Potato and sweetpotato as sources of food

With its high nutritional value and great yield potential, potato is the world’s fourth most important food crop, after wheat, rice, and maize. Potato provides roughly half of the world’s annual output of all roots and tubers, making it the largest non-cereal crop. About 35% of world production is in developing countries—about 100 million tons—where potato is a staple in the diet of half a billion consumers.

The potato plays an increasingly important role in the daily nutrition of poor subsistence farmers, and is often a main source of cash income. In the potato-producing areas of Peru, Ecuador, Bolivia, Rwanda, Nepal, Tibet, and China, per capita consumption of potato often exceeds 200 kg/year. Potato is a particularly important food source and cash crop in mountainous areas, where some of the world’s poorest people live.

Sweetpotato ranks as the seventh most important crop in the world, with an annual production of over 125 million tons. Nearly 95 percent of the world’s sweetpotato production is in developing countries. In Asia and Africa, sweetpotato is historically a subsistence crop, especially in areas where people’s food security is at high risk. It can grow and produce edible storage roots in marginal environments, where other food crops fail, making it a valuable crop for resource-constrained farmers.

In most parts of Central Africa, for example, sweetpotato is a major contributor to household food security, both as a staple food and a seasonally important secondary crop. More intensive production zones are found in East Africa, in the countries surrounding Lake Victoria, including Uganda, Rwanda, Burundi, Congo, and parts of western Tanzania and Kenya. In recent years, as a result of an epidemic of African Cassava Mosaic Virus disease that has reduced cassava yields, sweetpotato has become the main staple and cash crop in many areas throughout Sub-Saharan Africa.

Production constraints

Disease and insect pests are major constraints to potato production. Potatoes are subject to disease-related losses of 21%, the highest figure for all crops. Average yields worldwide approximate 13 t/ha, but the yield potential of existing genotypes could raise this average to 40 t/ha, if pests and diseases could be controlled. Of the world food crops, potato is the largest single recipient of agricultural pesticides. Dependence on these chemicals has increased production costs and exposed the environment, farm worker, and consumers to associated health risks. Pesticides are often handled inappropriately and, in general they are poorly regulated in developing countries. At the same time, lack of access to pesticides reduces potato production. In this way pesticides have forced their way into a pivotal role in the fragile economy of small producers.

With sweetpotato, insect damage results in poor quality of the harvested crop—for consumption, or for use as new planting material. Poor quality also creates problems associated with marketing.

In these respects, the application of biotechnology in potato has made major progress and sweetpotato research holds great promise. These modern techniques can be employed to lessen the dependence on pesticides by incorporating resistance directly into the crops. The results of research in this area can help reduce risks to the environment, avert unnecessary exposure of farm workers and consumers to toxic pesticides, and contribute to increased food security and profitability.

Through its scientific capability, and through its regional programs in Asia, Africa, and Latin America, the International Potato Center is well poised to concentrate efforts to overcome these obstacles to potato and sweetpotato production. Indeed, CIP has the commitment and the global mandate for such work in the international research community.