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Redesigning Cassava for Tomorrow’s Demands
Global trends for world’s most important food crops
Change in 30 years, to 2009 (%)
Production Harvested area
Yield
Cassava 101 44 40Maize 95 29 52Rice 81 14 60Wheat 61 -1 63Millet 32 -5 39Potato 10 -5 12Barley -3 -35 48Sorghum -5 -1 -4Sweet potato -22 -27 6Oats -45 -60 37
Source: FAOSTAT 2012
.
• Low soil fertility• Drought-prone areas• Sloped lands• Low access to roads and markets• Product options limited in many areas
Typical Agro- and Market Environment for Cassava
But the crop also can respond to good management to produce very high yields
Cassava for modern times
Challenges• Uncertainties of climate change• Soil fertility maintenance and erosion control• Pest and disease management• Production systems for clean planting material• Trait development tailored to new markets
Opportunities• Resilience in multiple environments• Diverse new market options• Under-exploited genetic diversity
Is cassava the answer for climate change adaptation?
Based on the EcoCrop model: Cassava will respond positively in many current regions of planting
Ceballos et al. 2011Jarvis et al. in press
More than 6,000 accessions plus 1000 acessions of 30 wild species
The genebank:Our main source of genetic variability
Frequency of major cassava pests across continents
Pest category Americas Africa Asia Whiteflies 11 3 3Mealybugs 6 3 6Root mealybugs 2 2 0Mites 30 13 15Scale insects 8 7 3White grubs 6 3 5Termites 2 2 1Thrips 5 1 5Leafhoppers 3 0 0Grasshoppers 2 4 0Shootflies 3 0 0Stemborers 12 4 3Lacebugs 4 0 0Burrower bugs 3 0 0Hornworm 2 0 0Tiger moth 2 0 0Army worm 3 0 0Gall midge 1 0 0Dried cassava 5 6 6
Total 110 48 47
Challenges and risks of intensifying cassava production
Bacterial Blight in southern Brazil: results of poorly planned rapid scale-up
Low intensity, stable traditional production
Preparing for new challengesof biotic constraints
Climate change models suggest that the greatest impact on cassava will be from biotic constraints, and much less from abiotic (drought; higher temperatures)
A recent example of new pest introduction
Cassava Mealybug in Thailand, March 2010
Anagyrus lopezi
Identification and characterizationMonitoring of spread and impactTraining 14 Asian scientists
Implementation and validation of management strategiesKit development for on-farm detection
Asia: Cassava Witches’ broom
CIAT Roles1. RISK ASSESSMENT: Lead a global assessment of
threats from cassava pests2. SURVEILLANCE: Establish comprehensive
surveillance and monitoring with national and international partners
3. MANAGEMENT: Establish or strengthen core capacities to meet global pest management needs
4. CAPACITY BUILDING: sustainable capacity to respond to pest challenges
• Amylose-free (waxy): multiple food and industrial applications
• Small granule starch: rapid hydrolysis for ethanol industry
• High β-carotene: for Vitamin A deficit areas
• Forage varieties: adding an animal component into small-holder systems
Value-added traits for new markets
Source
Storage stability (4°C)
Freeze/thaw stability(18°C) Clarity Taste
Maize * * * CerealRice *** * * CerealPotato * * *** NoneCassava *** ** ** NoneWaxy maize *** ** ** CerealWaxy Rice *** *** * CerealWaxy Potato ** ** *** NoneWaxy Cassava *** *** *** None
• = low acceptability** = medium acceptability*** = high acceptability
Source: Sánchez T., Dufour D., Moreno I. X., Ceballos H. (2010). Comparison of Pasting and Gel Stabilities of Waxy and Normal Starches from Potato, Maize, and Rice with Those of a Novel Waxy Cassava Starch under Thermal, Chemical, and Mechanical Stress. Journal of agricultural and food chemistry, 58, 5093–5099. http://dx.doi.org/10.1021/jf1001606
Some characteristics of cassava starch important for the food industry
Introduction of an animal component into smallholder systems is one of the best ways to
improve household nutritional status
• Direct feeding of surplus root production• Feeding of leaves and young stems• Feeding of residues of processing (peels, fiber, starch
residues)
Progress in breeding for total carotenoids content (A nutritional goal of 15 µg/g established in 2005)
Progress in breeding for total carotenoids content (A nutritional goal of 15 µg/g established in 2005)
TCC
(µg/
g)
0
5
10
15
20
25
30
2005 2006 2007 2008 2009 2010
Minimum
Average
Maximum
Year
y = 2.346x + 8.6995R2 = 0.7763
Some current projects in molecular analysis
High b-Carotene Whitefly resistanceTolerance to post-harvest deterioration
Drought tolerance
Summary: Cassava’s Redesigno Transition from low-value commodity crop to diverse and higher level
value chainso Protect the crop from the current biotic threats trans-boundary movemento High yielding and high quality varietieso Management systems to reduce production costs (e.g. labor use)o Integrate molecular and traditional breeding approacheso Adapt to climate change (pests and diseases, practices to conserve soil
water)o Policies and systems that provide better income while protecting the
environment
Train a new generation of scientists!
Working together for a New Future for cassava
growers in Asia -- through a growing interdisciplinary team in Hanoi with close
linkages to CIAT-Colombia
CIAT: Science to Cultivate Change
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