At 11,000 to 13,000 feet above sea level, just south of the equator, the land is steep and rugged--and dry. Clouds rarely mar the expanse of sky, and the views are crystalline, reaching far to other peaks, or down into the valleys where rivers snake like silver ribbons. In the United States, such heights are largely uninhabited places to which you would make short visits with appropriate gear. But subsistence farmers in the Peruvian Andes have lived at these altitudes for over 7,000 years. In this extreme terrain, they deal with prolonged periods of drought, eroding soils, and sweeping fluctuations in temperature. It's not uncommon for temperatures to drop from T-shirt weather at midday to below freezing at night, any day of the year. Nights can be so cold and dry that farmers can freeze-dry their harvest by leaving it in the open air.

"Despite these harsh conditions, Andean farmers developed one of the most important and unusual agricultural systems in the world," says Héctor Flores, who leads a team of researchers studying the highland farms. "Andean farmers developed a sophisticated system of agricultural terraces and irrigation systems, crop rotations, and soil conservation practices which even today are a feat of agricultural engineering. They also took advantage of how plants naturally adapt to environmental extremes, and domesticated crops that can be cultivated in overlapping vertical ranges. Maca, for example, adapted to grow at 14,800 feet, is probably the highest-altitude crop in the world."

The air in the highlands is thin, the light intense. Fifteen miles from one of the researchers' study sites, the city of Cuzco--once the hub of the Inca empire--serves as an acclimatization point for hikers before they start on the Inca Trail. At these heights, the slopes are too sheer for terraced agriculture, typified by the stairstep plots seen at lower elevations. Instead, the farmers cultivate small, fragmented plots scattered on the hillsides. "In one plot," says biological anthropologist Marleni Ramirez, "we were literally clinging to the side of the mountain."

Above: Penn State researchers, Peruvian scientists and farmers in the community of San Jose de Arizona. Penn State root biologist Héctor Flores is seated in front. Left to right: Andrea Meyer, Penn State undergraduate in nutrition; Marleni Ramirez, Penn State biological anthropologist; Flavio Cahuano, economics student from the University of Ayacucho; Carolyn Sachs, Penn State rural sociologist; Juan Yauri, community president at that time; David Dominguez, Penn State graduate student in agricultural and extension education; Tere Flores, Penn State graduate student in plant physiology; German Avila, agronomist from the University of Ayacucho (crouched); and two community members.

Depending on a plot's angle to the sun and altitude, ecological conditions can vary dramatically, creating a mosaic of microenvironments on a single farm. "To coax food from these microenvironments, Andean farmers took advantage of how plants naturally survive in challenging environments," Flores says, "namely, by developing underground storage organs. The farmers domesticated thousands of varieties of roots and tubers, which, together, are able to span the entire vertical range of agroecological niches."

Five hundred years ago, this system sustained 12 million people. "But today this area is one of the poorest in Latin America," says Flores. "Food security is uncertain and there are high levels of malnutrition. In a 1993 school census, roughly half of all of the children between ages 6 and 10 were found to be chronically undernourished. That number was higher--62 percent--for children from rural areas. In the 1980s, per capita food production dropped dramatically, partly as a result of policies that favored imports and the cultivation of introduced crops, a process which has been detrimental to native crops and traditional agricultural practices. In the last 20 years, the amount of land dedicated to the cultivation of native roots and tubers has decreased substantially. This is partly because people are under pressure to get income rather than keep the traditional system going."

Until recently, the highlands were remote, cut off from the modern world. But now, running water, electricity, and schools are coming to these communities. Roads that once were no more than glorified footpaths are being paved. People are devoting land to cash crops, or working off the farm. Because less time is spent with traditional practices, seeds have become increasingly difficult to obtain. Other complications include hundreds of years of accumulation of tuber viruses, which greatly diminish yields; the recent spread of an oca weevil, which infests up to 90 percent of one of the region's staple crops; and problems with rot in storage. The answers to these farmers' problems won't reside in a single discipline.

Right: Root biologist Héctor Flores and graduate student Tere Flores (no relation) examining the oca germplasm collection in the Penn State greenhouse.

The challenges of the Andes inspired a collaborative research project led by Flores and Rolando Estrada-Jimenez of the Universidad Nacional Mayor de San Marcos, Lima, Peru. They hope to improve the production, nutrition, and marketing of the important crops without compromising genetic diversity and traditional practices. Participating researchers span two continents and four universities. They include anthropologists, biologists, agronomists, and social scientists, as well as the highland farmers themselves.

"We wanted to begin documenting the vast body of knowledge that the farmers have of these crops," says Ramirez. "They know a lot about what they're doing. We can learn from them, and that knowledge can then be used to ask biological questions that will help address their concerns."

Agronomist Ramiro Ortega of the Universidad Nacional San Antonio Abad in Cuzco and Dr. Carlos Arbizo from the International Potato Center helped set up the project in two Andean communities, both above 11,000 feet: San José de Arizona in the Ayacucho region and Picol in the Cuzco region. "Until 1969, these communities were large haciendas," explains agricultural economist Steve Smith. "One was owned by the Catholic church and the other was privately owned. The peasant families worked the land. Then the government decided that the extremely skewed land distribution was no longer socially, politically, or economically viable, and the workers, forming small communities, essentially were given the land."

For a month each year since 1995, undergraduate and graduate students from Penn State have joined students from Peru to survey and document the farmers' knowledge of these crops in the two communities. The families are largely descendants of the original Quechua Indians that were incorporated into the Inca empire. Because many of the women and older people in the communities speak only the native language, Quechua, the Quechua-speaking Peruvian students were integral to the project.

The first step was to learn about the traditional production system. Smith worked with Carolina Trivelli, a graduate student in agricultural economics, on this aspect of the project. "A typical farm in the high Andes is very small," Smith explains. "It may have less than an acre of irrigated land, four or five acres of dry land, and a lot of common grazing land for llamas and sheep. The land holdings are often very fragmented, and span various altitudes and ecological zones. The farmers work mostly with hand tools and use no chemical pesticides or fertilizers."

To deal with poor resources, the highland farmers use a well-developed crop rotation system. The staple foods are potatoes and maize, complemented by the three "minor tubers," oca, ulluco, and mashua. They resemble multi-shaped, colored potatoes. After the potato, the oca is the second most important tuber crop and a staple food at 10,000 to 13,000 feet.

The irrigated plots at the lowest altitudes are reserved for cash crops--mostly onions. Potatoes and the minor tubers are planted in the higher rainfed plots, using an intricate crop rotation. "After resting a plot for three or more years to recover its fertility, the farmers plow, apply manure, then plant potatoes, their most important cash and staple crop," says Smith. "Because they have little manure or labor, the only time they put manure on the fields is the year they plant potatoes. The next year, they plant the minor tubers, which get the residual benefits from the rested soil, plus any residual manure. In the third year and maybe fourth year, they'll put in grain, often barley. Then they rest the soil and the cycle repeats itself again."

What's really different from farms in Pennsylvania is the diversity found within each plot. "They don't plant one variety of potato or oca," Smith emphasizes. "When they grow cash crops, they grow one variety. But they grow many varieties of each native crop." At one farm, up at 13,000 feet, Smith watched a farmer pull 27 different varieties of potato from her storehouse. "Within one field, they also may intermix beans or several tubers. This really reduces risk. If you have a disease or pest running through a field that is planted with one variety, you'll be wiped out--like what happened with the Southern corn leaf blight in the 1970s." At that time, U.S. growers were relying on corn hybrids with a relatively narrow genetic base. In one season, the blight wiped out 15 percent of the corn harvest.

Besides protecting against pests and disease, different plants complement each other. Beans fix nitrogen in the soil; other plants take it out. Deep-rooted plants break up the soil and bring up moisture. "This diversity is typical of peasant farming anywhere in the world," Smith says. "In tropical areas, you might walk into someone's backyard or field and think, 'What a mess! This is a jungle in here!' But it's not a jungle. It's a complex mixture of different plants, bush-es, and trees, each providing something for these people throughout the season. That's how they survive."

Because each plant has its own unique combination of vitamins, minerals, and elements, diversity also helps to maintain the health of the Andean people. "Ullucos are high in vitamin C," says Smith. "What other source of vitamin C would people get living at 11, 12, or 13,000 feet? We get our variety in the supermarket. They have to be able to produce that variety."

"We wanted to understand how the minor tubers fit into the highlander's diets and relate that to the nutritional status of the women and children," says rural sociologist Carolyn Sachs, who worked with graduate and undergraduate students doing the household surveys. Andrea Mayer, a student in nutrition, stayed with families all day, recording what they ate. "The people had enough to eat in the postharvest season," says Sachs, "but the women's diets had protein and iron deficiencies. Because the minor tubers help take care of those deficiencies, they would have to find substitutes if they stopped growing them."

Left: Plant pathology graduate student Jorge Vivanco analyzes proteins from the Andean root crop mauka.

Sachs and Mariela Bianco, a graduate student in rural sociology, studied how the farmers' socioeconomic status related to their choice of farming system and the growing of the minor tubers. "In many other parts of the world," says Sachs, "as soon as the socioeconomic status of a family goes up and they grow more cash crops for the market, they're likely to put aside growing the wide diversity of crops. But we didn't find what we expected. In these communities, the well-to-do families maintained a wide diversity of crops. Our best explanation is that they had enough access to land and labor to be able to grow the minor tubers, as well as their major staples.

"We also expected that as families became more connected with the cities, the growing of traditional crops would fall by the wayside. But we found a surprising continuation of the traditional indigenous crops, despite all these changes and pushes toward being more involved in the market and urban economy. The majority of people grow them because they like them. They're thought of as special foods."

The researchers did find that Picol did not have the diversity within species reported in other places in Peru. "What's likely to disappear is their access to the wide range of varieties," says Sachs. "This is partly because the oca weevil is damaging the harvests, but also because people are simply growing less of these crops than they used to. They're more involved in the market, their kids are going to the city to attend school, and they're working off the farm. The informal economy and exchange of seeds, although still operating, is less intensive than it used to be. But preserving diversity is something they want to do. It's something they care about."

Marleni Ramirez is interested in the farmers' rationales for preserving genetic diversity. Why do the farmers choose to grow certain varieties? What types of properties do each of those varieties have relative to production, storage, and cooking? "With oca, there's a pool of three or four common varieties which all of the families tend to grow," she says. "They're the sweeter, mealier, more tender varieties that can be simply baked. But these varieties have one drawback--the weevils like them, too. So the families also keep a second pool of varieties, which vary from family to family, that don't taste as good and require more complicated preparation but are more resistant to the weevil and last longer in storage. I'm interested in exploring the farmers' management practices used in seed selection, storage, and acquisition, which maintain these highly valued but highly perishable varieties. This will be very valuable information for future on-farm conservation programs.

"They have a tremendous appreciation for diversity," she adds. "Some of the students from Cuzco grew tubers at three different altitudes in the community to see how altitude affected growth. We had all of the tubers on the ground; I'd separated them into different varieties, and told the participating farmers, 'Here they are--distribute them among yourselves.' They took piles of tubers which were all a mixture. This is not what we're used to--we'd plant one pile of the yellow, one pile of the red, one pile of the white, and so on. But they wanted the mixtures. The Andean farmers really have an aesthetic appreciation for these tubers, which is reflected in their names. One oca has a beautiful blush--it's called Se–orita. A roundish one is called Big Belly. A long yellow mashua with purple streaks, which has medicinal properties, is called Tears of Christ. Some of the tubers are absolutely delicious, and their shapes and colors are incredible. One native potato has the texture of a mashed potato when you open it--it's like a cloud. They're so tasty you don't need to add anything else to eat them."

Ocas resemble long wrinkled potatoes colored white, yellow, pink, or red. Most are slightly acid and tart, but some are sweet enough to be eaten like fruits. They often are left in the sun for a few days to make them sweeter. The more bitter varieties are freeze-dried to remove their bitterness. Ullucos are bright and shiny yellow, pink, red, and purple. Unlike oca and mashua, which are sometimes considered "poor people's foods," ullucos are marketed in cities and are widely consumed. Mashua, tubers related to the nasturtium, taste more pungent--their flavor is reminiscent of watercress or radishes. Farmers like them because they are easy to grow and can be left in the ground until needed.

Ramirez has begun cataloguing the varieties, including their native names and the properties attributed to them. For instance, she learned that mashua is more pest-resistant than the other tubers; that's why the farmers can leave it in the ground longer. Also, some farmers intersperse mashua with potatoes in their plots to help prevent Phytophthora, a potato fungus. "This is the kind of information," she says, "which can provide leads for laboratory research."

The potential to obtain natural pesticides from these crops has particularly interested Flores. "The farmers already use their own biological controls against pests," he explains. "To prevent contact with the soil, they mound the tubers in storehouses over beds of straw. Over the years, they discovered that a variety of plants--some from the mint family--release compounds that repel insect larvae. So they dry the leaves of these plants and add them to the straw."

Jorge Vivanco, a doctoral student in plant pathology from Peru, joined Flores' lab to investigate potential biocontrol methods. While working at the International Potato Center in Lima, Vivanco discovered that a Ribosome Inactivating Protein (RIP) from an ornamental vine, four-o'clock, had antiviral properties against three important potato viruses and a viroid. This ornamental vine was, coincidentally, related to mauka, a little-known Indian root crop from the Peruvian Andes. Might this Indian root crop, he wondered, have a similar antiviral protein? "Mauka is used by the highlands people as starch for soup," says Vivanco. "Of all the Indian root crops, mauka has the highest amount of protein per weight unit and is also high in phosphorous and calcium. But this crop may be in danger of extinction. Presently, it's only being grown on about 200 acres of land."

Right: The Peruvian scientists have begun producing pathogen-free plants, as well as tiny, sterile in vitro tubers that are being field tested by the farmers.

Vivanco was able to identify a protein in mauka that is similar in size to the antiviral protein in four- o'clock. This protein turned out to have antifungal properties as well. Vivanco tested the protein extract on important fungal pathogens and found inhibition against Trichoderma reseei, a fungus used in antifungal bioassays; Rhizotonia solani, a potato disease; a Phytophthora species; Fusarium; and Trichoderma harzianum, or "green mold," a recent problem for the Pennsylvania mushroom industry. "Small amounts of protein extract inhibited fungi for six weeks in vitro," says Vivanco. "This is superb."

He also observed the fungal cells beneath the microscope to see what happens during inhibition. "The protein, which is an enzyme, is a potent inhibitor of protein synthesis, thus preventing fungal growth," he explains. "Basically, it chops the fungal cells to bits." He plans to test the extract with other potato fungi that affect roots or tubers. Because pesticides are very expensive in the Andes, this could lead to a cheap way to control diseases. Andean farmers potentially could grind up mauka roots and apply the extracts directly to the crops.

As Vivanco extracted and purified the protein, he found it was actually a complex of two proteins, tied closely together. He would like to separate the proteins and determine whether the biological activity comes from just one, or if they work in combination. From there, he hopes to clone the gene that codes for the protein. "Once we do that," he explains, "we can use transgenic technology to introduce it into the potato and get resistant varieties. Finding the gene that codes for this protein could stop the extinction of mauka."

Vivanco also wants to find out what kind of protein or proteins he's dealing with. If it is a Ribosome Inactivating Protein (RIP), like the protein in four- o'clock, it could have potential applications beyond this project, in anti-cancer or anti-HIV treatments. RIPs inactivate protein synthesis in cells, he explains, ultimately killing them. Alone, an RIP will act on all of an organism's cells. But to target a specific group, such as cancer cells, researchers can link an RIP to a specific antibody. This RIP-antibody combination is called an immunotoxin. So far, researchers have isolated 70 RIPs for potential use as immunotoxins, both antiviral and antifungal, but many of them are low in activity. They are very interested in any new sources of RIPs that have high activities.

Scientists involved in the Andean tuber project also are examining the nutritional content of the minor tubers. In Peru, they are analyzing vitamins and carbohydrates. At Penn State, Tere Flores, a doctoral student in plant physiology, is measuring the protein and amino acid contents of 20 varieties of oca. She will compare their nutritional content to those of other important tubers, such as the potato and sweet potato. Flores also tested crude protein extracts on fungal pathogens and found that the oca extracts, like those of mauka, inhibit the potato pathogens Rhizotonia solani and Fusarium oxysporum. "Now I'd like to know if that particular protein found in all the varieties is the one causing the inhibition," she says, "so I'm going to rerun the experiment using purified extracts." If Flores can trace the inhibition to a particular protein and obtain its amino acid sequence, researchers could then take the gene from oca, put it into the potato, and get a potato which is resistant to those pathogens.

Flores says native crops have a lot of potential if people pay attention to them and do research to improve their quality and yields. "We're working in some of the highest villages in the country," she says. "The farmers have to grow these crops--nothing else grows there. Some of these crops are even used medicinally. They have characteristics we don't know about. If people keep introducing non-native varieties, the native crops could be lost forever, as well as all the knowledge of their uses."

A germplasm bank serves as a repository of genetic resources. If a variety is lost, it potentially could be grown out and redistributed to the farmers. About 15 years ago, the project leader in Peru, Rolando Estrada, started an in vitro germplasm collection which now contains more than 800 different clones of ulluco, oca, and mashua. "In Peru, our research partners are beginning to characterize the actual extent of the genetic diversity in the collection," says Héctor Flores. The researchers have used techniques such as protein electrophoresis, which creates visual arrays of the tubers' proteins. If a tuber is genetically different from another, their protein patterns should look different. The researchers also are using molecular techniques such as DNA fingerprinting, which is the most accurate way to assess the extent of the diversity.

From Estrada's germ plasm collection, the Peruvian scientists have begun producing pathogen-free plants, as well as tiny, sterile in vitro tubers that are being field-tested by the farmers. "But we have to balance high-tech methods with simple techniques the farmers can use," Flores emphasizes. "One method the farmers are currently testing is propagation though cuttings. We found that when you let the tubers sprout, then take cuttings, the cuttings are free of the weevil."

Another low-tech method that works against the oca weevil was found serendipitously, during an ecophysiology experiment in which tubers were grown at various heights in the community to test their yields. "The tubers were grown at about 11 to 12,000 feet--the highest altitude at which oca and the other tubers can grow," explains Flores. "Within that 1,000-foot gradient, we saw huge differences in yield. The farmers usually don't grow the tubers at the highest elevations because they want the larger sizes. But we found that, although oca tubers grown at 12,000 feet are smaller, they are completely clean of the weevil. So we can maintain plots at the high altitude just to obtain weevil-free tubers, and the following season plant them back down low. These are very simple techniques that farmers can do to manage their own germplasm. Right now, the farmers are repeating the experiment to see if the result holds through the seasons."

As the city creeps closer and closer, the farmers deal with more market pressures. If they want electricity, water, or TV, they need cash. In Picol, many fields that were used for potatoes now grow barley for a brewery in Cuzco. The road through Ayacucho is being paved. Pressures are toward crop homogeneity and growing more imported crops.

"When you look at potatoes in particular," says Smith, "much of the past research focused on finding a variety that would improve yields and have resistance to a particular disease. If it worked, people would naturally adopt it and abandon the native crops. Market pressures also influence what farmers are growing. Consumers don't want to see bins full of multicolored, multishaped potatoes--they want consistency. As the farmers become more market-oriented, they need to be more concerned with what the consumer wants. Time also has become an issue in families. With more employment opportunities off the farm, people aren't going to spend as much time saving seeds, planting different varieties, and doing the whole range of things they do when their lives revolve around the farm. Education is becoming more and more desirable. If you want your kids to go beyond elementary school, you have to send them to the city and that costs money. So how do you make money? You put in more cash crops."

Agricultural economists involved in the project examined how improvements in minor tuber production might affect the economic and social welfare of the farmers, as well as the minor tubers' potential in the market. "Although ullucos are sold for a short time in the market in Lima and Cuzco, none of the farmers in our communities actually sell them," says Smith. "When we looked at the production system, we found the farmers lose up to half their crop in storage. Toward the end of the season, as the ullucos disappear from the market, their price really jumps. If the scientists could help to extend the storage period, the farmers could market the ullucos at double or triple the normal prices."

The researchers hope to continue exploring ways to help the farmers make money while preserving the traditional crops. "Because ocas are used mostly for subsistence and their market is not well-developed, we're looking into potential value-added products," Flores says. "Some of their starches might be good for soups, or industrial purposes such as adhesives or sizing for cotton clothes. Some of the sweeter, more beautifully colored ocas could be used to produce marmalades or jams. The farmers might be able to start local cottage industries, which could provide them with a source of income. Right now they barter their food, so any cash they get is significant."

Carolyn Sachs is comparing data from the two communities to see how modernization is affecting the traditional system. "Our first year in Picol, electricity came to the community," she says. "No one had trucks, but several families had TVs or radios. They now need more income to pay for electricity. Irrigation also has come to Picol, so they have begun growing vegetables. We suspect as they get more tied into the modern infrastructure, their traditional ways will change even more dramatically. As people become more urban, they often reject the ways of the countryside. In the cities, the indigenous crops often are thought of as lower-class foods. All over the world we see a greater diversity in the diets of rich people, but at the same time poor people are turning to macaroni and pasta, and their nutritional status is declining. One of the best things we can do in these communities is to help them see that as they get more money and resources, it's important not to reject these native foods which are so important to them."

"Different farmers have different aspirations and opinions about modernization," says Ramirez. "Some are critical about the paved road. They say, 'Our animals are going to get killed when we take them to feed on the higher ground.' Others say, 'We can take our products more easily to the market.' There are a number of mixed feelings about what it means to have cash. One man said, 'The money is used up very quickly but our crops will remain. It's better to make time to harvest and maintain your seeds because they will last over the long run.'"

Ramirez, Maggie Hedde, a Penn State graduate in integrative arts, and Mahia Maurial, a doctoral student in education, are putting together a photographic exhibition that explores the effects of modernity and progress on the maintenance of these crops and illustrates the various opinions of the farmers. "We have to be very careful not to do something that would go against preserving crop diversity," Ramirez says. "But in the end, it's the farmers who have the last word."

It is important that the researchers find solutions to the farmers' problems, which feed into the economic issues. "Often a scientist will say 'We can improve this,' but it's never been integrated into the system to see how it might fit," says Smith. "Likewise, a social scientist or economist might see improvement in the people's welfare if some change is made, but is that change even possible? That's what's good about this project. It's rare that you get all these disciplines working together from the beginning. We're not there to revamp their system, but to learn what their system's all about. It's a learning experience for us."

"A major goal of our program is to develop an independent research capacity in the Andes," says Flores. "This means, in part, training Peruvian scientists. So far, 10 graduate and undergraduate students from Peru and Latin America have been, or are being, trained. Field experience also is available each summer for Penn State students who wish to learn more about agriculture in the Andes."

Sachs also emphasizes the educational benefits. "One important thing that's come out of this project is the benefits it's given Penn State students," she says. "By working closely and living with the families in these villages, they've really begun to understand the complicated farming and cropping systems that are a way of life in other parts of the world."

Faculty and staff referenced in this article are Héctor Flores, professor of plant pathology and director of the Science, Technology, and Society program; Marleni Ramirez, research associate in food science; Carolyn Sachs, associate professor of rural sociology and women's studies; and Stephen Smith, professor of agricultural economics. Research discussed in this article is funded by The McKnight Foundation.