iowa promoting his seed, Uncle Henry decided Iowa needed a man like him and, putting up part of the salary himself, he got the state college at Ames to take him on the faculty.
P.G. had a vision of an ideal corn: uniform ears, nine and one-half to ten and one-half inches long, with even rows and deep kernels shaped like a keystone. To help his evangelist, Uncle Henry coaxed the railroads to set up corn trains to carry P.G.’s corn and message to all farmers. Corn-growing competitions, called corn shows, became an annual event in the Midwest. Farmers would enter their best, most uniform ears. Judges, all trained to follow P. G.’s precepts, would lay them out, compare them, feel the kernels, run fingers over the ear, heft them. The best ear got ten points, the poorest only one. Winners gained cash prizes and great prestige. Getting ready for the contest, a farmer would pore over bushels of corn to match his best ears, carry them to the shows as if they were ingots of gold, and often when he got there, he would swap with other farmers to get more exactly matching ears. Sometimes he would paste kernels into the cob for evenness, soak an ear in water to make it fuller, or poke a metal rod into the cob to make it heavier.
All this made farmers more discriminating about the corn they grew. But one day in 1904, Uncle Henry’s sixteen-year-old grandson, Henry Agard Wallace, heard P.G. hold forth on show corn. Young Henry knew a good deal about plants—George Washington Carver, the famous black scientist who went to college at Ames and was a family friend, used to take him on botanical field trips. Henry asked P.G.: Would a ten-point ear of corn produce more corn than any other? Of course, P.G. replied, though he had never really looked into yield. When the boy persisted, P.G. and Henry’s father (later Warren Harding’s Secretary of Agriculture) decided he should find out for himself. They collected twenty-five ears of the best show corn and twenty-five of the poorest. On a three-acre piece of land, Henry spent a diligent summer planting and tending his fifty specimens. The harvest justified his skepticism: the highest yield came from an ear no corn-show judge would look at twice. And as a whole, the highest-ranked show ears produced less than those that ranked lowest.
When he went on to agricultural school and began to write for Wallaces’ Farmer, Henry took out after corn shows. Men might appreciate a good-looking ear of corn, he said, but what are looks to a hog? Following the work done by Shull, East and Jones, he began to work on double hybrids on his own farm. Those few adventurous farmers who bought the seed of one of his strains found it the most productive corn they ever grew, so in 1926 Wallace formed the Hi-bred Corn Company to produce and sell his hybrid seed. He ran the company until he became Secretary of Agriculture. All through his years as secretary and vice-president he would come back to see how things were going and, from the corners of his pockets, bring out seeds of odd strains he had picked in his travels.
It was not easy to sell the early hybrids, uneven and unattractive, to farmers accustomed to sleek show corn. In 1935 barely one per cent of the country’s corn acreage was hybrid. In 1936 a dreadful heat wave—over one-hundred-degree days for two weeks—hung over the corn belt. An Illinois farmer named Walter Meers, dreaming of growing one hundred bushels per acre, had taken a chance on a field of hybrids. He watched in despair as all his corn wilted and dried in the heat. When rain came, it was too late to help his corn—except that field of hybrids which straightened up, greened out, and for all the traumatic heat, produced a miraculous one hundred and twenty bushels per acre.
Other farmers had similar experiences, and yield and stamina finally settled all doubts about hybrids. By 1940, as much as 40 per cent of the country’s corn was hybrid. Today it is 98 per cent, the average yield is well past that dreamed-of goal of one hundred bushels per acre, and Wallace’s company, now called Pioneer Hybrid International, is the largest corn-seed producer in the world.
Corn is easily America’s most important crop. A fourth of the total farmland is planted to it, and it brings more dollars than all other grains put together. Iowa, Illinois, and Nebraska are the leading producers—Kansas, the cliché synonym for corn, goes in much more for winter wheat. In dollars, corn means more than maple syrup to Vermont and more than peaches to Georgia. About a fourth of the total crop is exported. Domestically, some 85 per cent is used for animal feed, with hogs getting about half of that.
Most of the remainder goes to industry and is used largely for its starch. An improvement in its sweetening powers has made corn competitive with sugar, and the discovery that cornstarch could be made into a super slurper that soaks up a thousand times its weight in water has helped cornstarch sales and done wonders for the paper-diaper business. Only a minor percentage of the crop goes into bourbon, which must be 51 per cent corn liquor to deserve the name, or into corn oil, or into popcorn, a special variety in which steam built up inside the heated kernel causes it to explode and turn inside out. Sweet corn, a minor crop, is sweet because it is less efficient than other kinds in turning its carbohydrates into starch. This inefficiency is known botanically as a “metabolic defect,” certainly one of nature’s happiest defects.
Corn breeders today are trying to meet special conditions. Short-summer strains now make it possible to grow corn two hundred miles farther north than the Indians ever could. New varieties have been made resistant to diseases, notably leaf blight, which in 1971 wiped out 800,000,000 bushels of Southern corn. There is intensive work going on to increase the protein content of corn. For all its great food value, corn is relatively low in protein, a serious lack in poorer countries where corn is the main item on the diet. It has been possible to increase protein, but in doing so the plant’s vigor and yield has been diminished, so the research continues. All in all, the successes of modern corn scientists have been impressive. Of course they had all that good stock to start with, provided by the uncounted generations of Indians who had done a piece of creative work unmatched anywhere in agriculture. Even modern scientists haven’t really matched it but, considering that they have had only a couple of centuries to work in while the Indians had several millennia, they have nothing of which to be ashamed.
Several months ago, the corn world was stirred by the discovery in Mexico of a hitherto-unknown perennial variety of corn’s weedy kin, teosinte. It might someday, through interbreeding, contribute useful characteristics to corn. Meanwhile, it is giving new zest to the dispute over corn’s lineage. Dr. Mangelsdorf, happily out of retirement, was back in the testing fields, hoping, by crossing the new plant with corn, to prove once and for all that teosinte is corn’s progeny, not its progenitor. Dr. Beadle, back in the laboratory, was expecting to prove the opposite by tinkering with the teosinte’s genes. Other corn men, who have long envied the fact that the ancestry of wheat, rye, oats, rice, and barley is established, wish them both well. If the new teosinte could lead them to some missing genetic link, whatever it might be, then corn would no longer be the only one of the world’s great grains that does not have an ancestor to call its own.