Cassava plants and storage roots.
Cassava being a valuable subsistence and cash crop in many countries, its agricultural potential in South Africa needs to be fully exploited. Although cassava has had a long history in the rest of Africa, cassava is not a well-known crop in South Africa. In South Africa, cassava is produced on a few commercial farms of <5,000 hectares and in small fragmented areas, with limited technologies and under low input farming system. Cassava farming is becoming more attractive due to the diverse use of cassava products in the country and the diminishing potential of other crops such as sugar cane.
Cassava's starchy roots are a major source of dietary energy for more than 800 million people. According to the United Nations Food and Agriculture Organization (FAO), cassava ranks fourth as a food crop in the developing countries, after rice, maize and wheat. The leaves are relatively rich in protein and can be consumed as leafy vegetable. Cassava can be stored in the ground for several seasons, thereby serving as a reserve food when other crops fail. Cassava is also increasingly used as an animal feed and in the manufacture of different industrial products.
According to FAO estimates, 304 million tonnes of cassava was produced worldwide in 2020. Africa accounted for 64%, Asia for 27%, and Latin America and the Caribbean for 9% of the total world production. Cassava is grown in more than 104 counties; Nigeria, Democratic Republic of the Congo, Thailand, Ghana, Indonesia and Brazil are the leading cassava producers. A total of 28.2 million hectares was planted with cassava throughout the world in 2020; about 80% of which was in sub-Saharan Africa. Although Africa accounts for more than 64% of cassava production and more than 80% of land area cultivated for cassava, the average fresh root yield of cassava is 9.5 t ha−1 , which is far lower than the world average (11.8 t ha−1 ) and the yield observed in Asia (24.1 t ha−1).
Many reports indicated that the demand for fresh and industrial cassava products exceeded the current production capacity. Quality, price and year-round availability of products are important considerations to get market access. However, the traditional small-scale processors in Africa do not meet the minimum quality standard demanded by the international users. Studies conducted in east and southern Africa suggested that there is a huge, latent and unexploited market potential for cassava in the areas of food (fresh, waxed and frozen roots, fresh and frozen leaves, flour), feed (dried chips, leaf meal and pellets), energy (biofuel) and starch (native, modified, sweeteners).
Cassava is the basis of a multitude of products, including food, flour, animal feed, alcohol, starches for sizing paper and textiles, sweeteners, prepared foods and bio-degradable products. The products are derived from a number of forms of cassava, ranging from fresh leaves and roots to modified cassava starch. The degree of processing and the technical requirements tend to increase from the fresh form to the modified starch form. These products represent potential market development opportunities for cassava.
Fresh roots and leaves are used primarily as human food. Roots are highly perishability, traditional methods for preserving fresh roots include packing roots in moist mulch or removing leaves two weeks prior to harvest to increase root shelf life to two weeks. In Colombia, CIAT researchers found that preservative treatments such as dipping fresh roots in wax or paraffin and storing them in plastic bags reduced vascular streak and prolonged storage for 3 to 4 weeks. Roots can be peeled, chopped into chunks and frozen for specialized markets. Cassava leaves can be eaten as a fresh vegetable, ground fresh and frozen in plastic bags, or dried and ground for sale in plastic bags. The leaves are more nutritionally balanced than the roots and can help to prevent certain deficiency diseases.
In many countries of Africa and Latin America, cassava is processed at home or at village level to produce flour (farinha in Brazil, gari in West Africa), or to make flat bread (casabe in the Caribbean). Farinha and gari can be produced in both small- and large-scale operations. Dried cassava has been a major success as an animal feed ingredient in Europe and as an export product in Thailand and Indonesia. Thailand, China, Brazil and Paraguay are also reportedly using a substantial proportion of their cassava for non-intensive swine, poultry and fish production. Technical details for using dried cassava in rations are well established in milling and blending and in animal nutrition
Convenience foods that are easy to buy, store and prepare are demanded by the market because of the busy life style. Thus, packaged cassava and cassava flour and breads are gaining greater acceptance in some markets. Farinha and gari in particular could be considered as convenience foods because they are easy to buy, store and prepare. Cassava flour has a huge potential in many developing countries, particularly in Africa and Asia where there is a large consumption of bread made from 100 per cent imported wheat. Dried cassava in the form of meal, chips and pellets is an important animal feed ingredient. As livestock production and meat consumption become more important in South Africa, the need for animal feed rations is expected to increase. Finally, dried and fresh cassava can be used to produce glues and alcohol.
Cassava starch is used directly in different ways or as a raw material for further processing. Special features of cassava starch are its viscosity, resistance to shear stress and resistance to freezing. The main classes of starch-based products are:
(i) unmodified or native starch;(ii) modified starches for industrial purposes; and (iii) sweeteners (dextrin, monosodium glutamate, pharmaceuticals, etc.).
(i) unmodified or native starch;
(ii) modified starches for industrial purposes; and
(iii) sweeteners (dextrin, monosodium glutamate, pharmaceuticals, etc.).
One of the constraints hampering the exploitation and diffusion of cassava is the lack of awareness and lack of public and private sector investment. Exploitation of global market opportunity require public-private partnership. Policies should foster public-private partnerships for technology development, agro-processing and marketing of cassava to facilitate the scaling up of successful innovations.
Although the South Africa cassava industry association (CIASA) was established under the Department of Trade, Industry and Competition (DTIC), currently the association is not active. DTI should revive the association by revisiting the constitution and the members and its role should be redefined to support the cassava industry in South Africa and to include all the value chain actors.
The production, characterization and product development from cassava is at its infancy in South Africa compared to other African countries. Cassava production is dominated by disease-prone varieties with long maturation periods and low yield potential. There is a need to establish sustainable genetic resource management system that focuses on the characterization, conservation and utilization of cassava genetic resources. It is also wise to exploit the available genetic and genomic resources that have been developed in many national and international research organizations by establishing strong collaborative links.
Market creation and product diversification should be important to assimilate cassava in the present production system and facilitate cassava commercialization and agro-processing. In most of the African countries, the supply chain for cassava products begin with small-scale production units, followed by small-scale processing units for the drying and/or milling of cassava. These steps are often carried out at the home and village/local level. As the market grows the supply chain activities such as marketing, processing and packaging are done by fewer larger-scale units. The existence of the hourglass supply chain does suggest that the growth and development of cassava product markets will benefit the large number of resource-poor farmers located on poor lands as well as the local processing units.
The challenge is how to equip these farmers and processors with the knowledge and tools needed to provide the products that meet the requirements of growth markets. Training is an integral part of any development activity and a process by which acquiring new knowledge, skills, practices, and attitude in the context of preparing farmers for improving agricultural productivity. Training plays a key role in human capacity development, to equip farmers with skills, knowledge and competencies for sustainable crop production, resource utilization, and income generation.
The development of the cassava industry can contribute to food and income security, job creation and revitalization of the rural sector. Public investment in cassava R&D and product development played a vital role in reducing food insecurity, malnutrition, unemployment, and urban migration.
Amelework AB, Bairu MW, Maema O, Venter SL & Laing M. 2021. Adoption and promotion of resilient crops for climate risk mitigation and import substitution: A case analysis of cassava for South African agriculture. Frontiers in Sustainable Food System. 5: 617783.