INTERNATIONAL POTATO CENTER: WORLD SWEETPOTATO ATLAS
ANGOLA
HISTORY AND OVERVIEW
The sweetpotato, Ipomoea batatas, originated in the American tropics roughly defined by the Caribbean and adjacent areas of South and Central America. Columbus brought sweetpotato with him on his return to Spain from his first voyage to the Americas in 1492, eighty years before the potato reached Europe (Purseglove 1968, p. 81). By the 1520s, Portuguese mariners were carrying sweetpotato to ports and territories throughout Africa and Asia, a diffusion subsequently continued by other Europeans (Huntington). The record for the following several decades is unclear since the term "potato" was derived from "batata," the Carib term for sweetpotato. Documented references to "potato" could therefore be referring to either crop, both of which have become significant to Angola.
The current role of sweetpotato, and more generally the status of agriculture in Angola, can only be understood in light of tremendous disruptions over the past several decades. Angola gained its independence from Portugal in 1975 following several years of armed conflict, led primarily by the People's Movement for the Liberation of Angola (MPLA) based primarily in the north, and the National Union for the Total Independence of Angola (UNITA) in the south. Upon independence, differences between the two factions resulted in intermittent civil war which lasted for over 25 years. Only since April 2002 has Angola experienced its first peace and stability, improving the conditions under which agricultural developmen can occur.
Sweetpotato has become well established in Angola, as in many relatively humid areas of Africa, due to its high yield relative to both land and labor, its capacity to grow in relatively poor soils, and its high content of carbohydrates and vitamins, especially vitamin A. Agricultural data in general are very tentative, but the United Nations Food and Agriculture Organization (FAO) ranks sweetpotato production in Angola third, behind cassava (by far the main crop by weight) and slightly behind maize (FAOSTAT). Sweetpotato has frequently been cited as a crop which has sustained people in Angola through failures of other crops and especially through famines caused primarily by recurrent war and upheaval (FAO/WFP).
Hundreds of thousands of Angolans displaced by civil conflict remain vulnerable to food shortages as they return home lacking inputs to reestablish agricultural production in areas where little is left of the physical infrastructure. In 2004, for example, inadequate farm inputs and excessive rainfall the previous December seriously affected crops, especially maize, across areas of Huambo, in the central region (FEWSNET). Several months later, food stocks remained critically low, but the recovery of the sweetpotato and bean crops had helped the area maintain food security between May and August (IRIN).
Given the importance of sweetpotato as a "hungry season" crop, it is possibly being cultivated in Angola to a far greater extent than can be estimated under the conditions of the country. FAO and the World Food Program (WFP) estimated in 2003 that approximately 438,500 tons of sweetpotato are grown on 116,600 hectares of land (FAO/WFP). However, in Mozambique, a country which likewise experienced decades of civil war following independence from Portugal in 1975 (but has known a longer relative peace), a survey undertaken in 2004 estimated the area of sweetpotato cultivation at over ten times the FAO estimate. (Please refer to the Mozambique chapter.) Sweetpotato yields in Angola, estimated by FAO and WFP at 3.76 tons per hectare, are low even relative to the region, suggesting that the crop has high potential for improvement.
Sweetpotato is currently being developed as a means to address one of the most serious health and nutrition problems of sub-Saharan Africa, Vitamin A deficiency. Lack of Vitamin A can weaken the immune system, leaving an individual more susceptible to deadly diseases such as measles, malaria, and diarrhea. Vitamin A deficiency is also a leading cause of visual impairment and a major risk factor for pregnant and lactating women.
The International Potato Center (CIP) is a major partner of Vitamin A for Africa (VITAA), a project intended to develop and distribute throughout several countries in sub-Saharan Africa a new series of sweetpotato cultivars which are rich in betacarotenes, used by the body to synthesize Vitamin A. The VITAA project is an example of biofortification, intended to develop crop varieties with increased mineral and vitamin content to enhance nutritional standards. Angola, given its current and potential production of sweetpotato and its nutritional needs, could likewise benefit from this initiative.
For more information, please see:
GEOGRAPHY AND PRODUCTION ZONES
Physical Geography and Climate
Angola can be characterized by three principal natural regions (US LOC: Geography):
- The coastal lowland, characterized by low plains and terraces;
- Hills and mountains, rising inland from the coast into a great escarpment;
- An area of high plains, called the high plateau (planalto), which extends eastward from the escarpment.
The coastal lowland rises from the sea in a series of low terraces, varying in width from about 25 kilometers near Benguela to more than 150 kilometers in the Cuanza River Valley just south of Angola's capital, Luanda. The Atlantic's cold northward current reduces precipitation along the coast, making the region relatively arid, at its southern extent forming the northern extension of the Namib Desert. Predominant coastal land cover ranges from sand dunes in the south to dry scrub along the central coast to thick brush in the north.
Hills and mountains are characterized by gradually rising elevations in the north, to an average of 500 meters above sea level (masl), with crests as high as 1,800 masl. Hills of the south generally rise sharply from the coastal plains to form a high escarpment reaching 2,400 masl at its highest point.
- Several maps of more specific classifications — for example by soil types, agro-ecological zones, and land use — are available from the European Digital Archive of Soil Maps, Angola
. Most images are digitized from paper maps, of variable clarity.
Angola experiences distinct rain and dry seasons. In the north, the rain season can last as long as seven months, usually from September to April, but usually diminishing somewhat in January or February. In the south, the rain season begins later, usually in October or November, and lasts until February or March. In general, precipitation is higher in the north, but at any latitude it is generally greater in the interior than along the coast and increases with altitude (US LOC: Angola Geography).
Temperatures, decreasing with distance from the equator and with altitude, are generally higher in areas closer to the Atlantic coast. At Soyo, at the mouth of the Congo River, the average annual temperature is about 26°C, but it is under 16°C at Huambo on the temperate central plateau. The coolest months are July and August, corresponding to the dry season, when frost sometimes occurs at higher altitudes (ibid.).
Regional Distribution of Sweetpotato Production
The sweetpotato crop is widely grown in Angola, but there is a greater concentration to the north and central regions of the country away from the coast, corresponding to areas of higher precipitation, but below the colder high altitude plains. Very little production is reported from the more arid southern region.
- Production data by district from 2003 for several crops, including sweetpotato and potato, are reported by the UN Food and Agriculture Organization and the World Food Programme, FAO and WFP.
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Sweetpotato Distribution in Angola
Please click on this thumbnail image to view the map.
This map displays primary areas of sweetpotato cultivation, based on area and yield data by province (18 total) provided by the Food and Agriculture Organization (FAO) and the World Food Programme (WFP) "Special Report, Crop and Food Supply Assessment Mission to Angola, 25 July 2003." The report cites the Angola Food Security Department, Ministry of Agriculture as a source of data, in addition to mission estimates.
Total area of cultivation represented on this map is 144,000 hectares, the estimate reported by FAO for 2003, but an increase from the approximately 117,000 hectares reported in the original report. FAO estimates of sweetpotato cultivation have continued to rise dramatically with each succeeding year. The map nonetheless likely remains roughly accurate as a portrait of regionally relative sweetpotato cultivation and productivity.
Two provinces are not included in the report, Benguela to the central east and Cunene to the south. Although these are, as described in the chapter text, areas of very low productivity for sweetpotato, they are nonetheless shaded as "no data" since other areas of low productivity are included.
PRODUCTION SYSTEMS AND CONSTRAINTS
Agriculture in Angola is almost entirely dependent on rainfall, often a factor of altitude. Predominate crop distributions include (FAO/WFP 2003):
- Cassava, the main crop in the northern region, occupying over three fourths of all area planted. Other crops, including sweetpotato, maize, beans, millet, and groundnuts, are grown in an intercropping system;
- Maize, the main food staple in the central highlands, where the tropical climate is modified by higher altitudes. Potato has also become an important crop at higher altitudes, serving the same vital function as a "hungry season" crop that sweetpotato provides at lower altitudes;
- Millet and sorghum, more important in the drier southern regions;
- Sweetpotato, concentrated in the northern and central regions, generally consistent with higher rainfall and mild temperatures.
Given the lack of available data pertaining to crop production in Angola, little is known of specific cultivation practices or diseases and other constraints of sweetpotato production. Cultivation is almost entirely by smallholders (one reason why production data are difficult to obtain). Fertilizers and other inputs, to the extent that they are available in Angola, would be used for higher value commercial crops such as coffee and cotton, not sweetpotato.
A widespread and damaging pest constraint to sweetpotato cultivation in eastern and southern Africa in general, particularly in dry areas or in dry years, is the sweetpotato weevil (Cylas spp.) (CIP Program report 1995-96). In warm moist areas typically characterized by bimodal rainfall, such as much of central and northern Angola, viral diseases and moles are frequently major constraints, but more specific data for Angola are not yet available (Zhang).
VARIETIES AND SEED SYSTEMS
Sweetpotatoes grown by farmers in Angola are almost certain to be derived from varieties which have been present in the area for many years. CIP has worked with local partners in several other countries in the region to improve the access of farmers to promising varieties of sweetpotato, through programs designed to:
- Collect, characterize, and conserve local varieties;
- Introduce promising varieties as appropriate from other areas;
- Distribute the most promising varieties;
- Maintain systematic screening of varieties using participatory methods based on genotype by environmental effects (Zhang).
Although agricultural research in general has been another casualty of the many years of disruption due to war, a few varieties have been released by CIP to Angola, from 1998 to 2000 including (official and CIP designations) (Zhang):
- L312 (CIP 440243)
- LO323 (CIP 440185)
- Zapallo (CIP 420027)
- Jonathan (CIP 420014)
CONSUMPTION, STORAGE, AND MARKETING
If production estimates are reasonably accurate, then the 438,508 tons of sweetpotato produced in Angola in 2003 would, for a population estimated at 13,625,000 average out to slightly above 32 kilograms per capita annual consumption. This is high by world standards, though much less than a few other countries of Central Africa, such as Uganda and Equatorial Guinea, where annual per capita consumption is around 100 kilograms (FAOSTAT).
Data pertaining to storage and marketing are not yet available.
Contact information for the Angola Ministry of Agriculture and Rural Development is available via the Angola Embassy to Austria, Croatia, and Slovenia.
Angola is a member of the Southern Africa Root Crops Research Network (SARRNET). Summaries of current research, including varietal development and biological controls, is available via SARRNET.
The Famine Early Warning System website, FEWSNET, posts regular reports pertaining to food security in several countries, including Angola (in English).
CONTRIBUTORS
Kelly Theisen is the principal contributor to the initial (2006) Angola chapter of the Sweetpotato Atlas.
REFERENCES
BBC Country Profiles: Angola
CIP Program Report 1995-96. Overview of Work in Sub-Saharan Africa.
FAOSTAT. (Agriculture/ Agricultural Production/ Crops Primary) and (All Databases/ Population/ Annual Time Series).
FAO/WFP. Food and Agriculture Organization, World Food Program. Special Report. FAO/WFP Crop and Food Supply Assessment Mission to Angola. 25 July, 2003.
FEWSNET (Famine Early Warning Systems Network) April, 2004. Crop Losses Threaten 300,000 in Huambo.
Huntington Library Plant Trivia Timeline.
IRIN (United Nations Integrated Regional Information Networks). Angola: Thousands Face Food Shortages
Purseglove, [J.W] 1968. Tropical Crops: Dicotyledons. Longman Group Limited. Essex, England.
US LOC (United States Library of Congress) Angola: Geography
Zhang, Dapeng. Progress with the Breeding and Deployment of Orange-Fleshed Sweetpotato for Sub-Saharan Africa. Power Point presentation. CIP. Lima.