Hidden crops of the Andes

credit:I Manrique

Few plants grow above 4000 metres, so one root crop that thrives at such inhospitable altitudes is particularly cherished on Peru's cold steppe. Maca has long been an important food for highland Peruvians - it was enjoyed by the Incas, and is a common ingredient of the traditional pachamanca, where meat and vegetables are baked underground using hot stones.

Maca is just one of several root and tuber crops that originate from the Andes, but of which little is known outside the region. Potato, however, has had a very different fortune. When the Spanish selected this food plant to take back to Europe they could not have foreseen that it would come to be grown in nearly 150 countries, making it one of the world's most important crops.

What has made the potato so successful? And could other Andean roots and tubers have similar potential?

Destiny
According to Michael Hermann, an Andean root and tuber expert working with the International Plant Genetic Resources Institute (IPGRI), potatoes were destined to be the most successful of the Andean root and tuber crops. "There is a lot of evidence that potatoes were already the most popular crop in the Andes before the Spanish arrived," he says. "The attractiveness of potatoes precedes European contact." Their global success, Hermann thinks, lies in their bland taste and good texture, plus characteristics such as good storability, good genetic variability allowing adaptation to different environments, and high yields.

Left behind...
The native Andean crops, including the roots and tubers, declined when the Europeans introduced their own crops to the area. Faba beans, oats and barley, for example, were attractive crops to the highlanders and some chose to grow them instead. But the roots and tubers did not disappear, because of their cultural importance and comparative advantages on marginal land.

These crops are still important in highland diets, although some are more successful than others. Arracacha, oca and ulluco are the three most widely grown, and are eaten regularly by an estimated 15-30 million people. In contrast, ahipa and mauka are grown by no more than a few thousand farmers scattered across the Andes, and their survival beyond the next few decades is in doubt.

Researchers believe that the potential of these crops has not been fully realised in their native region. "They are unknown to the vast majority of the Andean people, and rarely reach the marketplace," says Hermann. They have so far mostly failed to penetrate urban markets, for example, because shelf-life and quality are often poor. And there is a certain amount of prejudice against 'Indian' foods, which are seen as 'rural' and 'backward'. Added to that is simple ignorance about their existence and culinary uses.

Seeking novel uses
Outside the region, several have had some success. Arracacha is also grown in Brazil and is increasing in importance. Oca has spread to New Zealand and Mexico as an exotic though commercially insignificant crop. But the most successful so far is edible canna, or achira, which has found a new market in Asia, particularly in Vietnam and China.

And this, says Hermann, is the key to a possible future for these crops outside the Andean region. "The potential for these crops to succeed outside their native range depends on novel uses. New demand leads to area and product expansion, and that new demand may come from uses that are unknown in the native area."

This is certainly true of canna in Asia, where it is used to make transparent or glass noodles, traditionally enjoyed in many dishes. Canna starch has proved to be easily extractable and to make good quality noodles, so that canna has now completely replaced mungbeans, the traditional raw material, for noodle making in Vietnam. Canna production in Asia now dwarfs that in the Andes, where there is a small starch extraction industry but less demand for the end product.

The root yacon looks set to follow a similar path. "Yacon is a low energy, high water content root, and this is probably why it has declined as a food crop in the Andes," says Hermann. "But there is increasing interest in yacon because of its high concentration of oligo-fructans, which we now know are beneficial to gut health. It has great potential as a diabetic food, and a health food." Maca, meanwhile, has found a burgeoning market as 'herbal viagra', though science has yet to verify its reputed aphrodisiac effects.

These new markets are in some cases leading to renewed interest in these crops in the Andes; farmers are responding to increasing demand for yacon and maca, for example. And while it is unlikely that any of the Andean root and tuber crops will challenge the potato in world agriculture, new uses mean that some, at least, may become more widely known and available.

Readers in Europe who would like to see some of these Andean roots and tubers need not go as far as South America. 'Hidden crops of the Andes' is currently an exhibit in the outdoor biome of the Eden Project in southwest England.