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

The Dutch are among the world's great potato lovers. Potatoes are a cornerstone of the Dutch diet and a pillar of the country’s economy. In Amsterdam, people stand patiently in line to be served at special French fry shops.

In the countryside, potatoes anchor almost every meal. Yet it took me, a Dutchman by birth, many years to understand their attraction. I never ate potatoes as a child. In Indonesia, where I grew up, they simply were not available. I was raised, quite happily, on rice. When I was a young man I immigrated to Canada. Canada, like the Netherlands, is a great potato power, but I remained unmoved by the tuber's charms. As a graduate student I wrote a paper on potato production in the Canadian province of Saskatchewan, but my heart belonged to the fluffy white grains I had relished as a boy in Asia.

It was in South America in the 1970s that I began my conversion into a potato partisan. I worked as an agronomist in Colombia, analyzing the broad mix of activities pursued by farmers in one of that country's poorest districts. I couldn't ignore the data: potatoes were more efficient, more nutritious and more profitable than any other staple crop. They were unparalleled as producers of food, jobs and cash - and the farmers knew it. The potato, I realized, was ideally suited to places where land was limited and labor was abundant - conditions that characterize much of the developing world. Although I was destined to work for years on rice-based farming systems, I never forgot the argument for potatoes.

Numbers back up that argument. As an agronomist, one of my central interests is a plant's "harvest index." This is the ratio of the weight of usable food to the weight of the entire plant, and provides a good gauge of a crop's efficiency. The potato typically has a harvest index of 75-85 percent. This means that under one-fourth of the plant material produced by sunlight, water, nutrients, labor, and other inputs is wasted. Compared with other crops, that is an astounding figure.

I remember sitting in a seminar years ago in which a potato scientist boasted to a group of my fellow rice scientists about his crop's advantages. My colleagues were justifiably proud of the Green Revolution changes they had helped bring about - changes that had altered the basic architecture of the rice plant and dramatically boosted yields across Asia. The visitor was less impressed. By increasing the number of grains per plant while reducing the weight of stalks and leaves, he said, the Green Revolution had succeeded in raising rice's harvest index from 35 percent to 55 percent. It would take another revolution to bring it even close to potato. There was grumbling in the room, but not from me. I had seen first-hand what the potato could do. Amid all the talk of "miracle grains" the humble spud seemed miraculous indeed.

Today I believe more strongly than ever in the potato's promise. I see it everywhere I go. When I first visited Bangladesh in the famine-plagued 1970s, I saw virtually no potatoes. Now the country is a potato powerhouse. The potato is growing by leaps and bounds in some of the poorest parts of Africa, while China has become the world's leading potato producer. I confess that when I return to Indonesia, my childhood home, I still choose to eat rice. But now potatoes are always an option. In fact, by the late 1990s, Indonesia was producing nearly half as many potatoes as Peru.

TUBERS OF CHANGE

The potato could not have come to the developing world at a better time. Over the next two decades, the world’s population is expected to grow by an average of more than 100 million a year. More than 95 percent of the increase will occur in developing countries, where pressure on land, water and other resources is already intense.

Feeding billions of people under increasingly difficult conditions will not be the only challenge. Agriculture will remain the most important income generator for most of the planet's poor. Indeed, one of the great paradoxes of our times is that the majority of the world's hungry are themselves the planet’s food producers. The reason for their hunger is not just low productivity, but also a lack of money with which to buy other essential foodstuffs. Attempts to boost family incomes and stimulate economic growth in the rural areas of developing countries will inevitably depend on improving the efficiency of agriculture and agroindustry.

But agriculture is not just a rural concern. Affordable, nutritious food is the most important lifeline for billions of low-income city dwellers, many of whom have fled the countryside because they can no longer support themselves by working the land.

The point of all this is simple: where agriculture is weak or inefficient, all of society suffers - from overcrowded cities, soaring health costs, environmental degradation, even crime and civil war. The world may be getting more urban, but food production is still at the core of nearly everything human beings do.

Since the Green Revolution dramatically boosted cereal yields in the 1960s and 1970s, grains such as wheat, rice and maize have become the standard measure for food production worldwide. Yet time has taught me that roots and tubers can be much more efficient than cereals. As raw materials for animal feed, processed foods and a range of industrial products, they are excellent sources of income and employment for cash-poor farmers and rural communities. Roots and tubers will never replace grains in the world's food basket. Yet where food security and poverty reduction are the goals, they can and should be a major part of the mix.

The potato exemplifies this potential. It is high in energy and rich in important nutrients. It commands a competitive price nearly everywhere it is sold. And, although science has much to offer in helping the crop realize its potential, the potato does not need a Green Revolution. Using existing technology - such as eliminating diseased seed, or planting improved varieties - farmers could boost potato yields by proportions that would be unthinkable in grains. In China, for example, researchers estimate that a 30 percent jump is within reach. The impact of that increase would be staggering.

THE GREAT LEAP

Since the early 1960s, the land area planted with potatoes in developing countries has grown faster than that planted with any other major food crop. During the first two decades of this century, production of potatoes in the world's poorest countries is expected to continue increasing at a higher rate than production of rice, wheat or maize. An unprecedented explosion in demand will accompany this increase in production. By 2020, the developing world’s appetite for potatoes will more than double what it was in 1993.

How will that appetite be satisfied? About half of the increased production will result from an expansion in the land area devoted to potatoes, mainly from the displacement of less competitive crops or the planting of potatoes between the growing seasons of other commodities. The other half will have to come from increased yields and reduced losses. Fortunately, no major crop is as promising in those regards as the potato.

The average world potato yield at the start of the twenty-first century is 16 tons per hectare. That number, however, masks huge variations among countries. Yields in some parts of the Netherlands exceed 100 tons per hectare; in Argentina yields have topped 70 tons per hectare. Yet farmers in Bolivia harvest just 6 tons per hectare, on average, and in Uganda and Malawi yields are 7 tons. Given differences in climate and topography, not every country will be able to average more than 40 tons per hectare, as the Netherlands does. Yet there is tremendous room for improvement.

The gap between actual and potential yields is caused mainly by biotic constraints (such as diseases and pests) and an insufficiency of inputs (such as irrigation water and fertilizer). Low quality seed also hampers production in many places, and post-harvest losses reduce the amount and quality of potatoes that find their way to market. Low investment levels in agricultural research, extension and rural infrastructure often exacerbate these problems. Boosting potato production to meet the surge in demand will require a Herculean effort, but I am pleased to report that important progress is being made.

MAKING IT HAPPEN

Solutions to many of the potato’s problems can be found in the crop’s own impressive genetic diversity. This diversity has come about naturally, in part as the potato has evolved, and is also the product of thousands of years of breeding by farmers and scientists. Forward-thinking researchers have worked hard to collect and characterize this crop’s genetic wealth, preserving it in modern climate-controlled conservation facilities and in cultivated genebanks. The results of their efforts are felt every day, as scientists use the genetic materials from hundreds of traditional, wild and modern potato varieties to fashion improvements ranging from drought tolerance and pest resistance to better digestibility and flavor.

One of the most promising areas of improvement is in breeding for resistance to diseases. Late blight is widely known for its role in the great Irish famine. Today it is among the most damaging crop diseases on the planet, costing farmers more than $3 billion a year in lost harvests and fungicide expenses in developing countries alone. Some researchers estimate that late blight cuts global potato yields by as much as 15 percent.

New strains of late blight’s causal pathogen are emerging and migrating to all major potato-growing areas. To make matters worse, these strains have been acquiring resistance to some of the most popular fungicides. But help is on the way. Breeders have recently produced a number of locally adapted varieties that show durable resistance to late blight. The hope is that this sort of genetic protection will replace fungicides as the cornerstone of late blight management.

Viruses also figure among the potato's most threatening enemies. Carried by insects or by infected seed, they are notoriously hard to detect and control. Scientists have made huge strides in virus management, however. A major advance has been the development and dissemination of tests that allow seed producers to identify and eliminate infected seed potatoes. If the seed is healthy, the chances are much greater that the crop itself will be. Virus resistance is also bred into many popular varieties.

Bacteria present another challenge, especially for developing-country potato growers. A disease known as bacterial wilt affects about 1.5 million hectares in more than 80 countries, frequently traveling to new areas with shipments of infected seed. CIP has refined and distributed a powerful test to assist seed producers and national plant protection agencies in detecting the bacterium that causes bacterial wilt. Because the pathogen can remain dormant in the soil or in plant materials for long periods, detection is a vital step on the road toward control. As with other potato diseases, no single technology is expected to solve the problem, but a range of measures taken by farmers and seed producers (including crop rotation, and detection and disposal of infected seed) should go far in reducing the damage. Controlling bacterial wilt will be one key to making the potato a reliable crop in many parts of tropical Asia, Latin America and Africa.

Insect pests also take a large bite out of yields, attacking foliage and tubers and acting as vectors for diseases. Recognizing that pesticides can often do more harm than good - killing beneficial insects and posing health and financial risks to farmers - scientists are working with extension agencies and other partners to refine and promote integrated pest management (IPM) for the major insect pests of the potato. IPM gives farmers the information and technical tools they can use to manage pest problems holistically. An IPM program may include insect traps, pest-resistant potato varieties, biological controls and the judicious use of chemical pesticides.

The effectiveness of any IPM program ultimately depends on farmers' ability to make well-informed decisions. This makes grassroots education a must. One exciting development in this area is the spread of "farmer field schools," where small-scale producers meet regularly to familiarize themselves with scientific principles, share tips on integrated management strategies, and test new potato varieties and breeding lines for their effectiveness under local conditions. Field schools are founded on the belief that pests, diseases and other production constraints are highly variable, and that effective management inevitably rests on the solid knowledge base of those people whose livelihoods depend on a healthy crop.

IPM is one area of technological innovation where twenty-first century science and the real world of low-income potato farming can come together in creative ways. For instance, using inexpensive plastic jugs and string, farmers can assemble insect traps that use synthetic pheromones to attract pests. Another IPM technique employs farmyard birds to eradicate destructive larvae; farmers are encouraged to stage contests between the village chickens - the bird that eats the most larvae wins. As IPM gains acceptance, farmers can expect to cut both costs and losses, as well as to protect their health and that of consumers.

Despite the advances in potato management and breeding, much work remains to be done to reduce the crop’s dependency on chemicals. Every year, hundreds of thousands of potato farmers and contract laborers suffer the severe health effects of pesticide poisoning. Millions more must bear the financial burden of expensive chemicals or risk catastrophic losses. Much of the research conducted in the next two decades will be aimed at addressing this critical problem.

The goal is not to produce magic bullets or miracle potatoes - needs and conditions are too varied for that. Crop improvement is a constantly evolving process, requiring close collaboration among researchers, policy makers, regulators, seed producers, extension workers and farmers. Knowledge is increasingly becoming the most powerful of all management tools, helping to meet farmers’ and researchers’ growing needs for reliable, site-specific information.

Geographic Information Systems (GIS) research acknowledges that fact in an especially eloquent way. GIS brings together data from a wide variety of sources - ranging from censuses and economic surveys to climate studies and field experiments - to produce maps and other user-friendly reference materials. An example of a GIS product might be a map of frost risk for low-income potato farmers on the Andean altiplano, or tables projecting the effects of temperature, leaf moisture, soil type and potato variety on the incidence of late blight disease. GIS helps scientists and policy makers come to grips with the great diversity of biological, physical, and socio-economic factors that bear on potato production.

Another encouraging development is found in "true potato seed" (TPS) technology. TPS, also known as sexual seed, is taken from the tomato-like berry of the potato plant. The tiny seeds are much less likely to carry diseases than conventional tuber seed. But one of the greatest virtues of TPS is that it is much more transportable than tubers - making it especially useful for getting potato production back on its feet after natural disasters or other emergencies. Because TPS results from crosses between two plants - or parents - rather than the sprouting of a plant from a single tuber, it allows for increased genetic variability within a crop. This variability may provide some defense against insects and diseases. TPS has become popular in parts of Latin America, India and Southeast Asia, and is likely to spread to other areas of the potato-growing world.

Not all potato research is aimed at fortifying the plant or helping farmers to boost their harvests and cut losses. Much work is being done in such areas as storage, transport, processing and marketing, as well as government policy (on issues ranging from pricing to trade), which can have a greater impact on production than genetics or management.

THE JOURNEY CONTINUES

Since the 1970s, I have watched with personal and professional interest as the potato has found its niche in such countries as Bangladesh, Ethiopia, Indonesia and Uganda. Yet this trend is not really new. The potato has been a central player in the globalization of food, which began during the age of exploration in the fifteenth and sixteenth centuries. As mass communications and transportation accelerate that process, the potato's reach becomes even more universal.

Globalization carries many risks - from the movement of pests and diseases across borders to the loss of local knowledge and traditions - that must be acknowledged and countered. But globalization can also give ordinary people access to a range of choices they never had before. This diversifying tendency is arguably the most important driving force behind the potato's continued spread into new territory, and is proving to be a boon not just for consumers, but for low-income farmers as well.

In highland areas of southern China and Vietnam, the potato is emerging as an off-season crop planted in rotation with rice and maize. Because potatoes are viewed as vegetables there (as they are in most tropical areas), they bring relatively high prices at the market. In the Philippines and parts of Indonesia, a nascent boom in potato production is largely aimed at satisfying the demands of exploding domestic and regional snack food industries. Similar trends are under way in the lowlands of Bangladesh and eastern India, where the potato's importance as a winter cash crop has been rising dramatically in recent years.

In northern China, where wheat has long been the most important staple, potatoes have become increasingly valued as a supplementary crop. They are grown in the summer and stored in warehouses, to be used to meet critical food needs. Yet potatoes are also important moneymakers for farmers who sell their surplus to urban food markets, and supply industry with the raw materials for fries and chips.

The potato is also becoming more important in sub-Saharan Africa, where rural populations are typically dependent on a small number of seasonal staples and where very few potatoes have traditionally been grown. Although they are unlikely to displace mainstays such as manioc or sweet potatoes in most of the continent, potatoes are already proving to be a welcome new source of dietary diversity. This is no small consideration: the potato is rich in protein, calcium and vitamin C, and has an especially good amino acid balance. With its high yields, it is an excellent producer of nutrition per hectare.

The spread of potatoes does not mean that traditional foodstuffs will fall by the wayside. Rather, the buffet will become larger and more varied. Even in the few developing countries where the potato is a true staple, diversity, not predominance, will be the order of the day. In the Andean countries, for example, where potatoes rank at or near the top among all food crops, the trend toward more varied diets means that the relative importance of fresh (i.e., baked or boiled) potatoes should dip slightly. But as populations grow, cities get larger and industrial and market infrastructure gets more sophisticated, processed potatoes will become a much bigger part of the picture. In these countries, as almost everywhere, overall demand will continue to grow. So should the incomes of potato farmers.

My hard-working colleagues at the International Potato Center can take some of the credit for the potato's proliferation - having provided, since the early 1970s, seed, technology and training specifically designed for developing-country conditions. But I like to think that we are part of a much larger process. We are, quite simply, helping the world to get what it wants.