ISSN 2027-1238
E-Newsletter No. 5
October 2009

Cassava could be about to experience something of a heyday. With climate change expected to take its toll on staples like rice, wheat, and maize, the potential of cassava—notoriously hardy when the going gets tough—is growing by the day.

CIAT climate change models show that by 2050 almost one-fifth of cassava-growing land is expected to benefit from rising temperatures and changes in rainfall. While this is good news for one of the world's most important sources of carbohydrate, improving cassava varieties to become even more resilient could result in an additional 60 million hectares of new land becoming suitable for cassava production.

Grown across the tropics for its energy-packed tuberous roots, cassava is of particular value to smallholders due to its remarkable ability to tolerate drought-like conditions and thrive in poor soils. While it is predominantly grown as a food crop in Africa and Latin America, cassava starch processing is a major employer, and Asia is a world leader in the industrial production of the crop.

In order to protect both food and livelihoods, improved cassava varieties that capitalize on the crop's inherent resilience could become the cornerstone of climate change adaptation. This is particularly true of Latin America—the ancestral home of cassava—that has much to gain from improved varieties. While some parts of the region are likely to see increases in cassava suitability, the models show large areas where suitability falls. It is in these frontiers where improved cassava could have the greatest impact.

According to climate change expert Andy Jarvis of CIAT's Decision and Policy Analysis Program, developing cassava lines with improved tolerance to both heat and cold, and greater resistance to drought and flooding is essential.

"The message coming out of the modeling is that there is no single trait that provides global gains for cassava. Instead, breeding must tackle multiple constraints," said Jarvis. If this happens, then by 2050 these new technologies could benefit one-third of current cassava fields in Latin America, and nearly triple the area suitable for cassava production. But there is one catch: there is no time to lose.

"The scientific community makes these decisions now," urged Jarvis. "It takes a minimum of a decade from beginning work on crop improvement to getting the new variety in farmers' fields, so we need to be looking closely at what the models are telling us about the future challenges, and tailoring our research to match. With the right science and the right priorities, cassava could become a super-crop, but we have to move now."

Jarvis also stressed the importance of research-and-development networks, such as Clayuca (Latin American and Caribbean Consortium to Support Cassava Research and Development) for ensuring new technologies reach farmers quickly. The CIAT-coordinated network, which recently celebrated its 10th anniversary, has members from the public and private sectors in 16 countries, all working to improve the generation, and exchange of new cassava-related technologies. The initiative has been responsible for the development, adaptation, and transfer of several "technological platforms" for cassava production, processing, and utilization that are helping farmers increase yields and improve livelihoods.

"Collaboration and dissemination are essential for climate change adaptation," continued Jarvis. "Networks like Clayuca are vastly improving the impact of cassava research; they enable high-speed links between the laboratories and farmers' fields."

Uncertainties remain about the impact of climate change on cassava's susceptibility to pests and diseases, and therefore the extent to which increases in land planted to the crop will correspond to increases in yields. While Jarvis recognizes the limitations of the climate models, he is also assured of the need for action.

"There's simply no time to wait-and-see," he continued. "By combining the right research now, with the right partnerships and the right methods for dissemination, cassava can fulfill its potential as a crop capable of thriving in the face of climate change.

Contacts:
Andy Jarvis, a.jarvis@cgiar.org
Bernardo Ospina, b.ospina@cgiar.org