After being grilled by Stakman in the lab, Borlaug attended one of his lectures. The subject was Stakman’s special passion, the black stem-rust fungus, a parasite that attacks wheat. Stem rust is little known today outside agriculture, but it was long one of humankind’s worst afflictions, responsible for millennia of famine. Borlaug knew it well; a stem-rust outbreak had driven his grandparents out of the wheat business in 1878. Epidemics in 1904 and 1916 had led to misery throughout the Middle West and northern Europe. Stakman had been fighting the fungus for more than two decades. Years later, Borlaug would join his anti-rust crusade—and find himself in the blasted field outside Mexico City.

  Stem rust was long so pervasive and unstoppable that the Romans viewed it as a malign deity, and sacrificed rust-colored dogs to appease it. Only centuries later did scientists learn that stem rust is actually a fungus, not a supernatural force. The term “fungus” makes rust sound simple. In fact, stem rust is a wildly complex creature, a triumph of evolutionary guile. “All five types of spore reproduction!” Lynn Margulis once told me, her eyes agleam. “What’s not to like?” In her opinion, the fungus was vastly more interesting than the wheat it infects.

  Rust-infected wheat plants are stippled like smallpox victims with countless small, rust-colored pustules, each packed with thousands of spores. The spores, a millionth of an inch long, cannot be seen by the naked eye. The slightest wind carries them in a thin mist high into the atmosphere. They saturate the air in unbelievable profusion and can spread for miles. In banner years, write the environmental historians Garnet Carefoot and Edgar Sprott, “more rust spores are produced in the world than there are blades of grass or grains of sand in all the world’s beaches or stars in all the galaxies of the universe.” Carefoot and Sprott were exaggerating, but less than one might expect; a single acre of “moderately rusted wheat,” Stakman once estimated, can produce 50 trillion spores.

  Stem rust has a complicated path through life that involves no fewer than four developmental stages. The most consequential for humankind is the stage in which it attacks wheat. But the most important for the fungus is the stage in which it feeds on an entirely different plant: European barberry. A spiny, shoulder-high shrub, barberry has small red berries that make a tart jam. European migrants carried the plant across the Atlantic, and spread it through most of the United States and Canada. On wheat, stem rust produces spores asexually; the spores grow into fungi that are genetically identical to their parent. On barberry, stem rust produces two different types of spores—“male” and “female,” so to speak—that combine sexually to produce spores that are not genetically identical to either parent. Some of Stakman’s earliest research showed how this sexual-style reproduction, which rapidly creates new combinations of gene variants, allows stem rust to exist in scores of different strains, each with its own abilities.

  In colder parts of North America and Europe, the fungus cannot survive winter in the wheat fields. It has two means of returning. The first occurs in places like Mexico or North Africa, where the climate is never cold enough to kill the fungus. Wind perpetually blows spores from these warm reservoirs of infection into colder regions in the north. In late spring, when temperatures rise, the spores can survive this journey and afflict young wheat plants. Puccinia graminis is the scientific name for black stem rust. Its south-to-north pathways are known as “Puccinia highways.” The second mode of attack occurs within colder areas themselves. In early winter, before the weather turns deeply cold, the fungus creates a type of spore that afflicts barberry. These can survive throughout the winter. In early spring the barberry-type spores germinate, spread through barberry leaves and stems, and erupt through the surface to produce yet another type of spore, this one capable of infecting wheat. Every year, both types of spore—those blown up the Puccinia highway, and those spread from barberry—assault northern farms in a double attack.

  In 1916 stem rust ravaged North America, wiping out almost a third of the harvest. Bread prices shot up in response. A year later, the United States entered the First World War. Fearing food shortages, Washington quickly moved to bolster farm production. Plow more land! Harvest more wheat! it exhorted U.S. farmers. Posters appeared: food will win the war. Stakman became head of the War Emergency Board for Plant Pathology. He used his new pulpit to broadcast a message: Puccinia graminis was the greatest threat to U.S. grain, and the best way to fight it would be to wipe out barberry.

  As U.S. troops went overseas Stakman persuaded Washington to let him run a nationwide campaign of barberry eradication—a pioneering act of large-scale environmental management. The goal was to exterminate the plant from Colorado to Virginia, from Missouri to North Dakota. Hundreds of thousands of handouts, posters, and leaflets described barberry as an “outlaw,” a “menace,” a “dangerous enemy alien.” Brochures exhorted farmers to “execute this criminal bush wherever it is.” Barberry, government press releases claimed, is “pro-German.” Boy Scouts, church groups, Future Farmers of America, federal agents, elementary school classes—all were instructed to search for, dig out, and poison barberry bushes. “Rustbuster” clubs gave medals to children who informed on their bush-owning neighbors. Stem-rust vigilantes tore out barberry with tractors, then poured salt or kerosene into the hole to kill remaining roots. The Great Barberry Zap destroyed more than 18 million bushes in seventeen states in twelve years.

  Removing barberry eliminated the fungus’s sexual reproduction, which slowed the pace at which it could evolve new strains. In previous decades plant breeders had developed rust-resistant varieties of wheat, only to discover that P. graminis had adapted to them within a year or two and was as potent as ever. Expunging barberry threw sand in the fungus’s evolutionary gears. As the barberry campaign crested, Stakman led a team of researchers that developed a new type of rust-resistant wheat. Thatcher, as it was called, made its debut in 1934. Without barberry, P. graminis wasn’t able to overcome it for almost thirty years.

  To Stakman, the anti-barberry campaign showed the power of science to improve human lives. It was a lesson for the future—one that paid off in 1943, when he was asked to develop scientific agriculture in Mexico. The request originated with U.S. vice president Henry Wallace. The Iowa-raised son of a secretary of agriculture, Wallace began breeding experiments as a child, discovering for himself the phenomenon of “hybrid vigor”—that some hybrid organisms can outperform their parents by mixing their genetic inheritances. A polymath and eccentric, Wallace also edited the family newspaper, studied Christian mysticism, made contributions to statistics and economics, and tested fad diets on himself. In college he spent weeks eating only a puree of soybeans, rutabaga, maize, and butter, making himself so sick that he had to leave school to recuperate; at other times he consumed nothing but oranges, or milk, or an experimental cattle feed.

  Stakman examining wheat seedlings in his lab in about 1918 Credit 27

  Government scientists had bred the first successful hybrid maize in 1918. Wallace studied their results, developed them further, and in 1926 founded the company that would become Pioneer Hi-Bred, a major vendor of hybrid maize. Despite Wallace’s idiosyncrasies, President Franklin Delano Roosevelt appointed him in 1933 to be secretary of agriculture, the post once held by his father. Seven years later Roosevelt selected Wallace to be his vice president. After Roosevelt’s re-election in November 1940 Wallace went to Mexico, driving his own car to set a humble tone. The visit was dangerous; the country was locked in conflict between left and right. Fascists rioted in front of the U.S. embassy and attacked the inauguration motorcade; left-wing death threats accompanied Wallace’s every move. Still, he hoped that the visit could soothe the strained relations between the United States and Mexico.

  After the ceremony, Wallace and incoming Mexican agriculture secretary Marte Gómez spent three weeks inspecting rural villages, Wallace insisting on speaking to farmers in his fascinatingly imperfect Spanish. He was appalled to see them planting maize with pointed sticks, weeding by hand, a
nd carrying the harvest to market on their backs. To Wallace, who deeply believed in the Christian message of compassion, it was obvious that something should be done. Conversations with Gómez made clear that direct assistance from Washington to Mexico would be seen as Yankee meddling and was therefore politically unpalatable. Indirect assistance was another matter. A month after his return to Washington, the vice president summoned the head of the Rockefeller Foundation to a meeting.

  Created in 1913 by Standard Oil owner John D. Rockefeller Sr. and his son, John D. Rockefeller Jr., the foundation had an initial endowment of $100 million, an unheard-of sum at a time when the annual federal budget was less than a billion dollars. An early Rockefeller initiative had been to establish the General Education Board (GEB), which disseminated better farming techniques in the U.S. South—methods to prevent the spread of boll weevils and other cotton pests, for example. So successful were GEB programs that in 1914 Congress used them as a model for creating a national network of extension agents: technicians who transmitted the latest agricultural research to local farmers. (The network still exists and is a critical component of the U.S. agricultural system.) In the 1930s the longtime U.S. ambassador to Mexico had begged Rockefeller to replicate the GEB in Mexico. Foundation leaders resisted, fearing Mexico’s long history of antipathy toward U.S. interference. Now Wallace pressed it to reconsider. If maize harvests could be raised, Wallace said, “it would have a greater effect on the national life of Mexico than anything [else] that could be done.” Rockefeller, a private entity, could work quietly, avoiding politics.

  Anxious foundation officials sought advice from experts, among them Carl O. Sauer, a Berkeley geographer who had studied Latin America for decades. Sauer told the foundation that the possibilities were “enormous”—but so were the risks.

  Five to ten thousand years ago, indigenous geniuses in south-central Mexico developed the first maize from a much smaller wild plant, a grass called teosinte. Since that time Indian farmers had bred thousands of varieties of maize, each chosen for its taste, texture, color, and suitability for a particular climate and soil type. Red, blue, yellow, orange, black, pink, purple, creamy-white, and multicolored—the jumble of colors of Mexican maize reflects the nation’s jumble of cultures and environmental zones. The small, varied plots in Mexico were like the anti-matter version of the huge, uniform maize fields in the U.S. Midwest.

  Maize is open-pollinated—it scatters pollen far and wide. (Wheat and rice plants, by contrast, typically pollinate themselves.) Because wind often blows pollen from one small Mexican maize field onto another, varieties are constantly mixing. Over time, uncontrolled open pollination would create a few, relatively homogeneous populations of maize. But the pollination is not uncontrolled, because Mexican farmers carefully select the seed to sow in the next season, and generally do not choose obvious hybrids. Thus there is both a steady flow of genes among maize varieties and a force counteracting that flow. This roughly balanced genetic sea, maintained by farmers’ individual choices, is a resource not only for Mexico but the entire world; it is the genetic endowment of one of Earth’s most important foodstuffs.

  Helping the farmers who maintain this resource, Sauer agreed, would be a good thing—but not if it destroyed their way of life and reduced the diversity of maize. “A good aggressive bunch of American agronomists and plant breeders could ruin the native resources for good and all by pushing their American commercial stock,” he growled. He added, “Unless the Americans understand that, they’d better keep out of this country entirely.”

  Sauer’s warnings thundering in the air, the foundation dispatched three scientists to Mexico: Paul C. Mangelsdorf, a Harvard plant geneticist who specialized in Latin American maize; Richard Bradfield, a Cornell soil expert; and Elvin C. Stakman, who had a long-standing interest in Mexico, the continental reservoir of stem rust. The three men spent six weeks in the summer of 1941 inspecting maize fields from the Rio Grande to the Guatemalan border. What they saw was a human catastrophe: the abridgment of hope on a massive scale. “The great majority of Mexican people are poorly fed, poorly clad, and poorly housed,” they wrote afterward. “The general standard of living of the Mexican people is pitifully low.” And things were getting worse. In 1940 the country harvested a third less maize than it had in 1920, even though it planted almost a million more acres of the crop. Meanwhile, the population had risen by more than 5 million.

  The Rockefeller Foundation was in a position to provide assistance, Bradfield, Mangelsdorf, and Stakman said. Helping was the good—the decent—thing to do. It could station a small group of researchers in the country to offer “a little judicious advice” to Mexico’s newly established corps of agricultural researchers. These could then pass on the results to farmers, mirroring the U.S. extension system.

  The scientists had taken a route through Mexico that was much like the route taken by Bill and Marjorie Vogt two years later. Both groups wrote reports documenting the same terrible poverty and eroded land, but their ideas about the remedy were starkly different. To Vogt, the basic problem was land degradation, and the primary cure was to ease the burden on the land. By contrast, the scientists believed that Mexico’s issues were caused, at bottom, by lack of knowledge and tools. The difference between these two approaches is profound, and at the heart of the split between Wizards and Prophets.

  At the same time, the two reports had a striking similarity: neither attempted to understand how Mexican farmers had got into these straits. When Mexico won its independence in 1821, most of the citizens of the new country were landless peasants who worked on giant estates in conditions little different from slavery. Over time the situation worsened: under the dictator Porfirio Díaz, who controlled Mexico from 1876 to 1910, wealth and land were concentrated among a few hundred aristocratic families, foreign companies, and the Catholic Church. A bloody civil war led in 1917 to a new constitution that promised to redistribute land. Early efforts to fulfill this promise set off such violent resistance by the rich and the Church that the government pulled back. In 1934 a new president, Lázaro Cárdenas, tried again. The Cárdenas administration seized almost 50 million acres from estates and awarded them to ejidos, peasant-run collectives. (About 4 million acres of this land was owned by U.S. companies, which led to diplomatic squabbles between Mexico City and Washington, D.C.) As before, landholders fought back, some plotting coups and assassination attempts. Others ensured that the ejidos were forced to accept bad land—plots that were too dry or steep to cultivate. By 1940 the eleven thousand new ejidos were working almost 2.5 million acres of land that had been left alone ten years before. Unsurprisingly, the consequences were often destructive; erosion and soil depletion soared. Much of the devastation that Vogt saw as the unavoidable consequence of high birth rates was tied to political events that were anything but inevitable; much of the poverty that Stakman, Mangelsdorf, and Bradfield saw as lack of access to knowledge was the result of efforts by wealthy elites to maintain their position.

  A few months after the scientists gave their report to Rockefeller, Japan bombed Pearl Harbor. As the United States mobilized, the advantages of having a calm and prosperous southern neighbor suddenly seemed large. The prospect of helping the war effort nudged the foundation to agree to step into waters it had once avoided. Stakman was asked if he would head the effort. He demurred; he had been swept up by the War Emergency Committee of the American Phytological Society, an ad hoc group that the military had asked to prevent fungi, molds, and mildew from destroying equipment in the Pacific war theater. Instead Stakman recommended one of his students, J. George Harrar.

  Slight in build, fluent in Spanish, both combative and charming, “Dutch” Harrar was an odd choice: he was a city kid who had never worked on a farm, and had never studied maize (like Stakman, he was a wheat-disease specialist). Nonetheless, the choice was successful; Harrar’s affable relentlessness proved to be the right temperament for bilingual negotiation among Mexican bureaucrats, U.S. researchers, and
indigenous farmers. Ultimately, Harrar’s Mexican term was so successful that he was promoted to foundation president in 1961. But in the beginning he spent almost a year extracting the necessary permits from the two governments.

  Expectations for the project were multiple and overlapping. Mexican officials wanted the program to help modernize the nation, but worried about its political impact—they could not be seen as allowing the United States to control a vital economic sector. To contain these anxieties, Harrar agreed that the project would work only in the Bajío, the highlands northwest of Mexico City. The Bajío had been the nation’s agricultural heartland in colonial times but was now wretchedly poor and unproductive. In the United States, Rockefeller Foundation leaders, project scientists, and some politicians—Wallace, especially—hoped that the agriculture project would alleviate hunger. But most U.S. officials viewed it as a mechanism to help stabilize Mexico politically, suppressing the threat of unrest across the border. And scientists, foundation officials, and politicians alike hoped it would rebut Communist claims that poor countries’ poverty and hunger were caused by Western capitalism. “What now are the great enemies of mankind?” Stakman, Bradfield, and Mangelsdorf asked as the program was under way.

  Hunger, the incapacity of the hungry, the resulting general want, the pressures of expanding and demanding population, and the reckless instability of people who have nothing to lose and perhaps something to gain by embracing new political ideologies designed not to create individual freedom but to destroy it….Whether additional millions in Asia and elsewhere will become Communists will depend partly on whether the Communist world or the free world fulfills its promises. Hungry people are lured by promises, but may be won by deeds. Communism makes attractive promises to underfed peoples; democracy must not only promise as much, but must deliver more.