Save And Grow: Cassava - Food And Agriculture Organization
copertina cassava save and grow.pdf125aprile201312.00CMYSAVE AND GROWSAVE AND GROW: CASSAVAThis guide is the first on thepractical application of FAO’s“Save and Grow” model ofagriculture to specificsmallholder crops and farmingsystems. It comes as cassavaproduction intensifiesworldwide, and growers shiftfrom traditional cultivationpractices to monocropping,higher-yielding genotypes, andgreater use of agrochemicals.Intensification carries great risks, including soil nutrientdepletion and upsurges in pests and diseases. The guide showshow ecosystem-based “Save and Grow” approaches and practicescan help tropical developing countries to avoid the risks ofunsustainable intensification, while realizing cassava’s potentialfor producing higher yields, alleviating hunger and rural poverty,and contributing to national economic development.CMMYCYCMYKA GUIDE TO SUSTAINABLE PRODUCTION INTENSIFICATIONFAO
Save and Grow:CassavaA guide to sustainable production intensificationFOOD AND AGRICULTURE ORGANIZATIONOF THE UNITED NATIONSRome, 2013
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ForewordCassava is a tropical root crop, originally from Amazonia, thatprovides the staple food of an estimated 800 million people worldwide. Grown almost exclusively by low-income, smallholder farmers,it is one of the few staple crops that can be produced efficiently on asmall scale, without the need for mechanization or purchased inputs,and in marginal areas with poor soils and unpredictable rainfall.Since 2000, the world’s annual cassava production has increased byan estimated 100 million tonnes, driven in Asia by demand for driedcassava and starch for use in livestock feed and industrial applications,and in Africa by expanding urban markets for cassava food products.There is great potential for further production increases – underoptimal conditions, cassava yields can reach 80 tonnes per hectare,compared to the current world average yield of just 12.8 tonnes.Booming demand offers millions of cassava growers in tropicalcountries the opportunity to intensify production, earn higherincomes and boost the food supply where it is most needed. But howsmallholder cassava growers choose to improve productivity shouldbe of major concern to policymakers. The Green Revolution in cerealproduction, based on genetically uniform varieties and intensive useof irrigation and agrochemicals, has taken a heavy toll on agriculture’snatural resource base, jeopardizing future productivity. In movingfrom traditional, low-input to more intensive cultivation, small-scalecassava growers should not make the same mistakes.Sustainable intensification of cassava production is the subject ofthis guide, the first in a series to the practical application of FAO’s“Save and Grow” model of agriculture to specific smallholder cropsand farming systems. Endorsed by FAO in 2010, “Save and Grow” is anecosystem approach to agriculture that aims at improving productivitywhile conserving natural resources. It promotes practices that canhelp the world’s half a billion smallholder farm families to producemore from the same area of land while enhancing natural capital andecosystem services.Drawing on two decades of research findings and on-farm experiences in Africa, Asia, Latin America and the Caribbean, the guidepresents an eco-friendly approach to managing cassava more intensively. Many recommended practices combine traditional knowledgewith modern technologies that are adapted to the needs of small-scale
iv Save and Grow: Cassavaproducers. They include: minimizing tillage to protect soil health,optimizing timing and methods of planting, and using biologicalcontrol agents to counter pests and diseases. The guide shows howwell-balanced applications of mineral fertilizer, in combination withintercropping, crop rotation, mulching, manure and compost, canmake a cassava-based farming system not only more productive andprofitable, but also more sustainable.The adoption of “Save and Grow” agriculture will require significantimprovements in the provision of extension, inputs and productioncredit to small-scale producers. Moreover, FAO recognizes thatimproved productivity may not bring about sustainable, long-termdevelopment outcomes: a major effort is needed to integrate smallholders into higher levels of value addition. Transforming cassava into amultipurpose subsector that generates income, diversifies economiesand ensures food for all will require political commitment, investment,institutional support and a demand-driven approach to technologydevelopment.This guide will be a valuable resource for policymakers in assessinghow a dynamic cassava sector can help them to achieve their goals ofpoverty alleviation, economic development and food security, and ofpractical use to agricultural researchers, technicians and other professionals in preparing programmes for sustainable cassava productionintensification.Clayton CampanholaDirector, FAO Plant Production and Protection Division
apter 1: Cassava, a 21st century cropChapter 2: Farming systemsChapter 3: Varieties and planting materialChapter 4: Water managementChapter 5: Crop nutritionChapter 6: Pests and diseasesChapter 7: Harvest, post-harvest and value additionChapter 8: The way forward119354959738797Annex tablesReferencesAbbreviations109121129
vi Save and Grow: CassavaAuthorsThis guide was prepared byReinhardt HowelerCIAT emeritus scientistNeBambi Lutaladioand Graeme Thomasof the FAO Plant Productionand Protection DivisionAcknowledgementsThe contributions of the following aregratefully acknowledged:Kolawole Adebayo (Abeokuta Universityof Agriculture, Nigeria)Jean Pierre Anota (FAO consultant)Tin Maung Aye (CIAT)Jan Breithaupt (FAO)Hernán Ceballos (CIAT)Swarup K. Chakrabarti (CTCRI, India)Mark Davis (FAO)Dominique Dufour (CIAT)Emerson Fey (State University of WestParaná, Brazil)Marjon Fredrix (FAO)Theodor Friedrich (FAO)Gualbert Gbehounou (FAO)Book designThomas SansonettiWinfred Hammond (FAO)Lawan Jeerapong (Departmentof Agricultural Extension, Thailand)Jippe Hoogeveen (FAO)Josef Kienzle (FAO)Lava Kumar (IITA)Chikelu Mba (FAO)Danilo Mejía (FAO)Linn Borgen Nilsen (FAO)Christian Nolte (FAO)Bernardo Ospina Patiño (CLAYUCA)Dai Peters (Great Lakes CassavaInitiative)Adam Prakash (FAO)Chareinsak Rojanaridpiched (KasetsartUniversity, Thailand)Teresa Sánchez (CIAT)Brian Sims (FAO consultant)Mario Takahashi (Agricultural Instituteof Paraná, Brazil)Namthip Thongnak (Thai TapiocaDevelopment Institute)Bernard Vanlauwe (IITA)Andrew Westby (Universityof Greenwich, UK)James Whyte (FAO consultant)Amporn Winotai (Departmentof Agriculture, Thailand)Cover and illustrationsCecilia SanchezEditorial assistanceDiana Gutiérrez
Overview1. Cassava, a 21st century cropThe “food of the poor” has become a multipurpose crop thatresponds to the priorities of developing countries, to trends inthe global economy and to the challenge of climate change.ong regarded as unsuitable for intensification, cassava hasgrown dramatically in importance in world agriculture. The2012 harvest reached record levels, thanks to expansion of globaltrade in cassava products and strong growth of output in Africa.Production is intensifying worldwide. In the years ahead, cassavawill see a shift to monocropping, higher-yielding genotypes, andgreater use of irrigation and agrochemicals. But intensificationcarries great risks, including upsurges in pests and diseases, anddepletion of soil nutrients. This guide shows how FAO’s “Save andGrow” farming approach can help developing countries to avoidthe risks of unsustainable intensification, while realizing cassava’spotential for producing higher yields, alleviating rural poverty andcontributing to national economic development.L2. Farming systemsMany smallholder cassava growers already practise threekey “Save and Grow” recommendations: reduced or zerotillage, soil surface cover and crop diversification.lanting cassava without prior tillage in degraded soils mayproduce lower yields in the initial years; once soil health isrestored, however, untilled land can produce high yields at alower cost to the farmer and the farm’s natural resources. Mulchand cover crops help to reduce weed infestations and createsoil conditions that improve productivity. Growing cassava inassociations, sequences and rotations increases net income perunit area of land, and reduces the risk of crop failure. Intercroppingwith grain legumes can produce higher incomes thanmonocropping, and supplies food for the household. Protectivehedgerows reduce soil erosion, while rotating cassava with legumesand cereals helps to restore soil health and yields.P
viii Save and Grow: Cassava3. Varieties and planting materialThe full potential of cassava will not be realized untilproduction constraints are mitigated in higher-yieldingvarieties, and cassava growers have access to disease-freeplanting material.he time is right for the genome-wide characterization ofcassava genetic diversity, to fill gaps in landrace collections,and to create natural reserves to safeguard wild relatives. Theharmonization of passport and evaluation data on genebankaccessions should be a priority. Breeding should focus ondeveloping varieties that are well-adapted to specific agroecologies, cropping systems and end-uses, and produce good yieldswith minimal need for agrochemicals and irrigation. The routinemultiplication and distribution of disease-free planting materialof improved varieties are essential for sustainable intensification.While few countries have formal seed systems for cassava, a 3-tiercommunity-based system pioneered in Africa, involving NGOsand farmer associations, has helped ensure that improved varietiesand healthy planting material are adopted by cassava growers.T4. Water managementOnce established, cassava can grow in areas that receivejust 400 mm of average annual rainfall. But much higheryields can be obtained with higher levels of water supply.ptimizing rainfed cassava production requires carefulattention to planting dates, planting methods and plantingpositions, and soil management practices that help to conservewater. Although it can grow in areas with 400 mm of rainfalla year, maximum root yields in Thailand were correlated withrainfall totalling about 1 700 mm. Cassava responds well toirrigation – full surface irrigation has doubled the root yieldobtained without irrigation; drip irrigation can produce aboutthe same yield as surface irrigation using 50 percent less water. InNigeria, root yields increased sixfold when the quantity of watersupplied by supplementary drip irrigation was equal to that of theseason’s rainfall. Supplemental irrigation that increased the totalwater supply by 20 percent almost doubled root yields.O
Overview ix5. Crop nutritionCombining ecosystem processes and judicious use of mineralfertilizer forms the basis of a sustainable crop nutritionsystem that produces more while using fewer external inputs.lthough cassava produces reasonable yields on poor soils,many varieties perform better with fertilization. Yields inAfrica, especially, could be markedly improved if farmers hadaccess to mineral fertilizer at a reasonable price. Farmers canimprove soil fertility with other “Save and Grow” measures.Intercropping grain legumes, and mulching the residues oflegumes and native weeds, boosts root yields. When combinedwith fertilizer, both alley cropping with deep-rooting leguminoustrees and the use of organic compost or farmyard manure producehigher crop yields and net incomes. Options to reduce the loss ofsoil nutrients to erosion include zero tillage, which maintains soilaggregate stability and internal drainage, contour hedgerows ofvetiver grass, and the application of mineral fertilizer, which leadsto faster soil coverage by the plant canopy.A6. Pests and diseasesProtecting cassava with pesticide is usually ineffective andhardly ever economic. A range of non-chemical measures canhelp farmers reduce losses while protecting the agro-ecosystem.rowers should use planting material of varieties withtolerance or resistance to major pests and diseases, as wellas ecosystem-based practices, such as mulching, maintaining soilorganic matter, and planting intercrops to provide a habitat forpest predators. Biopesticides, sticky traps and soapy water can helpcontrol many insect pests. Plant health strategies should encouragenatural biological agents – the mass release of a tiny wasp defeatedserious outbreaks of cassava mealybug in Africa and Asia. Toprevent weeds overwhelming young plants, farmers should useoptimum planting densities and fertilization, and varieties withvigorous early growth. Regular hand weeding can be as effective asweed control with herbicides. Farmers need to exercise care in thechoice of the herbicides and should follow the advice of local plantprotection specialists.G
x Save and Grow: Cassava7. Harvest, post-harvest and value additionFood for the household, feed for livestock, and raw materialfor a wide array of value-added products, from coarse flour tohigh-tech starch gels – cassava is a truly multipurpose crop.arvested cassava roots are consumed directly by many farmhouseholds or fed to their livestock. Roots can be processedinto granulated flour, or into high quality cassava flour which canbe used as a substitute for some of the wheat flour in bread andconfectionary. In Thailand and China, root starch goes into foodproducts, plywood, paper and textiles, and is used as feedstock forproduction of sweeteners, fructose, alcohol and fuel ethanol. Tworecent cassava mutations have starch properties that are highlyvalued by industry. The root is not the only useful part of the plant– young cassava leaves make a nutritious vegetable, and plant topscan be fed to cattle, buffaloes, pigs, chickens and silkworms.H8. The way forwardGovernments need to encourage smallholders’ participationin a sustainable cassava development agenda, and supportresearch and extension approaches that “let farmers decide”.armer participatory research and farmer field schools haveproven very effective in promoting sustainable naturalresources management in smallholder production systems.Cassava growers may also require incentives, such as paymentsfor environmental services, to adopt improved farming practices.Action is needed to make mineral fertilizer and other inputs moreaffordable to smallholders, and to provide them with quality,disease-free planting material. Investment in roads, storage andprocessing capacity in production zones will help cassava growersretain a bigger share of value-addition. Policies should promoteprivate investment in cassava processing, and foster associationsthat link producers with processors, promote standards andshare market information. While government subsidies mayreduce farmers’ exposure to price volatility, more sustainableoptions are available, such as crop insurance and supply contractsbetween food manufacturers and farmers’ cooperatives.F
Chapter 1Cassava,a 21st century cropThe “food of the poor” has becomea multipurpose crop that respondsto the priorities of developing countries,to trends in the global economy,and to the challenge of climate change.
Chapter 1: Cassava, a 21st century crop 3Cassava (Manihot esculenta Crantz) is one of some 100 speciesof trees, shrubs and herbs of the genus Manihot, which isdistributed from northern Argentina to the southern UnitedStates of America. While some studies indicate that cassavahas multiple centres of origin, others suggest that the cultivatedspecies originated on the southern edge of the Brazilian Amazon1-4.Botanically, cassava is a woody perennial shrub, which grows from1 m to 5 m in height. It is believed to have been cultivated, mainly forits starchy roots, for 9 000 years, making it one of agriculture’s oldestcrops. In pre-Colombian times, it was grown in many parts of SouthAmerica, Mesoamerica and the Caribbean islands.Following the Spanish and Portuguese conquests, cassava was takenfrom Brazil to the Atlantic coast of Africa. By the 1800s it was beinggrown along Africa’s east coast and in Southern Asia. Farming ofcassava expanded considerably in the 20th century, when it emergedas an important food crop across sub-Saharan Africa and in India,Indonesia and the Philippines.Since it is sensitive to frost andhas a growing season of nearlyone year, cassava is cultivatedalmost exclusively in tropical andsubtropical regions. It is growntoday by millions of small-scalefarmers in more than 100 countries, from American Samoa toZambia, under a variety of localnames: mandioca in Brazil, yucain Honduras, ketela pohon inIndonesia, mihogo in Kenya, akpuin Nigeria and sắn in Viet Nam.Manihot esculenta has characteristics that make it highly attractiveto smallholder farmers in isolated areas where soils are poor and rainfall is low or unpredictable. Since it is propagated from stem cuttings,planting material is low-cost and readily available. The plant is highlytolerant to acid soils, and has formed a symbiotic association with soilfungi that help its roots absorb phosphorus and micronutrients. Todiscourage herbivores, its leaves produce two glycosides which, whendigested, produce highly toxic hydrogen cyanide. Since most of the soilnutrients absorbed during growth remain in the above-ground partStudies suggest thatcassava was firstcultivated, as many as9 000 years ago, on thesouthern edge of theBrazilian Amazon, whereit is still grown today
4 Save and Grow: Cassavaof the plant, recycling the plant tops helps to maintain soil fertility.Under drought stress, leaf production is reduced until the next rains.Thanks to its efficient use of water and soil nutrients, and toleranceto sporadic pest attacks, cassava growers, using few if any inputs, canexpect reasonable harvests where other crops would fail.Cassava roots are more than 60 percent water. However, their drymatter is very rich in carbohydrates, amounting to about 250 to 300 kgfor every tonne of fresh roots. When the root is used as food, the besttime to harvest is at about 8 to 10 months after planting; a longergrowing period generally produces a higher starch yield. However,harvesting of some varieties can be “as needed”, at any time betweensix months and two years. Those attributes have made cassava oneof the world’s most reliable food security crops.Thanks to its roots’ high starch content, cassava is a rich sourceof dietary energy. Its energy yield per hectare is
Chapter 1: stCassava, a 21 century crop 1 Chapter 2: Farming systems 19 Chapter 3: Varieties and planting material 35 Chapter 4: Water management 49 Chapter 5: Crop nutrition 59 Chapter 6: Pests and diseases 73 Chapter 7: Harvest, post-harvest and value addition 87 Chapter 8: The way forward 97 Annex tables 109 References 121 Abbreviations 129
by upgrading value chains for new cassava products such as High Quality Cassava Flour (HQCF). This report revisits the value chains for cassava and cassava products in Tanzania and aims to develop new ideas for future interventions based on an up to date picture of the key and emerging demand drivers.
fermented food in Africa, showing some aspects of these foods. This review aim then to establish relationship between cassava main fermented food in Africa and their associate microorganisms properties, the nutritional function, safety values and health benefits for human nutrition. Main cassava fermented food technology in Africa
and the national household surveys in terms of reported cassava production and yields further underscore the need for methodological research for improving the statistics on root, tuber and tree crops in general, and cassava in particular. Considering the importance of cassava for food security and the absence of best practices in
1Faculty of Food Science and Nutrition, University Malaysia Sabah, Malaysia 2 Japan International Research Center for Agricultural Sciences, Tsukuba 305-8686 Japan Email: 1jsmsulthan@gmail.com, 2krachaai@ybb.ne.jp ABSTRACT Modified cassava starch (MCS) is a product derived from cassava chips that uses a principle of modifying
and job creation on a global perspective. Using cassava as model crop, we highlight some of the possible causes of agricultural mechanisation stagnation in the African region. 1.1. Cassava cultivation and mechanisation Cassava (Manihot esculenta Crantz) is grown all over the world and in Africa is the most produced ahead of sugar cane and maize .
non-fermented cassava flour. It focuses on quality assurance of the raw materials, processing, hygiene, storage and transportation, packaging and labeling. The manual outlines the operational steps or procedures that should be followed in the manufacture of safe and good quality cassava flour.
For consumptive purposes, cassava requires more processing than all the tuber crops. Amongst the root and tuber crops, cassava is the most perishable crop with two to three days of deterioration after harvest, and for it to be consumable, the cyanide content must be reduced to an acceptable and safe level.
yellow flecks to extensive areas of dark brown dry rot and become more severe as the plant ages. Cassava brown streak disease symptoms in roots of the susceptible variety, TME 204 (Namulonge, Uganda). Root constrictions and malformation are a common feature of severe CBSD. Cassava brown streak disease leaf symptoms in TME 14 (Namulonge, Uganda).
