About the Potato Atlas Archives...
The first World Potato Atlas was developed at the International Potato Center (Centro Internacional de la Papa, or CIP) in the 1980s and maintained for several years -- primarily by Robert Rhoades, Robert Hijmans, and Luisa Huaccho -- to provide country-specific information about potato production, constraints, and uses. A newer version of the atlas, providing updated and more detailed information of a limited selection of countries, was initiated in 2006.
The "atlas archives" included here are based on chapters of the original effort which so far have not been substantially updated. Although some of this information is clearly obsolete, some remains relevant, at least for historical background.
HISTORY AND OVERVIEW
Potatoes were introduced to Rwanda around 1900 by German soldiers and later by Belgian missionaries. The most likely places of earliest cultivation were in the gardens of the missions near Gitarama and Butare (Durr, 1983). After the First World War, the area presently comprising the independent countries of Rwanda and Burundi (Ruanda-Urundi) was transferred from a German to a Belgian colony. Rwanda and Burundi gained independence in 1962.
Potatoes grow well in several areas of Rwanda, and despite some initial reluctance due to local food taboos, local farmers eventually adopted the new crop (Poats, 1981). Since national independence, potatoes have played an increasingly important role in the Rwandan economy and the diet of the Rwandan people. Since independence potato area is estimated to have increased at an average annual rate of three to four percent with production increasing at an even greater rate, although with substantial fluctuation (Durr, 1983).
In 1962, the Rwandan Institute for Agricultural Sciences (ISAR), operating under the auspices of the Ministry of Agriculture and Livestock, assumed responsibility for agricultural research and development. In 1979, the National Program for Potato Improvement (PNAP) was established within ISAR in cooperation with the International Potato Center (CIP). The program operates a four-hectare research station at Ruhengeri and a 45-hectare seed farm at Kinigi. The program's mandate includes selection and multiplication of improved varieties for Rwandan conditions, production and distribution of improved seed, development and transfer of techniques to increase potato yields and reduce storage losses, and enhancement of research and extension capabilities through training (Monares, 1984, Haverkort and Bicamumpaka, nd).
GEOGRAPHY AND PRODUCTION ZONES
Some potatoes are grown in each of Rwanda's ten prefectures. However, five of these, Ruhengeri, Gisenyi, Byumba, Gikingoro, and Kibuye account for over 90 percent of the total production (Durr, 1983). The number of potato-growing households in these prefectures exceeds 120,000 (PNAP, 1980). Potatoes are primarily grown above elevations of 1,800 meters above sea level (masl) in the western part of the country.
Three major zones can be distinguished by their geological and pedological characteristics:
- The topography of Ruhengeri and Gisenyi prefectures are dominated by a chain of seven volcanoes. Soils are deep, well drained, and generally rich in nutrients. The communes of Kinigi, Mukingo, and Nkuli in Ruhengeri prefecture and Mutura in Gisenyi are probably the most important potato production areas in Rwanda, with 25-35 percent of cultivated land utilized for this crop. Similarly intense cultivation of potatoes in Gisenyi prefecture occurs in the communes of Karago, Gasehe, and Ramba (Durr, 1983; Scott, 1988; Goeteyn, 1977).
- South of the volcanic zone the prefectures of Kibuye and Gikongoro stretch along the Nile-Congo Divide. Soils here have been under intense cultivation for many years. Although severe leaching and erosion have left these soils acidic and generally depleted of nutrients, these remain important agricultural areas, where potatoes are a major crop. Potato production is especially concentrated in the Rutsiro commune, Kibuye prefecture, and Kivu, Musebeya, and Nshili in Gikongoro (Durr, 1983; Scott, 1988; Goeteyn, 1977).
- East of the volcanic zone lie the Buberuka Highlands, characterized by soils which are generally less leached and more fertile than those of the Nile-Congo Divide. The main potato areas are the communes Cyumba and Kivuye in Byumba prefecture (Durr, 1983; Scott, 1985; Goeteyn, 1977).
In most potato growing areas, average annual precipitation ranges from 1,200 millimeters (mm) to over 1,600 mm. In general rainfall is bimodal with a minor peak occurring in October and a major peak in March to April. The single dry season occurs from May through September and is more pronounced in the Buberuka Highlands than in the other major growing areas (Durr, 1983; Scott, 1983; Goeteyn, 1977).
High elevations and low latitudes combine to form an isothermal temperature regime with an average annual temperature of about 16º C. Diurnal variation in temperature is considerable, often 10º C or more, compared with seasonal variations of less than 2º C between the mean temperature of the coldest month, typically October or November, and the hottest, typically February (PNAP, 1983; Durr, 1983).
PRODUCTION SYSTEMS AND CONSTRAINTS
The Agricultural Calendar
In most areas at least two major crops are planted each year. In the volcanic zone and along the Nile-Congo Divide the main crop is planted around the onset of the dry season - May to July in Ruhengeri and Gisenyi, April to June in Gikongoro and Kibuye. Harvest takes place three or four months later. A second crop is planted in November/December. This is harvested from February to April (Scott, 1988; Durr, 1983; PNAP, 1983) both report the November planting in Kibuye prefecture being harvested as early as December, though this seems like an extremely short season.
Along the Nile-Congo Divide, and especially in the volcanic zones, some farmers grow a slightly later crop in marshy valleys, planting in July and harvesting in October. Another minor crop can be grown from November to March where local conditions are favorable (Scott, 1985; Durr, 1983).
In the Buberuka Highlands of Byumba prefecture the seasonal pattern is similar, though somewhat earlier. The main crop is planted in March and harvested in July. A second planting occurs in October, to be harvested in January/February (Scott, 1988; Durr, 1983).
Although some commercial producers of potatoes in Rwanda cultivate up to ten hectares of the crop, the most important sector of potato production consists of small, traditional family farms growing less than 1.5 ha. of potatoes each year (Scott, 1985). An important feature of Rwandese agriculture is that the total area of all crops is intercropped, including the potato. Varieties are often selected for their intercropping ability (Haugerud, 1985).
Use of purchased inputs such as machinery, fertilizers, pesticides, etc. is very limited. All land preparation is done by hand. Along the Nile-Congo Divide and in Byumba, potatoes are planted on relatively flat land. In the volcanic areas of Giseyi and Ruhengeri prefectures large ridges or "buts" are prepared one meter or more in width and 25-50 centimeters high to permit sufficient drainage in areas of high rainfall (Durr, 1984).
PNAP (1983) suggests 2 tons per hectare (t/ha.) as an appropriate seed rate. However, 1-1.5 t/ha. appears to be typical for farmers. Potatoes are planted with an irregular spacing of 20-40 cm. between plants. Some ridging may be performed after planting, followed by two weedings. Typical yields range from less than 5 t/ha. in Gitarama to over 7 t/ha. in Gienyi and Ruhengeri. When improved seed and other inputs are applied yields can be substantially higher. Under research conditions yields of over 30 t/ha. are readily attainable (Durr, 1983; PNAP, 1983).
The most serious disease affect potatoes in the major production zones of Rwanda is late blight (Phytophthora infestans). This is a particularly serious problem during the rainy season, prompting farmers to delay planting until after the peak rainfall, a practice that carries some risk of drought.
A second serious disease is bacterial wilt (Pseudomonas solanacearum). Erwinia chrysanthemum causes severe local losses of some varieties (Durr, 1983; Haverkort and Bicamumpaka, 1983; Scott, 1988).
VARIETIES AND SEED SYSTEMS
A large number of varieties have been introduced into Rwanda. Two of the most widely grown local varieties are Mbufumbira and Murrubara which are valued for their culinary quality (Durr, 1980). Rwandese farmers typically grown from three to eight different varieties simultaneously, as a risk aversion strategy. In part this takes advantage of the capacity of different varieties to withstand various environmental stresses, such as drought, frost, disease, etc. Similarly this strategy permits utilization of the different varieties according to their economic properties. Haugerud (1985, cited in Scott 1988) found that varieties with desirable culinary qualities were reserved for home consumption while others, with high water content, were cultivated specifically for sale.
PNAP's seed production and distribution goal is to provide most farmers with improved planting material every five years. Given the generally slow seed degeneration rates under Rwandan conditions, this greatly increases the productivity of seed potatoes set aside from one harvest for planting in the subsequent season. Since 1983 the program has distributed 200-300 tons annually of seed to various multiplication projects which in turn distribute seed to farmers (PNAP, 1983; Monares, 1984; Rutayisire, nd).
Farmers generally replant seed from their own fields for three to ten years before virus infections seriously reduce yields. Numerous varieties are grown including some, such as Gashara and Magayne, which have been locally reproduced for 30 years or more since introduction by the Belgians. In the 1970 ISAR introduced several varieties including: Sangema and Montsama, from Mexico in 1972; Bufimbura, from Uganda in 1976; and Condea, from Germany in 1970. In 1982, PNAP released Gahinga, Gasore, Kinigi, and Kseko followed in 1985 by Cruza and Pretero. Sangema is especially popular for its resistance to late blight and floury taste. Gasore is appreciated for its short vegetative cycle, and all the PNAP varieties are know for their high yields (Monares, 1984; Scott, 1988).
CONSUMPTION, STORAGE, AND MARKETING
FAO (1986) estimates per capita consumption of potatoes in Rwanda at 35 kilograms for 1984. Consumption among producers and residents of the main production areas, particularly Ruhengeri and Gisenyi is much higher. Estimates of per capita consumption among producers in Giuye commune, Gisenyi, reached 429 kilograms in 1980, while even non-producers in Kigombe commune, Ruhengeri consumed an estimated 174 kilograms on average. Generally potatoes are consumed by producers, non-producers living in important production zones, and upper income groups living in non- producing, primarily urban areas (Scott, 1988; Durr, 1983).
In rural areas consumers prefer potatoes with a floury taste that remain firm when cooked. The dominant method of preparation is boiling, and watery potatoes, which break apart easily when boiled are poorly regarded. Frying is rare to absent, apparently due to the short supply and high cost of oil. In urban areas there is a distinct preference for large tubers. Neither skin color nor shape are especially important to most consumers (Scott, 1988; Poats, 1982).
On farms both seed and ware potatoes are stored together without curing in bulk, on floors, in stone jars, and in big bamboo baskets. Losses due to rot may reach 20 percent during three months of storage. In recent years some limited adoption of diffuse light storage (DLS) for seed has taken place. The chief obstacles to its adoption by Rwandan farmers include cultural factors such as the visibility of wealth as expressed in the stored crop and its accessibility to thieves, as well as agronomic factors such as the need for fairly rapid sprout development when successive seasons follow closely upon one another (Haverkort, nd; Rutasire, nd).
Most estimates of the proportion of Rwandan potato production that is marketed range between 35 percent and 50 percent. Most farmers reserve a portion of the crop for home consumption, keep about 20 percent for seed and sell the rest. A few potato farms are exclusively market oriented operations (Scott, 1988; Durr, 1983).
An estimated 2,000 tons/year are exported. Of this around 1,500 tons are shipped by long distance truckers to Burundi and the remainder is sold in the Democratic Republic of Congo (formerly Zaire) by small scale local traders. No potatoes are imported (Scott, 1988). About 75 percent of marketed potatoes are traded through local, rural marketing channels. These include informal exchange among relatives and neighbors and sale to local merchants or itinerant rural traders. Local trading of potatoes appears particularly important in the volcanic zone where consumption by non- producers reportedly exceeds consumption by growers in other areas (Scott, 1988).
Rural to urban marketing of potatoes also appears dominated by the volcanic region, with major collection points at Gisenyi and Ruhengeri. Potatoes collected there are shipped to urban markets in Kigali, Butare, and Gitamara. Some trade also occurs from Byumba to Kigali. Trucker/traders buy potatoes from rural traders or in prefectural markets and sell them to urban wholesalers or directly to urban or suburban retailers. In addition to private traders consumer cooperatives buy and distribute potatoes and producers cooperative transport and market them (Scott, 1988). Some potatoes are also shipped from Kigali to other urban areas. Minor amounts of potatoes are marketed as well in non-producing rural areas, brought in directly from the northern production or by traders based in the capital (Scott, 1988).
Bicabumpaka, M. 1982. Potato Research and Transfer of Technology in Rwanda. Paper presented to the Workshop on Potato Research and Transfer of Technology in Tropical Africa. Addis Ababa, 22 August-1 September, 1982.
Durr, G. 1983. Potato Production and Utilization in Rwanda. International Potato Center. Lima, Peru.
Goeteyn, R. 1977. La Pomme de Terre au Rwanda. In: Cours International de la Pomme de Terre. Saida, Tunisia. April 1977. International Potato Center.
Haugerud, A. 1985. Farmers Use of Potato Cultivars in Eastern Africa. Presentation at 1985 Annual Review Meetings. CIP. Lima, Peru
Haverkort, A. Nd. Adoption of Potato Seed Storage in Central Africa. International Potato Center.
Monares, A. 1984. Building an Effective Potato Country Program: The Case of Rwanda. International Potato Center.
Poats, S. 1981. La Pomme de Terre au Rwanda: Résultats Préliminaires d'une Enquête de Consommation. Bulletin Agricole du Rwanda. 14, 82-91.
Poats, S. 1982. Beyond the Farmer: Potato Consumption in the Tropics. In: Hooker, W.K., editor. Research for the Potato in the Year 2000, Proceedings of the International Congress. CIP. Tenth Anniversary. Lima, Peru. pp. 10-17.
Programme National pour l'Amélioration de la Pomme de Terre (PNAP). 1980. Rapport Annuel. Ruhengeri, Rwanda. 80pp.
Programme National pour l'Amélioration de la Pomme de Terre (PNAP). 1983. Rapport Annuel. Institut des Sciences Agronomiques du Rwanda (ISAR).
Rutasire, C. Nd. The Present Situation of Potato Production and Storage Technology for Seed and Ware in Rwanda. Programme National pour l'Amelioration de la Pomme de Terre.
Scott, G. 1988. Potatoes in Central Africa: A Study of Burundi, Rwanda, and Zaire. International Potato Center. Lima, Peru.