1493: Uncovering the New World Columbus Created

by Charles C. Mann

  Almost certainly the potatoes made the journey on a guano ship. Between 1532 and 1840 few ships passed directly from Peru to Europe, because Spain, protective of its silver in Potosí, tightly controlled traffic. As Potosí ran out of ore, the silver ships sailed less frequently. In the 1820s Bolivia and Peru gained their independence and Spanish shipping there closed down altogether. European ships were then free to sail to Lima, but few did: the new nations had little to offer and were politically chaotic to boot. In its first two decades, Peru had more than one change of government per year; it also fought five foreign wars. A direct shipping line between Peru and Britain did not open until 1840. It carried guano. As guano frenzy set in, ships by the score sailed from Europe to the Chincha Islands. One traveler there in 1853 saw 120 vessels clustered about the guano docks. Another, later voyager saw 160. Chances are high that one of these ships unknowingly carried blighted potatoes to Belgium—and infected a continent.

  Field trials of West Flanders’s new potatoes began in 1844. That summer a nearby French botanist observed a few potato plants with strange, bruise-dark spots. The following winter was extremely cold, which should have killed any blight spores or eggs in the soil. But the experimenters may have stored a few contaminated potatoes and unknowingly planted them the next spring. In July 1845 the West Flanders town of Kortrijk, six miles from the French border, became the launchpad for Europe’s first widespread epidemic of potato blight. Carried by windblown spores, the oomycete hopscotched to farms around Paris by August. Weeks later, it was in the Netherlands, Germany, Denmark, and England. Governments panicked and ordered more potatoes from abroad.

  Blight was first reported in Ireland on September 13, 1845. By mid-October the British prime minister was privately describing the epidemic as a national disaster. Within another month between a quarter and a third of the crop had been lost. Cormac Ó Gráda, an economist and blight historian at University College, Dublin, has estimated that Irish farmers planted about 2.1 million acres of potatoes that year. In two months P. infestans wiped out the equivalent of between half and three-quarters of a million acres in every corner of the nation. The next year was worse, as was the year after that.

  Recall that almost four out of ten Irish ate no solid food except potatoes, and that the rest were heavily dependent on them. Recall, too, that Ireland was one of the poorest nations in Europe. At a stroke, the blight removed the food supply from half the country—and there was no money to buy grain from outside. The consequences were horrific; Ireland was transformed into a post-apocalyptic landscape. Destitute men lined the roads in their rags, sleeping in crude shelters dug into roadside ditches. People ate dogs, rats, and tree bark. Reports of cannibalism were frequent and perhaps accurate. Entire families died in their homes and were eaten by feral pets. Disease picked at the survivors: dysentery, smallpox, typhus, measles, a host of ailments listed in death records as “fever.” Mobs of beggars—“homeless, half-naked, famishing creatures,” one observer called them—besieged the homes of the wealthy, calling for alms. So many died that in many western towns the bodies were interred in mass graves.

  Click here to view a larger image.

  As resources vanished, life became a struggle of all against all. Starving men stole into fields to steal turnips from the ground. Farmers dug mantraps in their fields to stop them. Landlords evicted tenants in huge numbers, tore down their homes, then went bankrupt themselves. Neighbor fought neighbor for food and shelter. Crime levels exploded, the murder rate almost doubling in two years. Some hungry people stole to put food on the table, others to be fed while incarcerated. In one case two men released from prison were sent back the next day for trying “to break into jail.” The only violent crime to decline was rape, because potential perpetrators lacked the energy.

  Hundreds of thousands of desperate people fled the country in what became known as “coffin ships.” One passenger remembered bodies “huddled together without light, without air, wallowing in filth and breathing a fetid atmosphere, sick in body, dispirited in heart.” The ships marked their passage with a trail of dead slid into the sea. Most migrants went to the United States and Canada. Multitudes of sick and starving filled the quarantine area at Grosse Île, in the St. Lawrence River by Quebec. A mass grave there contains thousands of bodies. They died an ocean away from Ireland but were as much victims of P. infestans as if they had never left.

  In early 1847 the Illustrated London News asked the artist James Mahoney to tour the famine-wracked Irish countryside. His articles and illustrations depicted a landscape of ruins and starving beggars—and did much to bring the crisis to the attention of the English public. (Photo credit 6.5)

  Britain mounted the biggest aid program in its history, but it was catastrophically insufficient—largely, Irish nationalists charge, because London treated the crisis as a chance to expand its efforts to transform Ireland’s “primitive” subsistence farming to export-oriented agriculture. Instead of simply providing food, the British pulled people off the farm, massed them in workhouses, and fed them from soup kitchens; meanwhile, the farms were consolidated into bigger, more export-friendly units. Other critics point to the export of food from Ireland during the famine: 430,000 tons of grain in 1846 and 1847, the two worst years. “The Almighty indeed sent the potato blight,” nationalist leader John Mitchel thundered, “but the English created the famine.”

  Examples of British callousness were indeed thick on the ground. Some politicians welcomed the depopulation, which would, one cabinet minister’s agent promised, “give us room to become civilized.” Others said that giving food to soup kitchens actually did harm; if “large numbers would have perished of starvation,” one banking official reasoned, “the material relations of the survivors would have been re-established.”

  England’s defenders retort that although anti-Irish politicians said awful things they were ignored. In practice, the starving had to be massed if they were to be fed; delivering huge amounts of food to scattered families is not easy, even today. The exporters, moreover, were mainly Irish farmers who sold pricy meat and grain to buy cheap food for their families. Failure to accomplish the unprecedented, however dire the consequences, is not a moral lapse—or so the argument goes.

  No matter what degree of culpability should be assigned to Britain, the consequences of the famine to Ireland are indisputable: it broke the nation in half. At a million or more fatalities, it was one of the deadliest famines in history, in terms of the percentage of population lost. A similar famine in the United States today would kill almost forty million people. Only the famine of 1918–22 in the Soviet Union may have been worse. Within a decade of the blight another two million fled Ireland. Many more followed in subsequent decades, inexorably driving its population down. The nation never regained its footing. As late as the 1960s its population was half what it had been in 1840. Today Ireland has the melancholy distinction of being the only nation in Europe, and perhaps the world, to have fewer people within the same boundaries than it did more than 150 years ago.

  LAZY BEDS

  The Great Hunger left such a scar in Ireland that historians could barely bring themselves to look at it for more than a century. Since the 1970s, though, the famine has been the subject of hundreds of books and articles. In all the outpour, though, surprisingly little attention has been devoted to its cause, P. infestans—unfortunately, because the oomycete was the protagonist in the first calamity of modern commodity agriculture.

  P. infestans came to Ireland with surprising alacrity and overtook the country with puzzling speed. Ireland, an island nation, is eight hundred miles away from West Flanders. Between them are the North Sea and the Irish Sea. Blight spores are fragile: a single hour of exposure to the ultraviolet radiation in sunlight is enough to cut their likelihood of germinating by 95 percent. Even a light rain knocks them from the air. A widely cited ecological model suggests that as a practical matter they cannot surf the winds further than twenty to thirty miles. After tests in Wa
shington State, three scientists concluded that in perfect conditions—strong winds, cool temperatures, no direct sunlight or rain—blight spores might be able to move seventy miles, though fewer than 5 percent would survive. Except around Northern Ireland, the Irish Sea is wider than seventy miles. If the researchers are correct, blight spores could only have been blown to Ireland by traveling from southeast to northwest England, then floating over the North Channel to Belfast—a remarkable journey. (Technically, they are not spores but “sporangia,” the bags of spores released by blight, but I am ignoring this distinction for the moment.)

  Rain fell, sometimes heavily, on twenty-four of the thirty days after September 13, 1845, when the blight was first reported in Ireland. Yet despite the rain P. infestans swept across the country, striking with a remorselessness not seen anywhere else. Something about Ireland was uniquely vulnerable—but what? One part of the answer was the sheer number of potatoes, a fat target for the blight. Another part was the uniformity of the crop. According to Ó Gráda, the blight historian, about half of Ireland was dominated by a single, outstandingly productive variety: the Lumper. Many Irish lived in clusters of farmhouses called clachans surrounded by tightly packed, communally owned farmland. Encircled by clones of a single variety of a single tuber species, the clachans of western Ireland were among the most uniform ecosystems on the planet.

  Irish farmers for centuries had grown crops by cutting out blocks of sod, flipping them upside down, and piling them into long, broad ridges separated by deep furrows—“lazy-bed” farming, as the system was known. (The name may come from an occasional English epithet for the potato: the “lazy root.”) Typically four feet wide, the ridges loomed a foot or more above the furrows. They looked strikingly like wacho, the ridged fields in Andean societies. Like wacho, they were built in boggy soils; the ridges warmed up more quickly in the morning and retained heat longer in the evening than the surrounding flatlands, an advantage in cold places like the Andes and Ireland. Constructed from several layers of sod, the ridges represented concentrations of good soil; farmers could plant them densely, which naturally stifled weeds. Because the ridges were not plowed, they had intact root systems that resisted erosion; the roots also ensured that grass returned quickly after harvest, restoring nutrients.

  Unaware of these advantages, eighteenth-century agricultural reformers denounced the lazy-bed/wacho method as inefficient, an unproductive obstacle to modernization. Activists like Andrew Wight and Jethro Tull wanted farmers to release soil nutrients by deep, thorough plowing; to plant every possible bit of terrain; to charge the land with fertilizer (manure and then, when it became available, guano); to protect growing crops with ruthless weeding; and to maximize yields by efficient harvesting. Believers in technology, they viewed the newest factory-made harrows, drillers, and harvesters as God-given tools to accomplish these goals. Because these machines needed level land—they couldn’t climb up and down ridges—the lazy-beds had to go. On top of everything else, reformers said, the furrows between the ridges were a waste of space.

  Wacho occupied a swath of northern Europe that reached from France to Poland and included Britain, Ireland, Scandinavian countries, and Baltic states. As the new methods took hold after about 1750, they disappeared. Wacho had almost vanished from Ireland by 1834, when reform enthusiast Edmund Murphy took a cross-country “professional tour” between Dublin on the east coast and Galway on the west, taking “particular notice of the potato crop.” Seeing few lazy-beds in areas where they had once been ubiquitous, he crowed that they were “completely superseded.… Nothing shows the rapid improvement in agriculture which is at present extending in this country more clearly.”

  To examine the consequences of the shift to modern cultivation methods, Michael D. Myers, then at the University of Texas in Austin, experimentally created six fields in Northern Ireland: three lazy-beds and three of the level fields that replaced them. He discovered that the simple ridges and furrows created a complex geography, with surprisingly sharp temperature and humidity differences between the top of the ridge and the bottom of the furrow. Plant-disease specialists describe the temperature and humidity conditions that favor P. infestans in terms of “blight units”—the higher the number of blight units, the better the chance that blight zoospores on potato leaves will be able to germinate. Myers’s lazy-beds had roughly half as many blight units as the level fields. Blight spores were less likely to germinate in the comparatively warm, dry conditions atop the ridges. Because water drained into the furrows, it flowed away and beneath the growing tubers, carrying zoospores away from them. In addition, they had fewer noxious weeds and needed less fertilizer.7

  Many Andean peoples have long grown potatoes in parallel ridges called wacho (bottom, in Bolivia near Titicaca), a practice that has been shown to discourage fungal diseases by drying wet soil. Lazy-bed cultivation, as it was called in English, was common in Ireland (top, in northern Ireland in the 1920s) until the early nineteenth century. Recent research suggests the abandonment of lazy-beds helped potato blight race through the countryside, exacerbating the great Irish famine. (Photo credit 6.6)

  Murphy, denouncer of lazy-beds, took his professional tour because disease had been striking Ireland’s potatoes. This was in 1834, a decade before the blight; the diseases he was concerned with were viruses, bacteria, nematodes, and so on—ordinary pests that were adapting to the new crop. As the pests evolved, they caused crop failures; fourteen occurred between 1814 and 1845. (None of these incidents was anywhere as severe as the Great Hunger.) Myers, the University of Texas researcher, came to believe these failures were due in part to the abandonment of lazy-bed cultivation, which inadvertently fostered plant disease. (It is worth noting that the Andes did not have such widespread potato epidemics.) The blight was simply the latest and worst pathogen to take advantage of the new scientific agriculture: one kind of potato, on a terrain shaped for technology, rather than biology.

  The Great Hunger was the first truly contemporary agricultural disaster. Without the improvements wrought by modern science and technology, the blight would have had far less impact. Alarmed by the blight, governments in France, Belgium, Britain, and the Netherlands quickly asked biologists for help. But in its surge and sweep it was like nothing they had ever seen. During the next forty years, researchers attributed the blight to ozone, air pollution, static electricity, volcanic action, smoke from steam locomotives, excessive humidity or heat, gases from the recently introduced sulfur match, an emanation from outer space, various insects (aphids, ladybugs, tarnished plant bugs), and the potato’s own internal debilitation. Edward Hitchcock, a renowned natural historian at Amherst College, assigned blame to an “atmospheric agency, too subtle for the cognizance of our senses.” A few thought the cause was a fungus, but they were shouted down. No useful countermeasures were proposed. The plea for help went out to Science, but Science couldn’t answer.

  “WAR UPON THE BEETLES”

  In August 1861 beetles invaded a ten-acre garden in northeastern Kansas that belonged to a potato farmer named Thomas Murphy. His name was appropriate: Murphy, a common Irish surname, was also a slang term for potatoes. Murphy’s potatoes—Murphy’s Murphys—were overrun by so many beetles that he could barely see the leaves through the swarm of tiny glittering bodies. He knocked the insects from the plants into a basket, he wrote later, and “in a very short time gathered as many as two bushels of them”—remarkable, given that each insect was barely a third of an inch long. In a different context, perhaps, Murphy might have thought the beetle was beautiful, with its yellow-orange body and its forewings marked tigerishly with thin black stripes. But they were devouring his potato plants as fast as they came up.

  Murphy had never seen the beetle before its hordes suddenly attacked his potatoes. Nor had his neighbors who also were visited by it, or the farmers in Iowa and Nebraska whom it invaded that summer. The insect marched steadily north and east, expanding its range by fifty to a hundred miles a year, shocking po
tato growers at every step. It reached Illinois and Wisconsin in 1864; Michigan, by 1870. Seven years later it was attacking potatoes from Maine to North Carolina. The little insects swarmed potato fields in such profusion, according to one widely repeated story, that they stopped nearby trains. Their bodies covered the tracks in a layer deep enough to make the wheels slip “as if oiled, so that the locomotive was powerless to draw the train of cars.” Strong winds blew the beetles into the sea, from which they washed ashore in a glittering, yellow-orange carpet that fouled beaches from New Jersey to New Hampshire. Farmers had no idea where the creature had come from or how to stop it from eating their potato fields to the ground.

  The Great Hunger still a vivid memory, Europeans cringed to hear the reports of potato devastation. Companies produced thousands of small insect models to help farmers identify Murphy’s beetle. Germany imposed what may have been the world’s first-ever agricultural quarantine, against U.S. potatoes, in 1870; France, Russia, Spain, and the Netherlands followed suit. Great Britain, which had the most to fear, did not ban U.S. potatoes—it didn’t want to set off a trade war. Traveling in ship holds, the beetle kept appearing in European fields, only to be expunged. The First World War distracted governments from the task of monitoring insect movements. Seizing the moment, the beetle established a beachhead in France, then swept west. Today it occupies a swath of Europe that reaches from Athens to Stockholm. In the Americas its realm extends from south-central Mexico to north-central Canada. Many biologists fear that it will spread into East and South Asia, completing a round-the-world journey.