BUILDING A BETTER POTATO

Nestled some 13,000 feet up the Andes mountains of Peru, the village of Aymara is literally breathtaking. The chest heaves, the head throbs, the fingers tingle. The air is so thin and clear that distances deceive. Crags are etched in such detail that mountains appear closer, and the grassy slopes and cultivated terraces are an intense green.

Carlos Hidalgo, the 30-year-old community leader, is explaining to a visitor how Aymara villagers plant their potatoes observing traditions rooted in the Inca past. Every spring, they survey the stars of the Pleiades low over the northeastern horizon. If the constellation is bright, the villagers plant their crop early. If it’s dim, they wait a few weeks. The furrows are shaped according to weather predictions based on stargazing, the behavior of birds and insects, and even earth tremors. Since this was a wet year--as expected--the furrows were flattened. “That way the rainwater drains away and the potatoes won’t rot,” says Hidalgo. But neither astronomy nor naturalism prepared Hidalgo and his fellow farmers for the disaster of 1997.

That year, El Nino, the warm Pacific current that flows cyclically off the Peruvian coast, made its most devastating appearance in recent memory. In Aymara, it caused unusually high temperatures and heavy rainfall. Boulders that hadn’t budged in a geological era slid down mountains. Fields became steamy bogs, and cows sank to their hocks in mud. The villagers noticed that as their potatoes reached harvest time, the leaves were covered by a filmy, white mildew, and the tubers themselves turned black and soggy. “I lost maybe 80% of my crop,” recalls Hidalgo. “We barely ate that year.” Several elderly Aymara villagers died of diseases linked to malnutrition. The massive crop failure was caused by late blight, the same killer fungus responsible for the Irish potato famine of the 1840s that resulted in a million hunger-related deaths.

According to the Centro Internacional de la Papa (International Potato Center), a research institute headquartered in Lima, Peru, late blight losses in developing nations amount to about $3 billion a year. Nearly 15% of the Peruvian potato crop is destroyed annually by the fungus--and several times that in isolated areas. While cases of outright starvation are rare in Peru, blight-induced malnutrition causes death rates to soar among infants and aged people already weakened by respiratory and gastrointestinal ailments.

Rebecca Nelson, one of the potato center’s leading pathologists, finds the blight alarming, and she has been an ardent crusader of using genetically modified or “biotech” crops to combat the epidemic. “Blight is back and it’s bigger than ever,” says Nelson, an American who recently completed a research stint in Peru. “It has become the No. 1 potato disease worldwide.” One of the primary methods to combat late blight and other pathogens is by engineering new varieties of plants that need less fertilizer and pesticides. Potatoes have a potential yield per acre that is nearly twice that of cereals, making tubers a major weapon against global famine.

But plant geneticists are being denounced by environmentalists for creating biotech crops that purportedly could harm wildlife, morph into herbicide-resistant super-weeds and even pose dangers to human health. As the easiest of the major crops to modify genetically, potatoes have been at the heart of the controversy. “What right does some moralistic person from the United States or Europe have to deny biotech solutions to poor farmers in the Third World?” Nelson says.

A fine drizzle turns the air a misty gray and makes the dun-colored andean foothills on Lima’s outskirts look like slag heaps. The Peruvian capital, not a particularly attractive city any time of the year, is saddest during the rainy season. But it is a bittersweet period anyway for Rebecca Nelson, a 41-year-old recipient of a MacArthur “genius” grant for her work on plant pathogens. Within days, Nelson will be returning to the United States to head a larger research project after five eventful years at the potato center. Her house is in disarray, with her two boys, William and Benjamin, running wild through the rooms and garden, while her husband, Jonathan Miller, a freelance journalist, finishes packing boxes upstairs that will be picked up by the movers this same July afternoon. There are painful despedidas--goodbye parties--given in her honor by colleagues at the potato center, where she has been one of the most respected scientists in the center’s three-decade history of improving potato yields.

Nelson has supervised the release of some 40-odd disease-resistant potato varieties to poor farmers, but she’s not happy to leave behind ongoing lab and field experiments for dozens of other promising varieties. Adding to Nelson’s ambiguous frame of mind is the fact that her stay in Peru has coincided with a dramatic decline in the reputation of food scientists.

“We were regarded as saviors of the world,” says Nelson, a tall, thin woman with a halo of disheveled, curly hair around an almost adolescent face. “That’s not the case anymore. Now hunger is viewed as a complex poverty problem upon which agrarian research has relatively little impact. And then there’s the biotech controversy.”

When she addresses the issue, Nelson’s voice quickens and amplifies, her left foot jiggling on the armrest of a rattan easy chair in her living room. She cites the case of a bacteria gene implanted by potato center scientists into one potato variety to kill the deadly tuber moth. The new variety has almost eliminated the need for expensive and dangerous pesticides.

“Nobody talked about the huge mortality rate that pesticide spraying was causing among those poor farmers,” says Nelson. “They were dying like flies, and that to me was thoroughly unacceptable.” Nelson acknowledges that genetic modification is no panacea and that research can provide only part of the solution to the jigsaw of global food shortages. Moving lab results into the field is no easy task. Impoverished farmers with tiny plots of land are averse to taking on the risks of an unproven potato variety. There is also the fickleness of the marketplace. Consumers and wholesale distributors resist the tastes, textures, even the shapes and skin colors of new potato varieties. And there is no overseas market because most countries ban the import of unprocessed potatoes on the grounds that they are too likely to carry pathogens that could infect local crops. So the poor campesinos who accept new potato varieties and technologies tend to remain subsistence farmers, at least grateful if they can cut their costs.

The complex layers of farmer resistance to new potato varieties may be hard to peel away, but they can be easily glimpsed in Aymara, a village of less than 100 families about 200 miles southeast of Lima. On a bright, crisp morning, a trio of middle-aged men, wearing thick wool sweaters and caps and chewing wads of coca leaves to ward off the cold, are stomping on small piles of thawing potatoes. Jorge Romero, at 53 the oldest of the three, explains that the potatoes had been left on the field to freeze overnight. Now that the sun has softened them, the tubers are being crudely but efficiently crushed and peeled by bare, calloused feet. The mush will then be placed in a nearby well and left to ferment for 15 to 20 days. Finally, the potatoes will be sun-dried into a mealy preserve, known as chuno (CHOON-yoh).

Five centuries ago, the Inca warriors who were Romero’s ancestors survived on little else but chuno during their months-long battle marches. Romero and his fellow Aymara villagers prefer to eat it on special celebratory occasions, mixed in hearty stews with egg, meat and cheese.

“But we set aside most of it for emergencies because chuno can last up to 10 years,” says Romero, his unshaven, sunburned cheeks bulging with coca chaws. By emergencies, Romero means those years when crops are ravaged by pests. In the early 1990s, the potato center introduced pest controls in Aymara to cope with the main local predator, the Andean weevil. Multiple defenses were created against the insect. New potato varieties, less appetizing for the weevils, were planted. Fields were circumscribed by shallow ditches doused with small quantities of pesticide and bordered with plants whose leaves contained natural toxins against the weevils. Finally, the harvest was placed on plastic sheets, a simple barrier that prevented surviving weevil larvae emerging from diseased potatoes from burrowing into the ground to mature and attack a future crop.

The main benefit to Aymara of the new varieties--some of them genetically modified--has been the sharply reduced investments in costly pesticides, allowing cash to be spent elsewhere. While the village is mired in poverty--it still has no electricity, phones or running water--most men now wear factory-made shirts, pants and work boots. (Women, though, continue to dress in traditional billowing skirts, woolen stockings and leather slippers made at home.) Even these limited gains were threatened by the near famine of the late blight outbreak in 1997. “You go around the Andes and see so many destroyed fields and you want to do something about it,” says Nelson. “So as far as I’m concerned, blight is the most obvious plant pathogen for me to get involved with.”

Nelson was born into scientific research. Her parents were researchers at the National Institutes of Health in Washington, D.C. As a kid, Nelson dissected road kills in her bedroom while her schoolmates were playing field hockey and baseball. After graduating from Swarthmore, she completed her PhD at the University of Washington in Seattle--though the degree was in zoology, not plant pathology, her chosen career. “I’m proud of the fact that I’m totally untrained for what I’m doing,” she jokes.

Qualified or not, Nelson landed a job in 1988 with the International Rice Research Institute in the Philippines to study rice blast, a major crop disease. From there she moved to Peru in 1996 to head the late blight program at the potato center. An internationally funded institute, the potato center was already in the midst of prolonged soul-searching--that continues to this day--about how to best approach its mission of improving potato yields and the livelihoods of farmers. Like every food research program, the potato center was being forced to battle for public and foundation funds with other worthy, scientific causes, especially environmentalism. “Until recently, our entire focus was on increasing productivity and giving the world more to eat,” says Fernando Ezeta, the potato center’s regional representative for Latin America. “But over the last decade, there has been a growing global concern over the environment. So we are competing with ecological researchers for the same financial resources.”

To woo potential donors, the potato center is being pressured to behave more like a private enterprise and demonstrate the “profitability” of its research projects. Potato center projects have been whittled down from more than 30 a decade ago to 13 today. Each project is ranked in terms of its probability of scientific success, dollars saved or gained per acre, and the poverty level of the farmers it benefits, among other factors. By these criteria, the late blight program, under Nelson’s direction, has been deemed the top research project, meriting the largest single portion of the potato center’s $24-million budget in 2000. Economic returns are projected at more than $250 million between 1998 and 2015.

These returns will not be guaranteed by scientific research alone. Bureaucratic battles must be fought and won within the potato center before new potato strains can be distributed to farmers. Trusted intermediaries must be found to convince farmers to experiment with new varieties. And the farmers must be seduced into becoming active partners with potato center scientists in their efforts to propagate more productive, pest-resistant tubers. These various tasks can force Nelson into wearing a lab coat, a field poncho and sometimes, metaphorically at least, a helmet. While she views herself primarily as a scientist, her success is equally dependent on her managerial skills.

Past experience has demonstrated to Nelson that there is no silver bullet, no single gene that can be counted upon to permanently resist late blight. “What usually happens is that if we try to combat a disease by concentrating on a single, major gene, we might get a potato variety that offers resistance for a few years and then fails,” she says.

Instead, her lab tries to isolate several genes, each with small effects on late blight but acting together to offer a more complex, lasting resistance to the disease. The lab workers might fish these genes directly out of the potato center’s huge potato seed collection and plunk them into potato varieties marked for field experiments. “That’s bioengineering using genes from the same species,” says Nelson. “But I’m also in favor of genetic modification using genes from other plant or animal species because they offer us additional options.”

The next stage is getting the potato center’s plant breeders on board. Breeders tend to represent the old-school approach to scientific research, displaying more caution than a molecular biologist like Nelson. They focus their efforts on gathering wild potato species, crossing them with domestic varieties, and constantly building up the tuber seed stocks. They tend to withhold new potato strains out of fear they might fail in the field. With the breeders in charge, it was taking the potato center about 20 years to move a new potato variety from lab to land. So, among old-timers, there has been a good deal of resentment ever since Nelson appeared on the scene with a commitment to drastically cut down this time lag.

“I just want to get as many potato varieties off the shelf as quickly as possible and let the farmers decide if they want them or not,” says Nelson. But making the initial contacts with rural communities can be daunting. The Peruvian government has no agricultural extension service. The potato center, with roughly 100 scientists in Peru, doesn’t have the manpower to find and woo campesino leaders. In the end, CARE was used as an intermediary, taking advantage of that global group’s contacts in the Peruvian hinterlands.

CARE had been running community development programs for several years around Cajamarca in the northern Andes, where late blight was rampant. And in 1997, CARE introduced Nelson and her potato center colleagues to local farmers. Groups of up to 25 campesinos were invited to join potato center field schools that met once a week over the three-to-four-month period of a potato cycle from planting to harvest. “The idea was to get them to understand the life cycle of late blight in order to break it,” says Nelson. “Farmers know the connection between weather and late blight. But they aren’t aware of the microbe world.”

At the field schools, campesinos were given disposable plastic bags--mini-hothouses--to be used to quickly grow fungus-infected potato plant samples. Once the fluffy white film of late blight developed on the budding leaves, it was scraped off and viewed under rudimentary $15 microscopes that participants shared. “They could see that it’s not chaos down there, but actually beautifully symmetrical spores that look like tiny lemons,” says Nelson. “For the first time, they were seeing the causal agent, and they were excited.”

Simultaneously with these laboratory classes, the farmers were asked to plant small patches with a dozen varieties of experimental potatoes developed by the potato center in the hope that at least some of them would prove resistant to late blight. “I was praying it would be a wet, warm year, which would create ideal conditions for late blight,” recalls Nelson. “We would have had a very dull outcome if it had been a dry year.” She got more than she wished. El Nino brought record rain and heat. The Cajamarca landscape was churned into mud. On mountain slopes, crops were washed away, and many of the surviving potatoes were attacked by late blight. But the disaster allowed the farmers to witness the power of the new, resistant varieties.

Two in particular--the yellow-skinned Amarilis and the red-skinned Chata Roja--were so successful against blight that the farmers decided to plant them on their own plots the next year, without awaiting further crop tests. A year later, the new potato strains were cultivated throughout Cajamarca by farmers who had been skeptical about the potato center program. “Chata Roja was the real favorite because it had a very high yield besides being resistant to blight,” says Nelson. Incredibly, the potato center’s overly cautious breeders had developed Chata Roja 17 years before, but kept it on the shelf all that time because they felt it needed more lab tests to prove its resistance. “Sometimes, you just have to take risks,” says Nelson. “If you get farmers involved from the beginning, you won’t have to worry they’ll walk away if a strain fails. Nothing is going to be permanently successful against blight, anyway.” She cites as an example a genetically modified potato variety called Canchan, which gained popularity throughout Peru because of its good taste, high yield and resistance to blight, but eventually became so vulnerable to the disease that it has been dubbed “Ranchan”--the colloquial name for late blight.

Ultimately, the success or failure of a new potato variety depends on its acceptance by consumers--or, in practice, the wholesale marketers who distribute the many potato strains to retail markets and food stands. The largest wholesale market in Peru is La Parada, located on the outskirts of Lima. Sprawling over 100 square blocks, La Parada sells 1,200 tons of potatoes every day from 3 a.m. to noon.

The potatoes pour into La Parada overnight from the wind-swept Andes, the baking coastal plains and the rain-lashed Amazon highlands. Traffic jams on the periphery of the wholesale market are stultifying. Trucks disgorge their loads several blocks away from the main entrance, where an army of porters carries the produce to more than 300 wholesale stands. “There’s a lot of wastage because so much produce rots or gets eaten by vermin,” says Fernando Cilloniz, president of a management consultancy and a leading expert on food distribution. “La Parada’s vendors have little incentive to correct these problems because they know they have no real competition.” A decade ago, Cilloniz was predicting that modern supermarkets would largely replace La Parada. But years of economic stagnation have discouraged investment in supermarkets, which account for 20% of the food distributed in the country.

Rebecca Nelson visits La Parada one Friday at dawn, partly out of curiosity over which potato center-bred potato varieties, if any, are on sale, but mainly because her younger son, Benjamin, wants her to pick up as many different potatoes as possible for his show-and-tell class later that day. La Parada is notorious for crime, and Nelson arrives without jewelry or a watch and is accompanied by a bodyguard. The real threat, though, is getting bowled over by porters rushing in every direction. Swarms of these small, muscular men trot through the crowded alleys with almost unbearably heavy 80-kilo (176-pound) bags of potatoes. Their backs are bent to a parallel plane above the ground, their faces fixed in a sweaty grimace, and their downcast eyes unable to search out more than a few feet ahead.

“Pasando! Pasando!” (“Coming through!”) they groan. This is work for the desperate: recent rural migrants, ex-cons, youths with facial deformities that render them unemployable elsewhere. They last only a few years before hernias, slipped discs and broken backs force them into other means of survival. Nelson’s contact at La Parada is the biggest wholesaler, Ines Talavera, a woman known as La Reina de la Papa, or the Potato Queen, and portrayed in the local press as a mafiosa. According to Cilloniz, the management consultant, Dona Ines’ power is exaggerated and her notoriety undeserved.

“She controls maybe 3% of the $120-million annual turnover at La Parada,” he says. “And she is a person of excellent character. But you know how people love to think that the world is run by evil conspirators.” In fact, Dona Ines--as everybody calls her--projects a mix of competence and fragility. A small woman close to 70 years of age and with a paralyzed right arm, she sits on a chair placed on a raised wooden platform to better view the squads of porters with their arriving booty. Her cell phone rings constantly with the latest wholesale market prices and with purchase orders from restaurants. Most of her clients, though, are small vendors who personally come for the potatoes, which they will peddle at street stands throughout the city.

Dona Ines sells some 20 different potato varieties. Nelson recognizes some potato center-bred strains, including Canchan, the formerly miraculous, bioengineered potato that has recently lost its resistance to late blight. But other varieties are a total mystery to Nelson. “What’s that?” she asks Dona Ines, pointing to a 6-inch-long, curving oval tuber. “Lengua de buey” (“Ox tongue”), replies the Potato Queen, using its perfectly apt nickname. Nelson observes that for the most part, the potatoes on sale are traditional varieties, the same ones that have dominated the market for decades. “That can’t be helped,” says Dona Ines. “I offer what my clients want. I don’t see any great demand for more varieties.”

Certainly Dona Ines has little use for most of the dozen potato varieties being harvested that same week at Aymara, the village high up in the Andes. On a gently sloping two-acre plot, a score of men and women are helping Carlos Hidalgo, the community leader, dig up his potatoes. Some varieties have nutty flavors, others are almost as sweet as yams, and a few are as rich as egg yolks.

“We eat potatoes three times a day,” says Hidalgo. “They have so many different tastes.” Hidalgo wants his two boys, 6 and 4 years old, to become farmers and stay in Aymara. But he thinks that will only happen if new, more disease-resistant varieties can be introduced that will break the cycle of feast and famine. Though Hidalgo continues to believe in the power of stargazing and natural phenomena to foretell harvests, he hopes to enroll in a potato center field school on pest control.

“I want to learn about those microbes,” he says, squinting an eye into hands curled into the shape of a microscope. Hidalgo’s seemingly contradictory embrace of the traditional and the modern doesn’t surprise Nelson. “These farmers are open to new ideas as long as they can be shown to work,” she says. “I never came across farmers who acted out of irrational superstition. Still, there are things that we scientists just don’t get.” Last year, when an earthquake devastated the region around the southern Andean city of Arequipa, farmers elsewhere in the mountains predicted--correctly--that there would be heavy rains even though the wet season hadn’t yet started.

“I don’t know any reason why there should be a connection,” says Nelson. “My maid tells me the wind blows funny when there’s about to be an earthquake--and she’s right. I’ve heard of villages where dogs howl and cats meow when someone is about to die. And I’ve seen enough strange things happen that I just say to myself: ‘Here, this is true.’ ”