Knowledge for Development

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Improving cassava production

    Is cassava the crop of the future for food and nutrition security and industrial development? Not unless, we increase investments in science, technology and innovation. An interesting presentation on the Global Cassava Partnership for the 21st century (GCP 21) by Dr Claude Fauquet at CTA Headquarters on 28 March 2013 triggered further reflection on the need for a coordinated approach to cassava development.     Dr Fauquet indicated that 105 countries produce cassava; 50% of which are in Africa where surface area is almost double that of Asia and Latin America. However, yield is lower (10t/ha) as compared to 12t/ha and 19t/ha in Latin America and Asia, respectively. What is the role of African universities and research organisations in driving the research and development agenda for cassava on the continent? Which organisations are studying future consumer and industry trends for cassava?     Which are leading programmes on: (i) documenting and characterising cassava landraces, farmer knowledge and practices; (ii) the performance of various varieties and landraces under changing climatic conditions including for drought and pest resistance; (iii) new product development for food and other industrial uses; (iv) increasing yield potential; (v) standardising height of plants (dwarf varieties) and size of roots to support industry expansion for food products, starch or animal feed etc.?     Work is going on at some leading international centres and in collaboration with national R&D organisations to produce virus-free varieties through genetic engineering and on rapid multiplication but while these are critical research areas, the success of a cassava ‘green revolution’ in Africa or world-wide requires interlinked thinking, an innovation systems approach, foresight, investments in science and engineering, an enabling policy and institutional framework and visionary leadership from scientists/academicians, policy/governments and the private sector including farmers.--Visit the Cassava dossier at http://knowledge.cta.int/Dossiers/Commodities/Cassava--Get the presentation by Dr Claude Fauquet at http://knowledge.cta.int/Dossiers/CTA-and-S-T/Selected-publications/Improving-cassava-production--To post comments, see the guide at http://knowledge.cta.int/Blogs/How-to-create-a-blog-Comment-participer-aux-debats--

11/04/2013


Genetic diversity among farmer-preferred cassava landraces in Uganda

This study was carried out to determine genetic diversity within and among 51 farmer-preferred cassava (Manihot esculenta) landraces and 15 elite accessions grown in Uganda. The genetic diversity assessment in this study revealed that 24% of a total of 154 alleles were unique alleles present only in landraces. Including these landraces with unique alleles in cassava breeding schemes will increase the chances of producing farmer preferred adapted elite cultivars. The study also revealed genetic differentiation among accessions from different regions providing an opportunity for establishment of heterotic pools within a breeding programme. (African Crop Science Journal, Vol. 20, 2012) 

10/04/2013


A study of perennial staple crops

The Overstory, journal of Agroforestry Net (www.agroforestry.net, based in Hawaii, US), features an extended excerpt of the in-depth review of perennial staple crops conducted by Eric Toensmeier of PerennialSolutions.org. Perennial staple crops include grains, pulses (dry beans), nuts, dry pods, starchy fruits, oilseeds, high-protein leaves, and some more exotic products like starch-filled trunks, sugary palm saps, and aerial tubers. These offer the unique possibility of crops grown for basic human food that can simultaneously sequester carbon, stabilize slopes, and build soils as part of no-till perennial agricultural systems. Such production models approach the carbon sequestering capacity of natural forest, because they can mimic the structure of a forest most closely. Perennial staple crop systems are resilient in the face of climate change effects better than most annuals. These food forests can be long-lived, no-till, and low-maintenance. They do however have harvesting and processing challenges – for example most peach palm varieties have tall, very spiny trunks that must be climbed for harvest. The review describes perennial crop candidates by climate types, details the barriers to their adoption, compares their carbohydrate and protein yields with annual crops, and identifies the members of each perennial plant family (Palm, legume, mulberry, banana, yam along with hardy nuts and grasses).http://agroforestry.net/overstory/overstory248.html(The Overstory #248, 13/8/2012)

26/09/2012


Commercial cassava production

The Caribbean Agricultural Research and Development Institute (CARDI) Technical Bulletin, Commercial cassava production 2011, is now available on the CARDI website. This bulletin updates the first edition of the factsheet, Commercial Cassava Production written by Frances Chandler in 1989 and reprinted in 1992.

12/07/2012


World’s top cassava researchers meet to address the challenge of climate change

Co-Founders of the Global Cassava Partnership for the 21st Century Dr. Claude Fauquet, Principal investigator at the Danforth Plant Science Center and Director of International Laboratory for Tropical Agricultural Biotechnology (ILTAB, St. Louis, USA) and Dr. Joe Tohme of CIAT in Cali (Colombia) gathered 29 prominent agricultural researchers from 14 countries, representing 17 cassava research institutions in Africa, Asia, Latin America, Europe, and North America for a three day conference in Italy, to discuss the impact of climate changes on the security food crop cassava. Experts at the conference explained how climate changes are likely to increase cassava production. New reports suggest that increases in atmospheric CO2 levels could lead to gains in yield and significant increases in the total acres dedicated to planting cassava. In addition, more frequent drought throughout most of Africa will not negatively impact cassava production like maize. Consequently, the land area dedicated to growing cassava is expected to continue to expand in the 21st Century. On the other hand, elevated rainfall in some areas will result in more disease pressure, and increased temperatures will exacerbate insect and mite infestations as well as viral diseases that have a major impact on cassava yield. These critical issues confirm the need for further research and investment in the cassava. (Source: CIAT, 1 December 2010.)

14/02/2011


Cassava sequence unravelled

Scientists have sequenced the genome of the staple crop cassava, and say this should lead to the development of more virus-resistant and nutritious varieties. The draft genome, of a single cassava variety, has pinpointed about 95 per cent of the genes and could accelerate breeding programmes. The large roots of the cassava plant provide daily sustenance for more than 750 million people in Africa, Asia and Latin America. But the crop is susceptible to many viruses and is not very nutritious. Steve Rounsley, associate professor at the School of Plant Sciences at the University of Arizona, who coordinated the project, says the sequence will make goals such as developing virus resistance and increasing shelf life more attainable. A US$1.3-million follow-up project, funded by The Bill and Melinda Gates Foundation, will sequence other cassava varieties and develop a freely available database comparing the sequences. The University of Arizona will lead the project which will involve international collaboration, including some African partners. (Source: Scidev.net, 23 November 2009)

8/12/2009


Equipment for cassava processing plants

Agromachine Importacao e exportacoa ltda in Brazil is a global provider of machines, solutions and services for agriculture. The company's services are focused primarily within the coffee, rice, cassava, maize and tropical products industry and specialize in providing processing equipments to customers globally. The company has developed excellent equipment for cassava processing plants.

30/10/2007


GM Cassava Has 'Super Size' Roots

A research team led by Richard Sayre of OhioStateUniversity in the U.S. has developed genetically modified (GM) cassava plants that produce "dramatically bigger" roots and more leaves. Cassava roots are a staple food for about 600 million people in Africa, Asia, and Latin America. The leaves are also eaten in Africa as a source of protein, minerals, and vitamins. Sayre says he hopes that there will be interest in releasing the GM cassava to Africa free of charge. The research results were published May 5 in Plant Biotechnology Journal.  More information

9/06/2006


Development of a fermentation medium and detection bioassay for the local production of the antihelminthic antibiotic avermectin

Locally available fermentation media for the production of avermectin by Streptomyces avermitilis in the Philippines were examined. The following substrates were tested: all-purpose flour, cane sugar, and cassava starch. Cassava starch was the best substitute for soluble starch. Baker's yeast was established as a better substitute for cottonseed flour than soybean meal. Restricted random balance design experiments were performed on the modified production medium 8 (MPM 8), resulting in an optimized formulation of MPM 8 consisting of cassava starch, baker's yeast, potassium phosphate and zinc sulphate. A bioassay procedure for the determination of avermectin activity using the brine shrimp ( Artemia franciscana) was established. The sensitivity of the developed bioassay procedure was not determined. However, at 0.0001 mg/ml avermectin concentration, 40% cumulative mortality was observed. Philippine Agricultural Scientist (Philippines). 2000, v. 83(4) p. 348-356

5/04/2006


The starch industry: its commercial potential

The prospects for increased starch production in Malaysia are examined. The main local sources of starch are cassava and sago. Cassava starch production in Peninsular Malaysia has been on the decline since the 1970s, mainly due to an inadequate supply of cassava. Sago starch production is confined mainly to Sarawak. Sweet potato and banana have not been exploited as sources of starch. There is a strong and growing demand for starch in Malaysia. Starch is used mainly in the manufacture of monosodium glutamate, glucose and paper products, and also in yeast, small foods, textiles and laundry industries. There are many other uses of starch in its native or modified forms. The main constraint to cassava cultivation is the need for large enough tracts of land that are amenable to mechanization. The drier areas in Sabah may provide such land. Much of the basic knowledge in agronomy for sago cultivation as well as quality planting materials is still lacking. Sweet potato and banana do not yet have flour and other downstream processing industries in Malaysia to create a demand for their expanded cultivation. There is a need to raise public awareness on the possible uses of sweet potato and banana flour. From authors' summary. Planter (Malaysia), v. 78(918) p. 485-494

5/04/2006


Concept test of value-added root crops

In Guam, a concept test was conducted to assess local awareness of traditional root crops and to study the market potential for value-added products made from taro, sweet potato and cassava. The test design was a self-evaluating survey that was used to explore: (1) the level of consumption of chips and baked/fried foods; (2) the interest level of foods made from root crops; and (3) the level of interest of "Made in Guam" products. In a survey conducted from March to May 2000, 130 respondents between the ages of 18-54 representing Guam's consumer population were analysed. The most popular type of value-added product was sweet potato chips, followed by sweet potato bread, cassava cake, cassava pudding and cassava tamales. Of the 130 persons surveyed, 72% had consumed sweet potato within the past 3 months, while more than 60% had eaten cassava and 55% had eaten taro. Results suggest that there is a market potential for value-added foods made from these tropical root crops. The survey also shows that there is interest in "Made in Guam" foods. From authors' summary. Micronesica University of Guam (USA), v.34 (suppl.7) p. 41-53

5/04/2006


Challenging Bennet's law: the new economics of starchy staples in Asia

In Asia, the role of tropical root and tuber crops (R&T) is changing from being food staples to sources of raw materials for processed food products and animal feed. The growing utilization of R&T in these expanding markets depends critically on their price competitiveness relative to other commodities, especially maize. Price relationships among commodities in Asia are examined to assess the potential of cassava and sweet potato in starch and feed markets. For starch, cassava is currently competitive in South-East Asia. Sweet potato is only competitive in markets that require the special starch traits found in this crop. Plant breeding to increase starch yield from cassava and sweet potato would improve their competitiveness in Asian markets. In the manufacture of least-cost pig feed mixes, the results of a linear programming model show that most millers in China, Indonesia, the Philippines, Thailand and Vietnam are likely to prefer maize over R&T due in part to the higher cost of protein supplements when using starchy R&T. However, a cassava + soybean compound feed appears to be currently economically viable in Thailand. Sweet potato and cassava are also viable feed options for many small farmers who grow their own feed so long as the protein-rich foliage can be effectively incorporated along with starchy roots in feed rations. From abstract Elsevier Science Journal. Food Policy (UK), v. 29(2) p. 187-202

5/04/2006


Caribbean: Manufacturing procedures and microbiological aspects of parakari, a novel fermented beverage of the Wapisiana Amerindians of Guyana

The alcoholic beverage parakari, a unique fermentation product of cassava ( Manihot esculenta) made by the Wapisiana of Guyana, involves the use of a starch hydrolysing (amylolytic) mould (Rhizopus sp., Mucoraceae, Zygomycota) followed by a solid-state ethanol fermentation. A detailed study was made of the parakari manufacturing process in a Wapisiana village in South Rupununi, Guyana. Thirty steps were involved in parakari manufacture and these exhibited a high degree of sophistication, including the use of specific cassava varieties, control of culture temperature, and boosting the inoculum potential with purified starch additives. Changes in glucose content, pH, taste, smell, and culture characteristics during the fermentation process were observed. Parakari is the only known example of an indigenous New World fermentation process that utilizes an amylolytic mould. The manufacture of parakari is analogous to similar dual fermentations of the Orient, yet independently derived. From author's summary. Economic Botany (USA), v. 58(1) p. 25-37

5/04/2006


Africa: Foods from cassava and their relevance to Nigeria and other African countries

There are few food products from cassava that are processed industrially with added value that will be of higher nutritional value and have longer shelf-lives. There are a number of traditionally-processed staple foods from cassava in Nigeria and other African countries that need improvement. Most of these foods can be improved on if the market for them is assured by the end-users, a market that is currently lacking. It will be necessary to create more public awareness within Nigeria and other African societies to increase the acceptability of such novel products and this requires a multidisciplinary approach to interpret what scientists and technologists are doing to the old crop in the present age. From authors' summary. Agriculture and Human Values (USA), v. 18(4) p. 383-390

5/04/2006


Africa: Innovations and diffusion of food products in Africa: attieke (fermented cassava) in Benin

In Cotonou, the economic capital of Benin, the technical systems used for processing "attieke", a cassava-based food product, and marketing activities that have been developed around attieke, were studied. The population of Cotonou is comprised of a mix of people from different parts of Benin and other African countries. Until about 5 years ago, attieke which is "couscous" made from cassava from the Ivory Coast was mainly eaten in "maquis", small restaurants run by women comprising a few tables in the home and restaurants whose only supply was that of imported attieke. For the last few years, women from Benin and the Ivory Coast have been producing the Ivory Coast type of attieke commercially, which has meant that people are now eating it at home. As a result of the emergence of this "new" food sector, a Beninese substitute ("attieke gari") is now being produced. This has been accepted much more quickly because the process is simpler and the product is more affordable for consumers. The income generated by processing attieke, be it the Ivory Coast type attieke or its Beninese substitute, is sufficient to satisfy a family's basic needs (schooling, food, clothing, rent). The market study in Cotonou revealed that consumption in the home is still low but that attieke consumption is on the increase in fast-food restaurants, particularly with the emergence of attieke gari.

5/04/2006


Africa: Genotype x environment interaction effects on native cassava starch quality and potential for starch use in the commercial sector

In 2000, genotype x environment interaction effects on the quality of starch of 6 local cassava varieties were compared with those of 9 introduced clones in Chitedze and Makoka, Malawi, to examine the potential of cassava starch for industrial use in Malawi. It was found that the moisture and ash contents were much lower than the recommended allowable maximum. The pH for cassava starch was within the recommended range. Additive main effects and multiplicative interaction (AMMI) strongly correlated with other stability parameters such as Wi-ecovalence and stability variance. Genotype had a greater influence on root dry matter than the environment. It was concluded that native cassava starch could be used in the pharmaceutical, battery and packaging material making and textile industries in Malawi. From authors' summary. African Crop Science Journal (Uganda), v. 12(3), special issue, p. 205-216

5/04/2006


Africa: Briquetting of rattan furniture waste from cassava

The production of briquettes from chopped rattan strands mixed with cassava starch paste (CSP) was studied. Samples of rattan strands of mixed species ( Laccosperma secundiflorum and Eremospatha macrocarpa) were collected from a furniture workshop in Oyo, Nigeria. The strands, having an average moisture content of 12% and an average dimension of 630 mm (length) by 4.0 mm (width), and 1.8 mm (thickness), were reduced to 25 mm (length) by 4.0 mm (width) and 1.8 mm (thickness) particles by manual shearing. They were subsequently mixed with CSP at 6 proportions by weight, i.e. 50, 100, 150, 200, 250, and 300%. The minimum proportion by weight of cassava starch required for briquette formation was 200%. Compression experiments were performed using a simple tabletop closed-end die piston press fitted with both a pressure and a dial gauge. Four levels of pressure application: 3.5, 7.0, 10, and 14 N/mm2), and 2 loading durations (dwell times; 3 and 5 min) were employed. The minimum pressure required for briquette formation was 14 MPa. The specific energy required to form the rattan strand briquettes at 200, 250 and 300% cassava starch content levels was 8, 9.3 and 11.1 J/t, respectively. All the expansion (minimal in all cases) of the briquettes took place within 30 min. It was concluded that stable briquettes could be formed from rattan strands mixed with CSP. From author's summary. Journal of Bamboo and Rattan (Netherlands), v. 3(2), p. 139-149

5/04/2006


Cassava: immense development potential

Cassava, grown mostly by small subsistence farmers, is a food crop for 500 million people. It is the highest starch yielder per unit of area, and its harvest can be delayed over several months by leaving the roots in the soil. The roots are processed in many ways and the young leaves are eaten as a vegetable. Yields are about 11 t/ha but potential production levels amount to 40 t/ha. These low yields are due to bad cultural practices and insufficient crop protection measures. World production is evaluated at 153 million t, half of which is produced in Africa. Thailand and Indonesia export chips and flour of cassava. Cassava will become more and more a commercial crop, with incorporation of the smallholders as producers. The development of export markets is hampered by the absence of processing technologies. The different ways to develop a cassava industry, including the transfer of processing technologies, breeding of high-yielding varieties, amelioration of cultural practices, and ways to dispose of the processing waste are discussed. Marches Tropicaux et Mediterraneens (France), no. 2696, p. 1553-1555

5/04/2006


Proper preparation of cassava flour

A manual on the proper preparation of cassava flour is provided. It describes how the production of cassava flour can generate income and make the preparation of food cheaper and more diversified, thanks to improved processing techniques and new recipes. It is designed for extension workers and grass roots non-governmental organizations, especially those working with women. Subjects include: (1) constraints to traditional cassava flour production; (2) methods to produce unfermented top quality cassava flour; (3) use of cassava flour in private households and in the food industry; (4) extension issues; (5) establishing a cassava flour production unit; and (6) operating a cassava flour production unit. Apart from traditional dishes, cassava flour also possesses a considerable and so far underexploited potential as an additive or even as a substitute to wheat, maize and other flours that are often imported. Root and Tuber Development Guides, no.3

5/04/2006


Some physico-chemical characteristics of modified cassava starches presenting baking property

The effect of starch modification by oxidation on the baking qualities of cassava was investigated. Starch oxidation was achieved with K permanganate. This was followed by lactic (LACW) or citric (CITW) acid treatments. The samples were washed with de-ionized water and evaluated in relation to their expansion properties, carboxyl contents, hot paste behaviour, intrinsic viscosity, differential scanning calorimetry analysis and microscopy. Native cassava starch (NAS) as well as lactic acid-treated and oven- (LACOVW) or sun-dried (LACSUNW) samples were used for comparison. One sample of commercial cassava sour starch (SOUR) was also analysed. It was found that both chemically (LACW and CITW) and photo-chemically (LACSUNW and SOUR) modified samples presented useful baking properties, but not NAS and LACOVW. The carboxyl content was higher for the chemically oxidized samples indicating that they were more extensively modified. This was confirmed by methylene blue differential dyeing. Viscosity peaks decreased with increasing pH for the samples with baking property. These also presented the lowest intrinsic viscosities. The baking property of sour cassava starch is used for producing expanded gluten-free cookies. From authors' summary. Experimental Agriculture (UK), v. 39(2) p. 167-179

5/04/2006