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Julian R - Is cassava the answer to African climate change adaptation Mar 2013
1. Is cassava the answer to African
climate change adaptation?
Julian Ramirez-Villegas
Andy Jarvis, Beatriz Herrera and Carlos Navarro
2. Why cassava?: a main staple in Africa
• Contributed ~84 kcal/capita/day in 2007 (globally)
• In Africa, however, it was 154 kcal/capita/day (387
wheat, 359 for maize, 205 rice)
• Africa: ~124.3 million Ton produced in 2010 (52%
of total)
FAOSTAT (2012)
3. Crop hardiness: reported
physiological responses
• Adapted to warm and moist areas, but can
deal with dryness
Pn (umol CO2 per m2/s)
El-Sharkawy (2006)
El-Sharkawy and Cock (1986)
4. Some limiting factors
• Pests and diseases
Herrera et al. (2011)
• Low input farming systems, thus large yield
gaps
Licker et al. (2010)
6. “In 2002, cassava was considered
an ‘orphan crop’, neglected by
both investors and practitioners of
agricultural research”
Fauquet et al. (2012)
7. Potential for climate change adaptation
• No systematic approach
to quantify the potential
of cassava
• Lobell et al. (2008) report
increases of +1.1 %
(average)
• Liu et al. (2008) report
little impacts on cassava
yield (-2 to 1 %)
8. Approach
• Use a simple suitability model to quantify the
response of the crop by 2030s (SRES-A1B)
• Uncertainty in projected climate quantified
through the use of multiple (24) GCMs
• Compare with other staples in the region
(maize, beans, sorghum, banana, millet,
potato)
• Benefits of further crop improvement
• Assess the impacts on pests and diseases
9. The EcoCrop model
…uses parameterised thresholds to determine
climatic suitability of a particular environment…
Ramirez-Villegas et al. 2013 Agr. For. Met. 170: 67-78
13. In addition to large CO2
stimulation
Rosenthal et al. (2012)
report ~100 %
increases in root yield
under elevated CO2
Under optimal management
Further evidence of the crop’s potential under
climate change
14. But more work is needed on pests
and diseases
Potentially
less pressure
15. In 2012, our article empowered CIAT to play a major
role in the Global Cassava Partnership 21st Century,
now receiving funds from the Gates Foundation.
16. Conclusions
• Cassava consistently outperforming
other staples in SSA under climate
change
• Stress-tolerant cassava for managing
risk
• And also for transformational
adaptation (transition systems)
• Crop improvement to further increase
biotic stress resistance