POTATO: A FRAGILE GIFT FROM THE ANDES

Often characterised as a poor man’s staple, the so-called "humble" potato is actually a kingly food. Producing more calories and high quality protein per square metre than any other major food plant, it can be grown in as little as 60 days. This treasure of the Incan empire is the world’s third most important crop for human consumption. But it comes with a price: it is the world’s most stress-susceptible and chemical-dependent major crop.

Potatoes have traditionally been consumed fresh, and they are sown out of potato tubers rather than from seeds, which means that they are especially prone to disease. Because of this, international potato trade has been severely limited by phytosanitary measures. But in the hands of the fast-food industry, which is increasingly controlling production in the North and now the South, the potato is becoming quite the global traveller. Over the last few decades, developing countries have increased their share of global output from 11% (1961-63) to 37% (1995-1997). Some of this increase is due to some countries (such as Egypt) exporting off-season seed and edible potato to Northern markets. But much of it has arisen from the promotion of potato by the International Potato Center (CIP). CIP has promoted potato in Africa and Asia as a key element for countries’ food security. Production may have increased, but what about food security? Is the industrialised version of the potato really a suitable crop for small and traditional farmers in the South to invest their energy and resources in?

The Andean zone is one of the world’s main centres of plant domestication and diversity and the home of the potato (see box). Mexico is a second centre of diversity. As soon as human populations started farming in the region, they began cultivating diverse species of potatoes (Solanum sp.), while also gathering and eating wild tubers. No other major food crop enjoys as high a genetic diversity within its cultivated species and wild relatives as potato. While for most of the rest of the world the potato crop depends on a single species (Solanum tuberosum), in the Andes at least nine different Solanum species are cultivated. Wild relatives provide a further 226 species.

Potatoes are grown in most of the crop zones in the Andes, and they dominate the upper zones, between 3,000m and 4,000m above sea level. The Aymara people alone developed more than 200 varieties on the Titicaca Plateau at elevations higher than 3,800m. Andean farmers distinguish between two main types of potato. Bitter, frost-resistant haya papa are planted at high altitudes. Mikhuna papa types, without bitter compounds, are planted in mid-altitudes. The Aymara people invented the freeze-dried potato, which they call "chuño," to enable them to store potatoes year-round. To make chuño, potatoes are spread on the ground to freeze overnight. The next day, they are trodden to squeeze out the water. Several days later, the chuño is dried and stored.

The preservation of biodiversity in the Andean agricultural systems arises from the cosmovision of Quechuas and Aymaras, which is based in the nurturing of harmony and the mutual support between the three groups that make up the ayllu: the community of the sallqa (nature), the community of runas or jaques (humans), and the community of wacas, deities (Seedling Vol. 15, No. 2, June 1998). Any on-farm conservation effort which does not respect this cosmovision is likely to be at best, short-lived, and at worst, exploitative.

Europeans first came in contact with the potato in the Magdalena valley in the Colombian Andes in 1537, and its first recorded use in Europe was at the Sangre hospital in Seville in 1573. Potato was introduced in the US in the early 1700’s, probably from Ireland. In Europe, the potato was initially regarded as poisonous or unhealthy, and spread across Europe as an ornamental, through exchanges among botanists. It was not until the Napoleonic wars (1805-1815) that potatoes were accepted as food. The potatoes grown at the time were selections from the original andigena types (Solanum tuberosum subsp. andigena) introduced by the Spaniards, and as such they had a very narrow genetic base.

This shaky foundation caused the first recorded crop failure due to genetic uniformity: the wipe-out in 1845 of virtually all European potatoes by a single infection of late blight, Phytophthora infestans. Inadvertently introduced in the US by a biologist returning from Mexico, the fungus had already ravaged potato crops throughout Eastern Canada and the American Mid-West. In Ireland, the effects of the epidemic were catastrophic. England’s colonial rule and the concentration of land tenure had left the Irish poor relying on the potato almost exclusively for their food security. The devastation of the crop resulted in the deaths of 2.5 million people, while another million had to migrate to North America. Perhaps less recognised was the concomitant spread of potato blight to Asia, Africa and Brazil. It was only after 1860 that P. infestans lost some of its virulence (see Seedling Vol. 12, No.3, Oct. 1995), and it remains today’s most challenging potato disease (see box).

Potato is a particularly vulnerable crop because it reproduces asexually. It is susceptible to more than 300 pests and diseases, and pathogens in the parent tuber are directly transferred to the harvest and spread to the next generation. Potatoes are prone to viral, fungal and bacterial diseases, predation by insects and nematode infestation. Because of the very narrow genetic base introduced by the Spanish, potato breeding programmes keep turning back to Andean potato germplasm to search for resistance genes, and for sources of cytoplasmic male sterility (for the production of potato hybrids), frost resistance and yield enhancers. A 1989 survey in the US revealed that 11 wild species were present in the pedigrees of 124 varieties released to date, but overall diversity remains dangerously low. The most popular variety in the US, Russet Burbank, developed by Luther Burbank in 1875, accounts for 74% of the fall season varieties US main potato producer state of Idaho. Genetic uniformity is just as extreme in some parts of Europe. In Flanders, Belgium, a single variety developed in 1905, Binjte, accounts for 77% of the acreage of the main potato crop.

Yield increases in the most intensive potato growing areas of the US and Europe have been spectacular. According to the UN’s Food and Agriculture Organisation (FAO), average potato yields in 1998 in the US, UK and Germany were close to 40 tonnes per hectare, while those of the Netherlands and Canada were just below 30 tonnes per hectare. As a comparison, average yields in Peru and the Russian Federation are slightly below 10 tonnes per hectare. But these yield increases have come at a price: the intensive use of agrochemicals, genetic erosion, environmental damage and farmers’ loss of autonomy. Farmers’ manoeuvring space has become very tight. As the New York Times reported recently,

"The economics are daunting : a potato farmer in south-central Idaho [US] will spend roughly $1,965 an acre (mainly on chemicals, electricity, water and seed) to grow a crop that, in a good year, will earn him maybe $1,980. That’s how much a french-fry processor will pay for the 20 tons of potatoes a single Idaho acre can yield."

The Green Revolution was the US-promoted export of its agricultural model to developing countries, with three main objectives: avoiding hunger-led spread of Communism by industrialising crop production, integrating developing countries into international markets for US agricultural products, agricultural inputs and technologies, and creating a centrally-controlled system of ex-situ conservation of varieties to support the main staple crops. Since its creation in 1971 in Lima, the International Centre for Potato (CIP) has had the mission to implement this agenda for the potato, sweet potato, and other roots and tubers. CIP has also strongly promoted potato cultivation in developing countries in Asia and Africa.

High external input varieties were developed by Peru in the 1950s, and by Colombia and Chile in the 1970s. By the mid-1980s, only in Bolivia was most commercial production still based on landraces, while in Peru more than one half of the commercially-cultivated varieties were high external input. Modernisation has pushed for a new cultivation pattern where most potato surface is monocropped to improved varieties or commercial native varieties. According to CIP, medium-sized Andean farmers owning 5 to 6 hectares plant 80%-90% of their land to improved varieties, 8% to 9% to commercial native varieties, and an important 1% to a diverse potato plot for home use. While most of farmers never buy new seed potato for their traditional varieties, high exernal input potatoes must be purchased every two or three generations, and are thus are only an option for larger farms and wealthier farmers.

Andean farmers have been stricken by the vicious circle of dependency on ever more expensive chemical inputs, indebtedness, falling prices and environmental degradation that have accompanied the introduction of high external input varieties of other crops. Another impact of "modernisation" has been the expansion of potato cropping out of the mountains. In Peru, commercially certified seed and irrigation have enabled expansion into coastal areas, where production (10% of Peru’s output) is oriented to markets in urban areas. As a result, the potato’s rich diversity is quickly being eroded. According to the 1996 FAO report on The State of the World’s Plant Genetic Resources for Food and Agriculture, in Peru, 35 of the 90 wild potato species that have been described are no longer found in the wild, due mainly to the destruction of their ecological niches.

The impact of the Green Revolution and agricultural liberalisation for potato in the Andean region is well illustrated by Colombia, a country that has strongly supported formal research on potato through credit, the use of new varieties, new inputs, and public research. Colombia is the main potato producer of the Andean Pact countries. Some 90% of Colombian potato growers are small, peasant farmers owning less than 3 hectares, who grow potato for subsistence and commercial purposes and use traditional varieties yielding about 10 tonnes/hectare. They produce 45% of the national total. Medium-size farmers owning 4 to 7 hectares make up 7% of growers and account for 35% of the potato production, with yields close to 15 tonnes/hectare. Finally, 3% of Colombian farmers have plots larger than 10 hectares, and produce 20% of national potato with extensive use of inputs and yields close to 20 tonnes/hectare. However, the penetration of certified seed in Colombia has been low, with only 1% of it being certified by the mid-1980s, with virtually all seed being farm-saved, exchanged or locally purchased.

Colombia has become an exporter of table potatoes and common seed to Ecuador and Venezuela, and intends to get a larger share of the export market in other Andean countries, within the frame of the Andean Pac free trade area. Producers from Peru, Colombia, Ecuador (and perhaps also Argentina) are increasingly competing for market shares in urban areas, where the fast food industry is growing rapidly. These are served with standardised potatoes grown according to the industrial model and a handful of preferred landraces. The market is not negligible: in one year, Peru imported 19,000 tonnes of pre-cooked and frozen potatoes for the fast-food multinationals. This shift in emphasis in potato production from local markets to urban markets controlled by multinational companies is marginalising small-scale farmers hoping to sell some of their crop. This has serious implications for their livelihoods and the diversity they rely upon.

CIP is aware of the bleak prospects both farmers and potato diversity face. But its solutions are also market-oriented. CIP’s three-year long "Native Potato Seed Repatriation" programme supplied farmers in a poor region of the Peruvian Andes with 1,200 virus-free traditional varieties. The objective was to introduce both the farmers and their varieties to modern commercial circuits, by generating speciality markets both in Peru (where good "criollo" varieties may fetch five times the price of an improved variety) and for export. Albeit well-intentioned, this strategy seems a little short-sighted. Firstly, the number of Peruvian consumers able to pay a premium for quality potatoes is pretty limited. Secondly, there are few examples where supplying export markets has really proved to be a viable option for small farmers, or where their communities have really gained much.

CIP’s genebank now holds seed stocks of 1,272 accessions of 140 wild potato species, and about 3,500 accessions of local varieties. Most of these originated in farmers’ fields in Latin America. For many years, CIP has tried to develop closer collaboration among potato genebanks around the world. One result has been the establishment of an Inter-Genebank Potato Database, which contained 11,590 wild potato accessions in 1997. CIP policy is to make these materials freely available to all parties. But the trend towards privatising research means that CIP, like many other International Agricultural Research Centres, is in rather an uncomfortable position (see box).

One of the main objectives of CIP has been to expand the use of potato as a key contributor to food security in developing countries. Fighting late blight, viruses, bacterial wilt and potato tuber moth are current priorities for CIP. Endemic bacterial wilt, caused by Ralstonia solanacearum, causes severe crop losses in tropical, subtropical, and warm temperate regions. Because bacterial wilt cannot be stopped through the use of agrochemicals, CIP’s approach focuses on developing early detection kits, screening its genebank materials for resistance, and promoting integrated control approaches to contain its expansion. The main insect pest of potato in the tropics is the potato tuber moth. The moth attacks potatoes both in the fields and in storage, both in the lowlands and the highlands. The current CIP approach is the development of transgenic potato varieties containing a gene from Bacillus thuringiensis, developed and patented by Plant Genetic Systems (now owned by Aventis) and the use of a protease inhibitor gene from Axis Genetics.

Another priority of CIP has been to overcome the strong limitation in access to healthy potato seed in developing countries, due to the lack of adequate storage facilities, difficulties in transportation and the difficulty to keep potato seeds virus-free. CIP has rescued a technology that the Aymaras and Quechuas already put in practice in order to renovate their potato stock: True Potato Seed (TPS). The benefits to farmers however, are marginal at best (see box). While the focus of CIP’s research programme may be questioned, it has certainly been successful in shifting production back toward the South. India is currently the world’s fourth potato producer. Although potato was introduced in India from Europe in the 17th Century, its production has skyrocketed since it has been integrated into input-intensive and irrigated potato-wheat-rice or potato-rice rotating systems in the Indo-Gangetic Plain. As the rest of the components of Green Revolution systems, potatoes are grown primarily for cash. But Indian potato farmers do not always see their investments rewarded: deficient cold storage capacity and the lack of marketing infrastructure often result in depressed prices at harvesting, and in fact potato growing is seen as a high-risk and capital-intensive activity.

Potato is now seen as the third most important food crop in India after rice and wheat. Because of potato growing in India is high-risk and capital-intensive. Established in 1949, the Indian Central Potato Research Institute (CPRI) now has 9 regional research stations and 22 research centres. It’s germplasm collection comprises 2,500 accessions, and it has introduced 34 varieties into the country. India is engaged in at least two projects for genetic engineering the potato. Although the processing industry in India is quite limited at the moment, the situation is likely to change in the coming years. India’s progress in potato production has certainly benefited from CIP germplasm accessions, breeding lines, TPS, and support, but questions still remain around what those benefits really are. Is the chemical-greedy potato really a blessing or a plague if all the environmental and human costs are factored in?

Potato breeding has traditionally been a long process: it can take up to 25 years to develop a new variety. The main reason for this is that the cosmopolitan species, Solanum tuberosum, is tetraploid, which means it has four complete sets of chromosomes. This makes for complicated breeding programmes. If genes from wild potatoes are desired, the process is even more complex since wild relatives may have two, four or five sets of chromosomes. Genetic engineering is therefore particularly appealing to potato breeders. They see endless possibilities of using genetic engineering not only as a way to make potato cultivation less dependent on agrochemicals, but also to turn the potato into a bioreactor for industry. Commercial outfits are also drawn to genetic engineering because of the potential to patent and reap royalties from their new varieties.

Some developing countries have developed their own transgenic potatoes. The Central Potato Research Institute of Simla, India, has field-tested its own Bt toxin gene, while the Jawaharlal Nerhu University in New Delhi has tested a potato expressing a gene for seed protein containing lysine obtained from seeds of Amaranthus plants (Ama-1 gene). Brazil’s EMBRAPA has field-tested Potato Virus Y-resistant potatoes, and South Africa’s ARC Vegetable and Ornamental Plant Institute has field tested its own potato leaf roll virus resistance technology.

Potato has also been one of the focuses of the USAID-financed Agricultural Biotechnology Support Project of Michigan State University, which has transferred a Gast-Seed Company-owned Bt gene to Egypt’s Agricultural Genetic Engineering Research Institute for potato tuber moth control. Egypt is an important potato exporter for Europe, and a good market for the Dutch seed companies. CIP has developed a potato tuber moth-resistant transgenic potato using Plant Genetics System’s patented Bacillus thuringiensis gene and field tested it in Peru.

Farmers have started to get wind of foreign interests starting to dump genetically-modified potatoes on them and are starting to resist such introductions (see box). Monsanto has also used genetically-engineered potatoes in "small farmer-oriented" technology transfer programmes. An example is the ISAAA-brokered collaboration between the Mexican public research centre CINVESTAV in order to develop transgenic virus-resistant varieties for small farmers. Mexico’s Biotechnology and Society Research Group reports, however, that small farmers were not consulted. It also suggests that the real problem for small-scale farmers is weakening of the public potato seed distribution system rather than the absence of virus- resistant varieties. While Monsanto is quick to point out that it stands nothing to gain in terms of market share, it hasn’t gone unrewarded. One big benefit was that it got to advise the government in drawing up industry-friendly biosafety regulations.

The potato has been an important staple for communities in Andean countries for many centuries. It then became established as a staple in many countries in the North, where it is largely grown according to the industrial model. This model is now being promoted in the South, and the fate of the potato is being grabbed from farmers’ hands and placed under corporate control The trend will most probably be strengthened in the future, as agricultural markets open and storage options improve. The lowering of phytosanitary barriers to potato seed markets and the increasing trade in processed and pre-processed potatoes will probably increase global potato exchange. Northern fast-food companies are quickly expanding in the South and demand is increasing globally.

Reliance on industrially-cropped potato is a risky business. First, late blight still has tremendous potential to devastate the planet’s harvest. Second, in spite of the efforts by CIP to introduce Integral Pesticide Management practices, most potato growing still requires the heavy use of pesticides with damaging effects on farmers’ health and on the environment. In addition, there are serious concerns about who will benefit from the potato’s expansion. One serious consequence is that small subsistence producers in the Andes who maintain potato’s genetic heritage are getting pushed out of the production loop. In addition, the expanded demand for potato in the South is a consequence of increasing urbanisation and the adoption of Northern life styles and dietary shifts. The South’s new potato eaters are the well-off rather than the humble. Through its aggressive expansion, the fast food sector may end reaping the largest share of the results of CIP’s efforts.

Most current research on the potato is directed towards growing a product to suit the needs of the fast food industry. Those aimed at helping the potato to thrive in new environments in the South are often appropriately motivated, but perhaps misdirected. CIP has a long history of making germplasm available to farmers and institutions in the South, with the aim of producing potatoes tailored to the needs of local farmers. But its strategy for dealing with potato infestations should be questioned. Part of the reason that the potato is so afflicted by disease is that it does not do well in monoculture production. Many of the diseases that CIP is trying to combat are complications of the industrial model of agriculture. The potato moth, for instance, becomes a much more serious problem if the fallow period is removed. Many diseases could be largely combated by promoting diversified farming systems and diversified potato varieties.

The huge investments that CIP and other interested parties are taking in genetic engineering should also be treated with caution. Genetic engineering necessarily undermines biodiversity, which is the long-term key to keeping on top of crop diseases. Public sector institutions cannot enter into genetic engineering research without the support of the private sector. When corporations control the research agenda, they are the ones who will benefit from the fruits of research, not farmers and not consumers.

Main sources:

* B Ahloowalia (2000) "Global conference on potato." New Delhi, India 6-11 December 1999, AgBiotechNet 2000, Vol. 2 May, ABN 049

* Ma rc Ghislain et al (1997) "The Application of Biotechnology to Potato", Agricultural Biotechnology in International Development, CAB International 1998.

* D Horton (1987) Potatoes: Production, Marketing and Programs for Developing Countries, Westview Press, Boulder (USA), 1987.

* Z Huamán et al (1997). The Potato. Chapter 2, pp 21-28 in Biodiversity in Trust: Conservation and Use of Plant Genetic Resources in CGIAR Centres (D Fuccillo et al, editors). Cambridge University Press, Cambridge, UK.

* G Scott et al (2000) Roots and Tubers for the 21st Century Trends, Projections and Policy Options, IFPRI and CIP, Peru, May 2000. Downloadable from http://www.cgiar.org/ifpri/pubs/catalog.htm#dp.