Publications /  The Potato, Treasure of the Andes
From Agriculture to Culture

I have dedicated most of my life to the study, exploration and genetic improvement of the potato. Among my many motives was the pride I felt when I discovered how important this native Andean crop has been in the history of humanity.

But my main impetus grew from the gradual understanding of how effective a weapon this tuber is against humanity's worst enemy: hunger. With dedication and effort, its contribution can be greater still. Just 500 years ago, few could have imagined that a staple crop of Andean peoples would become one of the most popular foods on Earth. Yet today it is the fourth most widely grown food crop in the world, after wheat, maize and rice. Apart from direct consumption, the potato has many industrial uses: it figures in the manufacture of starch, paper, and adhesives for textiles; it is an ingredient in low-fat processed foods, as well as in pastry and ice cream; and it is even used in cosmetics, pharmaceuticals and water purification. The potato belongs to the Solanacea family, along with other important plants such as tomatoes, eggplant, chili and tobacco. One of some 30 species of edible roots and tubers domesticated by the ancient inhabitants of the Andes, the potato is the only one of these that has taken on international importance.

THE POTATO ROUTES

Historically, the potato has been a crucial source of energy for many major societies. Accordingly, failed potato harvests have produced terrible socio-economic disasters. This was the case in nineteenth century Ireland, for example, where people based their diet almost exclusively on potatoes. Unfortunately, the potatoes planted by European farmers had been selected from a limited number of varieties exported from South America, and therefore had such a narrow genetic background that when late blight disease broke out in the 1840s, the crop was defenseless. Tragically, the Irish discovered that late blight had the power to destroy potato fields a hundred times faster than any other fungus, bacterium or virus. The result was the worst famine in the country's history.

In 1537 Spaniards first laid eyes on potato fields in the Grita Valley, province of Vélez, Colombia. The Spanish chronicler Pedro de Cieza de León recorded this sighting in his book,Crónica del Perú, published in Seville in 1553. He also made note of potato fields in Quito, Ecuador, as well as in Popayan and Pasto, Colombia. The first reference to the potato, however, is in a publication dated 1552, by Francisco López de Gomara - Historia General de los Incas.

No one knows exactly when the potato was brought to Europe, although historians believe this occurred in the latter part of the sixteenth century. Nor is it known from where the first potatoes were selected or the name of the person or persons who carried them to the Old World. For some time, it was thought that Sir Walter Raleigh and Sir Francis Drake had introduced the potato to England. But this is probably the stuff of legend, and there is no evidence to back up the claim. In any case, historical documents point to Spain as the probable port of entry.

The supporting evidence includes a 1565 notary's register from Tenerife, Canary Islands, which lists a shipment of locally produced potatoes destined for the Belgian port of Antwerp. Thus, potatoes had already been grown for some time on these islands. Further evidence dates to 1573, with the purchase of potatoes by Seville's Hospital de la Sangre.

Other documents show that in Belgium in 1587, the Prefect of Mons, Felipe Sivry, received potatoes as a gift from a friend of the Vatican ambassador. He had brought them from Italy where they had arrived via Spain.The following year, the Belgian official sent some potato tubers and a berry to the botanist Carolus Clusius, living in Vienna. In 1589, Sivry sent Clusius another gift, a watercolor of a potato plant that he had painted. The following year Clusius received two more illustrations of potatoes from the Swiss botanist Pierre Bahuin. In 1596, Bahuin published his book Phytopinax, which described the potato for the first time as Solanum tuberosum, a name still used today.

There is evidence that the potato reached France around 1600, thanks to the efforts of Bahuin. In 1613, the British took the tuber to Bermuda. From there it was shipped in 1621 to Virginia, in Britain's American colonies. The potato probably arrived in Ireland, where it was to prove so vital, around 1625. By the mid-eighteenth century, it had reached Scotland, Norway, Sweden and Denmark. And at the end of the nineteenth century, the potato was under cultivation in nearly all of Eastern Europe.

AMAZING DIVERSITY

The Andes are home to a great diversity of potato species. Among the potatoes cultivated today, Solanum stenotomum is believed to be the oldest, making it the "mother" of all cultivated species. Solanum tuberosum, however, is grown in more places on Earth than any other potato. Peru's Cordillera Blanca mountain range and the area around Lake Titicaca, in northwestern Bolivia, between 9º and 17º south latitude, feature the greatest genetic diversity in potato species. These are the only Andean regions to harbor the totality of cultivated species. Most probably, humans first domesticated the potato here around 7000 BC. Nine species of cultivated potatoes have been identified to date, and these are largely grown in the highland plains at altitudes ranging from 3,000 to 4,000 m. It is not unusual to find local farmers growing as many as four or five species on small plots of land.

The potato's biological diversity is not limited to the cultivated species, however. There is a complex group of around 200 wild and inedible species, found from the southern United States to southern Chile. Their great diversity comprises a wealth of traits that can be used by scientists to breed new pest or disease resistant varieties that withstand climatic stress. The Mexican species Solanum demissum, for example, is an important source of resistance to late blight; its genes are now found in most commercial varieties. Peru and Bolivia, meanwhile, have provided the frost-resistant Solanum acaule.

Wild potato varieties grow in diverse soils and climates, from the dry desert along the Peruvian coast to the inter-Andean valleys between altitudes of 2,500 and 3,400 m. Southern highland areas such as Cusco’s Urubamba Valley are particularly rich in wild species. These species are much rarer in cold areas such as the highland plain. By contrast, the warm and humid tropics, where vegetation is lush and temperatures range from 20º to 25°C, harbor some of the most scientifically valuable wild potato species. These include Solanum urubambae, which grows in tropical parts of the Urubamba Valley, and Solanum yungasense, cultivated near San Juan del Oro in the Tambopata Valley, department of Puno.

In the 1920s, the great Russian scientist Nikolai I. Vavilov launched the first major expeditions to unearth the diversity of cultivated plants. They led to the discovery of nearly a dozen cultivated potato species and various wild species. Throughout my career, I have studied Vavilov's work, as well as that of the botanists Sergei Juzepczuk and Sergei Bukasov. Indeed, I have spent more than 50 years walking in their footsteps: exploring, collecting and registering the extraordinary biodiversity of the Western Hemisphere. One of my most gratifying experiences came when I rediscovered a potato species first described in 1835 by the British naturalist Charles Darwin. It is worth pausing a moment to tell the story.

ON DARWIN’S TRAIL

In 1835, Darwin, aboard the HMS Beagle commanded by Captain Robert Fitzroy, sailed through the Straits of Magellan. Continuing north along the Pacific, they reached the Chilean archipelago of Los Chonos on 7 January and anchored in Low’s Harbor on Guayteca Island. During a week-long stay on the island, Darwin made the following entry in his journal: "The wild potato grows on these islands in great abundance, on the sandy, shelly soil near the sea-beach. The tallest plant was four feet in height. The tubers were generally small, but I found one, of an oval shape, two inches in diameter: they resembled in every respect, and had the same smell as English potatoes; but when boiled they shrunk much, and were watery and insipid, without any bitter taste". (Darwin, 1909).

This excerpt ran through my mind in 1969, when I entered a windy cave near Low’s Harbor. There, near the beach, I found the potato described by the author of On the Origin of the Species by Means of Natural Selection (1859). It was a wonderful moment, since nothing had been seen of this plant for more than 130 years. Perhaps for that reason, Professor Vadim Lechnovitch at the Vavilov Institute in St. Petersburg honored me by presenting the species to the scientific community as Solanum ochoanum. I have come to believe, however, that this potato had been cultivated and then grew wild, because it features the same chromosomes and a similar morphology as Solanum tuberosum. I surmise that fishermen or whalers transported the tuber from the mainland for their own consumption. In the nineteenth century, sailors ate potatoes to prevent scurvy.

Because S. ochanum has adapted to soils with high salt concentrations, this potato could prove useful in genetic improvement programs in parts of the world that suffer from high soil salinity. Today, samples of Darwin's potato are conserved in the World Potato Collection, a genebank maintained by CIP in Lima. The collection features thousands of potato samples, both cultivated and wild, many of which I gathered during my years of exploration.

ON BEHALF OF THE MOST NEEDY

My passion for the potato has not been limited to gathering and classifying plants. I have also worked to create new and improved varieties, taking advantage of the priceless raw materials offered by nature.

One of my first projects, when I began my career as an agronomist, was in Concepción, in Peru’s Mantaro Valley, at a government research center that specialized in cereal crops. The station conducted genetic experiments on different varieties of wheat. It was there that I woke up to reality. I said to myself, "Here we are, trying to introduce a foreign crop while we have one that has been domesticated in Peru for some 8,000-10,000 years, and one which plays such an important role in human nutrition".

I knew that in the highlands of Ayacucho, Apurimac, Cusco or Puno, people ate potatoes three times a day; for them, different types of potatoes were as distinct as ham and chicken were for other people. Andean people ate one kind of potato for breakfast, another for lunch and yet another for dinner. So it seemed to me that we ought to concentrate on the potato. Why try to compete with the wheat grown on the vast pampas of Argentina, or the prairies of the USA and Australia?

I knew that farmers in the Mantaro Valley complained about potato diseases and crops lost to frost. Sometimes they lost their entire harvest when plunging dawn temperatures devastated their plants. At the same time, I noted that although each farmer had preferences about which type of potato to plant, few chose the most disease resistant varieties.

Higher up in the mountains, however, it was a different story. There, farmers limited their losses by sowing from two to 50 different varieties in a single one-hectare plot. This resulted in improved harvests because a disease that damaged one type of potato encountered resistance in another. Using this strategy, the farmers ensured their families' survival.

Some farmers, however, particularly in the highland plains of Tarma and Huancayo, had succeeded in selecting and planting entire fields with a single variety. I remember one variety they called Chata Blanca (Spanish for "short and white"). I examined several farmers' fields, and although each tuber was indeed short and white, the flowers and leaves of the plants varied. Each farmer planted the variety he preferred, and each claimed higher yields.

I was just starting out, so my curiosity spurred me to gather a few varieties from the Mantaro Valley and the highland plain and compare them for two or three years. I concluded that each variety showed substantial differences in yield. In the late 1940s, when I carried out these early experiments, genetic improvement of varieties was still unknown.

Using recurrent selection, I produced a commercial potato variety I called Casablanca, named after the farm of Carlos Otero, who had helped me during my experiments on the highland plain of Tarma. Casablanca became the first variety to be widely distributed in Peru. In 1947, I spearheaded Peru’s potato breeding program with an ambitious hybridization plan that used selected native varieties as progenitors. This ultimately produced the first commercial varieties obtained through genetic improvement in Peru.

Potatoes produced through genetic improvement are like children: you name them, and in turn, they give you a great deal of satisfaction. I called one of my children "Tomasa" Condemayta after the lieutenant of eighteenth-century rebel Tupac Amaru. Her tragic death occurred on a farm that had until recently belonged to my family (and where I carried out experiments on several different potato varieties). In addition, Tomasa was the name of a nanny who was very dear to me as a child.

But my first child was called "Renacimiento", or rebirth, because I saw, from a scientific and technical standpoint, the advent of modern genetic improvement as a veritable rebirth of the potato. Both Renacimiento and Tomasa are still grown in many places in Peru, which I find gratifying. Yet, beyond their individual value, these varieties symbolize a conviction that has been the guiding force behind my work on this crop: the potato is one of humanity's most important weapons in the battle against hunger. My life's work has been an effort to help realize the potato's tremendous potential for the good of my compatriots and humanity.