Rachel Hebditch

It is the Year of the Frog, the National Year of Reading, the International Year of Planet Earth, European Year of Intercultural Dialogue and, wait for it, the United Nations International Year of the Potato.

It is the potato we are concerned about, one of the world?s great staple foods, which originated in South America where thousands of varieties are grown.

Potatoes are rich in carbohydrates with the highest protein content in the family of root and tuber crops. The protein is of fairly high quality with an amino acid pattern well matched to human requirements. They are rich in vitamin C ? a single medium sized potato contains about half the recommended daily intake - and they contain a fifth of the recommended daily value of potassium.

The farmers in Peru?s high Andes are among the poorest in the country with average incomes of under one US dollar a day. But they are sitting on something of a goldmine as the region is home to some three thousand varieties of indigenous potatoes. Some of the native strains look pretty strange as they are brightly coloured inside and out and come in all sorts of odd shapes. Many are disease resistant and were selected by the pre-Inca peoples for their good taste and high culinary qualities.

The potato, Solanum tuberosum, is an herbaceous annual that grows up to 40 inches tall and produces a tuber ? also called potato ? so rich in starch that it ranks as the world?s fourth most important food crop, after maize, wheat and rice. The potato belongs to the Solanaceae or ?nightshade? family of flowering plants, and shares the genus Solanum with at least 1,000 other species, including tomato and eggplant. S. tuberosum is divided into two, only slightly different, subspecies: andigena which is adapted to short day conditions and is mainly grown in the Andes, and tuberosum, the potato now cultivated around the world which is believed to be descended from a small introduction to Europe of andigena potatoes that later adapted to longer day lengths.

There are many organisations working to exploit the enormous diversity of species in South America. T?ikapapa, an initiative of the International Potato Center?s Papa Andina Partnership Program, is one of the finalists in a global competition for development projects. T?ikapapa is a marketing concept that links small farmers in the Andean highlands to expanding urban markets utilising potato biodiversity to create new market opportunities. It has won two awards already and the local farmers working with researchers have produced two new varieties of potato ? the Pallayponcho and Pukalliclla ? named after the poncho and a square shawl. Farmers in these areas do not use chemical fertilisers or pesticides or prepare the soil in a commercial way but rather till the soil with the traditional chaquitaclla. They plant a large number of different varieties that are suited to the particular environment to decrease the chances of crop failure.

The vast majority of the native species of potatoes are grown above 3,800 meters but because of climate change many are now victims of late blight. The work done by the community farmers and potato researchers to breed superior potato clones with resistance to blight will be used in other parts of the world.

The potato company, Greenvale, in the UK, has recently launched Mayan Gold, after working with the Scottish Crop Research Institute for fifteen years, to produce a variety that goes back to an original South American potato. This Institute holds the Commonwealth Potato Collection which has over 1,000 samples of wild potato collected by the British Empire Potato Collecting Expedition in 1938. From Lima, the party journeyed 9,000 miles through Peru, Bolivia, Argentina, Ecuador and Colombia, ending in Panama eight months later.

One of the members of that team was the late Professor Jack Hawkes who played an important international role in the emerging discipline of plant genetic conservation. It was recognised that plant genetic resources and potentially important genes were rapidly being lost in many parts of the world. Today crop germplasm is kept in gene banks across the globe which contributes to the sustainability of the world?s food supply.

The potato was probably domesticated between seven and ten thousand years ago in the Lake Titicaca region and the varieties were particularly suited to the quechua or ?valley? zone at altitudes of 3,100 to 3,500 metres. A frost resistant species was also developed that grew in the puna at around 4,300 metres. The Huari civilisation in the Ayacucho basin and the Tiahuanacu near Lake Titicaca, had sophisticated irrigation, terraced fields and raised field technology which resulted in yields estimated at 10 tonnes per hectare.

It was the ?people?s food? and played a central part with time being measured by how long it took to cook a pot of potatoes and land measured by topo, the area a family needed to grow its potato supply.

The Andean peoples stored potatoes in fresh and processed forms. Inca archaeological sites reveal extensive storage systems where temperature, moisture and diffused light were carefully managed to reduce spoilage. They also made chuno which was light, lasted for years and could be traded. The tubers were frozen at night, then warmed in the sun but shielded from direct rays, trampled to slough off the skins and soaked in cold running water for one to three weeks. Next the product was removed to the fields and sun dried for five to ten days. As the tubers dry they form a white crust, hence ?white chuno?.

The first potatoes to reach Europe arrived in Spain around 1570, unfortunately Sir Francis Drake did not get there first. They were viewed with suspicion and were rumoured to cause wind and leprosy and incite sexual desire and were given names like ?earth?s testicles? and ?Eve?s apple?. It wasn?t until the eighteenth century that the potato as a food crop in Europe began to take off and Henry Hobhouse was among the historians who believed that the potato encouraged the rapid rise in population that brought about the Industrial Revolution. The famines, harsh winters and wars in Europe during that century hastened the popularity of potatoes as they grew well and could be stored in the ground where they were less likely to be stolen by hostile armies.

?Late blight? phytophthora infestans first appeared in the Low Countries in 1845 spreading to England and then to Ireland where the poor farming population had no alternative foods to fall back on. The British government largely ignored the emergency and by the end of 1848 a million and a half Irish people had either died or emigrated.

Even though the potato was seen as the cause of the Irish famine, it has in general prevented famine with its high yields, brought about increased population growth and is now grown world wide. It allows even the poorest farmers to produce more healthy food with little investment or hard labour. Even children can easily plant, harvest and cook potatoes.

Paradoxically the potato as an anti famine food has today in our obesity obsessed age been transformed from a simple source of carbohydrate, protein and vitamins into a relatively expensive processed food carrying large amounts of fat known internationally as fries or if you are English - chips.