What will be the role
of cassava in a climate changed world?• We know cassava is a resistant crop….• …..but will it stand up to climate change?• How does it fair up with other major staples?• What are the research challenges over the coming decades?• What has all this got to do with film stars?
Cassava – an exception to
the rule? •For example, US maize, soy, cotton yields fall rapidly when exposed to temperatures >30˚C •In many cases, roughly 6-10% yield loss per degree Schlenker and Roberts 2009 PNAS
What will this mean for
cassava? Minimum absolute 300 rainfall (mm) Minimum optimum 800 rainfall (mm) Maximum optimum 2200 rainfall (mm) Maximum absolute 2800 rainfall (mm) Killing temperature (°C) 0 Minimum absolute 15.0 temperature (°C) Minimum optimumIt evaluates on monthly basis if there 22.0 temperature (°C)are adequate climatic conditions Maximum optimum 32.0 temperature (°C)within a growing season for Maximum absolutetemperature and precipitation… 45.0 temperature (°C)…and calculates the climatic suitability of the Growing season (days) 240resulting interaction between rainfall andtemperature…
Cassava’s role as a substitution
crop• Cassava as a fallback crop under an uncertain climate (risk management)• Cassava as the substitution crop for other staples more sensitive to heat and drought• Cassava as a source of increasing food and nutritional security across the continent
Future Priorities• The Achilles heal:
addressing pest and disease susceptibility• Breeding in low latitudes for cold tolerance (e.g. Southern Africa, Brazil, China)• Improving cassava science and knowledge: physiological models of the crop and its diseases
Look for conditions in future
analogues to existing conditions how cassava will performSimulate crop growth and development within andbeyond the current climate range where cassava is currently grown
It will be developed from
the Mathews & Hunt GUMCAS modelIt appears to be the most complete cassava model currentlyavailable and also it is in DSSAT requires more developmentand calibration• Improve the DSSAT GUMCAS model with (so far): • DSSAT team (Gerrit Hoogenboom (WSU), Cheryl Porter, K. Boote, and J. Jones (University of Florida)) • CLAYUCA and partners • The Thai cassava modeling group (Dept of Agriculture, Khon Kaen University and Chiang Mai University) • Researchers involved in developing the early cassava models (e.g. Tony Hunt, James Cock).
• Information of such aspects
as the effects of elevated CO2 levels on growth and development.• Trials by researchers valuable information for development and calibrate the model.• Information on a farm level realistic simulation of the crop considering yield gap• The creation of an inter-agency cassava model that evaluates a variety of scenarios with respect to cassava productivity• Members can use the models directly, or request specific analysis