Cassava : Nigeria's untapped Goldmine

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Written by Jamila Mai Iyali

Cassava is a perennial woody shrub with an edible root, which grows in tropical and subtropical areas of the world. Cassava has the ability to grow on marginal lands where cereals and other crops do not grow well; it can tolerate drought and can grow in low-nutrient soils. Because cassava roots can be stored in the ground for up to 24 months, and some varieties for up to 36 months, harvest may be delayed until market, processing, or other conditions are favorable.

Cassava is the basis of many products, including food. In Africa and Latin America, cassava is mostly used for human consumption, while in Asia and parts of Latin America it is also used commercially for the production of animal feed and starch-based products.

In Africa, cassava provides a basic daily source of dietary energy. Roots are processed into a wide variety of granules, pastes, flours, etc., or consumed freshly boiled or raw. In most of the cassava-growing countries in Africa, the leaves are also consumed as a green vegetable, which provides protein and vitamins A and B.

In Southeast Asia and Latin America, cassava has taken on an economic role. Cassava starch is used as a binding agent, in the production of paper and textiles, and as monosodium glutamate, an important flavoring agent in Asian cooking. In Africa, cassava is beginning to be used in partial substitution for wheat flour.

According to Food and Agriculture Organization (FAO) estimates, 172 million tones of cassava were produced worldwide in 2000. Africa accounts for 54%, Asia for 28%, and Latin America and the Caribbean for 19% of the total world production. In 1999, Nigeria produced 33 million tones making it the world’s largest producer.

In terms of area harvested, a total of 16.8 million hectares was planted with cassava throughout the world in 2000; about 64% of this was in sub-Saharan Africa.

The average yield in 2000 was 10.2 tons per hectare, but this varied from 1.8 tons per hectare in Sudan to 27.3 tons per hectare in Barbados. In Nigeria, the average yield was 10.6 tons per hectare.

In Africa, cassava is mostly grown on small farms, usually intercropped with vegetables, plantation crops (such as coconut, oil palm, and coffee), yam, sweet potato, melon, maize, rice, groundnut, or other legumes. The application of fertilizer remains limited among small-scale farmers due to the high cost and lack of availability. Roots can be harvested between 6 months and 3 years after planting.

The major pests of cassava in Africa are the cassava green mite, the cassava mealy bug, and the variegated grasshopper. The main diseases affecting cassava are cassava mosaic disease, cassava bacterial blight, cassava anthracnose disease, and root rot. Pests and diseases, together with poor cultural practices, combine to cause yield losses that may be as high as 50% in Africa.

The production of cassava is dependent on a supply of quality stem cuttings. The multiplication rate of these vegetative planting materials is very low compared to grain crops, which are propagated by true seeds. In addition, cassava stem cuttings are bulky and highly perishable as they dry up within a few days.

As a root crop, cassava requires considerable labor to harvest. Because they are highly perishable, roots must be processed into a storable form soon after harvest.

Many cassava varieties contain cacogenic glycosides, and inadequate processing can lead to chronic toxicity. Various processing methods, such as grating, sun drying, and fermenting, are used to reduce the cyanide content.

Nigeria produces more cassava than any other country in the world. The crop is abundant in 24 of the 36 states, requires minimum labor and inputs, and remains the most important food security crop for millions of Nigerians. Yet every year at least USD 680 million of flour, starch, glucose, and animal feed are imported to Nigeria, most of which can be made from processed cassava. This is largely due to the fact that coordinated harvest and transport for large quantities of commercial grade cassava remain the greatest challenge for Nigeria to increase processing.

Scientists have played a leading role in the development of improved cassava varieties which are disease- and pest-resistant, low in cyanide content, drought-resistant, early maturing, and high yielding. The improved varieties have been introduced throughout Africa’s cassava belt. Varieties with resistance to the major diseases give sustained yields of about 50% more than the local varieties. Today, 60% of the area cropped with cassava in Nigeria is planted with improved varieties and Nigeria is the current world leading cassava producer. Impact studies have revealed that in Nigeria the introduction of improved varieties has provided food for 50 million people. The benefits of the improved varieties are not limited to Nigeria; improved cassava varieties are now used in most cassava-growing countries in Africa.

These improved Cassava varieties are the products of a scientific breakthrough referred to as Genetic Engineering. Genetically Modified Foods are now grown in Nigeria and are also imported. The International Institute for Tropical Agriculture (IITA), Ibadan, is the champion in the creation of genetically modified organisms (GMOs) with which the genetically modified foods (G.M. Foods) are produced. The institute has been creating GMOs and distributing them. E.g., cassava stems given to local farmers.

The IITA plans another field testing of G.M. cassava that was created by Professor Richard Sayre and others in 2013. The research and development was funded by more than $12.1 million in grants from the Bill & Melinda Gates Foundation. The cassava will provide all the proteins, vitamins, and minerals that people can get from eating a lot of different foods—a food culture known as “balanced diet”—in one cassava-based meal.

Other research and development institutes in Nigeria, including the National Root Crops Research Institute, Umudike, and the Federal Institute of Industrial Research Oshodi(FIIRO) are also involved in GMO creation. The Federal Ministry of Science and Technology is promoting it through its National Biotechnology Development Agency (NABDA), Abuja. Farmers in villages now know that the use of GMOs for farming will make their crops produce plenty foods which they can sell and earn not less than five million naira every year. It is also clear to them, that Genetically Modified Foods, such as cassava, peal easier, take shorter time to cook, and are testier.

The new biological control program has for a number of years been working to solve pest problems in cassava using natural and environmentally friendly methods. The program has been a major player in the successful biocontrol of the cassava mealy bug and cassava green mite. Through the introduction of natural enemies, there has been a 95% reduction in cassava mealy bug damage and a 50% reduction in damage caused by the cassava green mite.

To overcome cassava’s low multiplication rate, the scientists have developed a technique to make 2-node cuttings or minis takes that can make 50 plants from each parent cassava instead of 10 stakes as before. These minis takes are easily moved and protected in plastic sacks until they can be grown on and hardened in individual plastic bags or nursery beds before being planted in the field.

In the area of postharvest, the scientists have been developing effective and simple machines and tools which reduce processing time and labor, as well as production losses. With these machines, losses can be reduced by 50% and labor by 75%.

During the past three decades, they have trained more than 9000 researchers and technicians in Africa. For example, they have carried out training in processing and utilization of quality cassava flour in 10 African countries. As a result, the private sectors in Madagascar, Nigeria, Tanzania, and Uganda have begun using quality cassava flour as a raw material for processing into secondary products such as biscuits and noodles.

This recent efforts are helping farmers generate over USD 1.6 million from the sale of cassava root and are assisting processors to generate revenue of over USD 6.1 million from the sale of processed cassava.

Cassava tuber may be processed into a variety of products which are hot cakes in the export market. These include chips, flakes, cubes, peeler, starch and flour, pellets, etc. Many European and American countries, including: Germany, UK, France, the Nertherlands among others demands huge quantities of processed cassava products annually. In fact, the use of cassava for compounding livestock feeds has gained wide acceptance in Latin America and Asia. There is booming export market and the European Economic Community (EEC Countries) import over 10 million metric tons per annum

Apart from livestock feeds, processed cassava serves as industrial raw material for the production of adhesives bakery products, dextrin, dextrose glucose, lactose and sucrose. Dextrin is used as a binding agent in the paper and packing industry and adhesive in cardboard, plywood and veneer binding.  

Food and beverage industries use cassava products derivatives in the production of jelly caramel and chewing gum; pharmaceutical and chemical industries also use cassava alcohol (ethanol) in the production of cosmetics and drugs. The products also find ready use in the manufacture of dry cell, textiles and school chalk etc. Cassava cubes are used mainly in the compounding of livestock feeds. Thus there is a very high demand for cassava products in both the local and export markets.