Cassava, Africa's Food Security Crop

by Taye Babaleye, IITA


Cassava (Manihot esculenta ) originated in the Americas. It is a shrub with an average height of one metre, and has a palmate leaf formation. Cassava belongs to the family of rubber plants with a white latex flowing out of its wounded stem and leaf stalk. The stem is the planting material from which grows the roots and shoots. Cassava produces bulky storage roots with a heavy concentration of carbohydrates, about 80 percent. The shoots grow into leaves that constitute a good vegetable rich in proteins, vitamins and minerals. New knowledge of the biochemistry of the crop has proved that the proteins embedded in the leaves are equal in quality to the protein in egg. Cassava leaves and roots, if properly processed, can therefore provide a balanced diet protecting millions of African children against malnutrition.

During the Nigerian civil war, Flora Nwapa, a Nigerian novelist and poet wrote in praise of cassava:

We thank the almighty God
For giving us cassava
We hail thee cassava
The great cassava

You grow in poor soils
You grow in rich soils
You grow in gardens
You grow in farms

You are easy to grow
Children can plant you
Women can plant you
Everybody can plant you

We must sing for you
Great cassava, we must sing
We must not forget
Thee, the great one

Because of its massive leaf production which drops to form organic matter thus recycling soil nutrients, cassava requires little or no fertilization and yet will maintain a steady production trend over a fairly long period of time in a continuous farming system. With its ability to suppress weeds particularly the improved varieties which develop many branches early enough to form a canopy shading weeds from solar radiation, cassava as a crop is a friend of the scale farmer whose weeding operation is drastically reduced. Whereas other crops such as yam, maize, banana and plantain, cowpea or sorghum and millet are ecoregionally specific, cassava is probably the only crop whose production cuts across all ecological zones. Talking about cassava s adaptability to the tropical African environment, Alfred Dixon, a cassava breeder at the International Institute of Tropical Agriculture (IITA) in Ibadan, Nigeria says "Cassava is to the African peasant farmers what rice is to the Asian farmers, or what wheat and potato are to the European farmers."; Advances in cassava research and its adoption rate by African farmers. Cassava, the neglected crop of the down-trodden, is fast becoming an elite foodcrop in sub-Saharan Africa, thanks to the research efforts of scientists at IITA and national agricultural research systems in the continent. Two major diseases of cassava-the Bacterial Blight and Leaf Mosaic-have been controlled through genetic breeding and the incorporation of resistance genes into high yielding cassava varieties by IITA. Also, through its ambitious, Africa-wide program of the biological control of the cassava mealybug, IITA has waged a successful war on a devastating pest.

Having freed Africa's most friendly crop from the vagaries of some of the prevailing diseases and pests, IITA now has many improved cassava varieties available that are high-yielding and early maturing. The unattractive six tons-per hectare-varieties which are late maturing have now given way to varieties that yield 20 - 30 tons per hectare in just twelve months.

The Institute has embarked on a campaign strategy to constantly transfer these improved varieties to African research institutions. IITA's new research thrust is pushing cassava yield to more than 40 tons per hectare on the farmers' fields. Dubbed "super cassava", the new varieties will be available to farmers in a few years' time. Equally, IITA-in collaboration with the Centro International de Agricultura Tropical (CIAT) in Colombia-has been pushing improved, drought-tolerant cassava varieties to the drier areras of the Sahel, the Kalahari and the high altitudes of Eastern and Southern Africa.

The adoption has been gradual, first on a farmer to farmer basis in Nigeria and in other countries with strong collaboration with IITA. Later, Nigeria s National Seed Service (NSS) and the National Accelerated Food Production Program (NAFPP) became interested and multiplied the improved varieties for distribution to farmers. Recently, however, African governments' interest in the rapid multiplication and distribution of IITA-improved cassava varieties has added a new impetus to the adoption rate by farmers in almost all of sub-Saharan Africa.

In Malawi, an IITA cassava multiplication and distribution project funded by the United States Agency for International Development (USAID) has successfully taken off. Also, there is the FAO/IITA and East and Southern African Rootcrops Research Network (ESARRNET) helping to spread IITA improved cassava varieties to farmers. The network which is being funded by FAO covers all countries in East and Southern Africa. In Nigeria, Benin, Cameroon, Zaire, Ghana, Mozambique, Niger, Guinea, Angola, Rwanda, Uganda, Togo, Tanzania, Sierra Leone, and Zimbabwe , there is an assurance of a new wave of cassava production that will go a long way to alleviate the food situation in the continent.

The early realization of this feat will depend largely of course, on the individual government's positive approach toward assisting farmers in procuring improved planting materials and educating farmers on the new processing techniques to eliminate or minimize loss.

Already, some of the countries are on the right path. In Nigeria, for example, both the government and farmers are taking advantage of IITA's proximity to adopt new technologies on cassava production and utilization. Since 1990, FAO figures have consistently shown Nigeria as the world's largest cassava producer - moving from its fourth rank to beat Brazil, Thailand and Zaire to the second, third and fourth positions. The achievement-according to FAO-is largely due to the availability of improved varieties from IITA.

A favorable factor is the Nigerian government's creation of a conducive atmosphere for cassava expansion and spread. In 1986, the Nigerian government introduced the Structural Adjustment Program (SAP) and banned the importation of rice, wheat and maize thereby encouraging farmers to increase local food production. At the same time, the government adopted aggressive and positive campaigns to popularize the improved cassava varieties, urging all relevant national institutions to embark on the multiplication and distribution of cassava planting materials in the rural areas.

Also, UNICEF, the International Fund for Agricultural Development (IFAD), and international non-governmental organizations became fully involved in the multiplication and distribution program.

After a five-year multi-locational testing program spanning all the cassava growing areas, Ghana recommended last year three of the best IITA cassava varieties for adoption by farmers in that country. The varieties TMS 30572, TMS 4(2)1425, and TMS 50395 were given local names that mirror their characteristics and food qualities both in the farmers' fields and when processed,.

In addition, early this year, private companies in Ghana who are desperate for planting materials made a request to IITA to supply cassava planting materials valued at about $35,000 from accredited Nigerian farmers and seed companies. After years of testing in which IITA's improved cassava varieties outscored all available materials, the Ugandan government in April officially recommended to farmers three IITA varieties for massive adoption.

To beat the drought problems in Mozambique and other Southern countries, IITA has promptly introduced germplasm adapted to the high altitude and drier ecologies from CIAT for testing and selection in the sub-region of the affected countries. Following the bitter experience suffered by Zimbabwe as a result of the 1992/93 drought that seriously affected that country's maize production, an S.O.S request was sent to IITA to recommend what other crops could be planted to cope with such an emergency situation. IITA recommended cassava as an alternative to maize to safeguard the interest of peasant farmers and prevent any calamity in future.

As a vegetatively propagated crop, cassava multiplication is generally slow. However, as a result of the crop's potential in alleviating hunger and malnutrition, rapid multiplication techniques are being developed by IITA scientists to cope with the demand.

If the present awareness on cassava adoption is sustained by farmers in sub-Saharan Africa, it is believed that-given adequate government support-the food situation will soon improve.

Apart from the procurement, production and utilization strategies, the governments need to organize and put in place extension strategies that facilitate the spread and adoption of improved varieties. They should provide good access roads to the rural areas. Governments should also embark on good marketing.


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