African farmers facing climate change could look to cassava as best bet, as long-neglected root becomes more productive in hotter temperatures, scientists say; cassava eaten by nearly 500 million people each day
February 27, 2012
– Calling cassava "the Rambo of food crops," scientists Monday said the long-neglected root becomes even more productive in hotter temperatures and could be the best bet for African farmers threatened by climate change.
Cassava is the second most important source of carbohydrate in sub-Saharan African, after maize, and is eaten by around 500 million people every day, scientists said.
The root outperformed potatoes, maize, beans, bananas, millet and sorghum in tests using a combination of 24 climate prediction and crop suitability models, said scientists from the Colombia-based International Center for Tropical Agriculture and the center's Climate Change Agriculture and Food Security Research Program. Their findings were published Monday in a special edition of the scientific journal Tropical Plant Biology.
"Cassava is a survivor; it's like the Rambo of the food crops," said climate scientist Andy Jarvis, the report's lead author. "It deals with almost anything the climate throws at it. It thrives in high temperatures, and if drought hits it simply shuts down until the rains come again. There's no other staple out there with this level of toughness."
Cassava grows in poor soils and with little water.
By 2030, temperature rises of between 1.2 and 2 degrees Celsius combined with changes in rainfall patterns "will leave cassava in a class of its own," the study said.
In East Africa, for example, cassava production would increase 10 percent. In West Africa, where it is most widely eaten, cassava will hold its ground, significantly outperforming the suitability of potatoes which will decrease by 15 percent, beans at a decrease of 20 percent and bananas at a decrease of 13 percent.
In the cooler climes of southern Africa, climate change should bring a 5 percent increase in suitability for cassava, the scientists found. Only in Central Africa did it register a small, 1 percent decrease in suitability, according to the tests.
Jarvis said farmers could enhance nutrition and reduce risk from climate change by planting a diversity of crops, with cassava acting as a failsafe.
Cassava originated in South America, where it's called yucca and has been used since prehistoric time. It was introduced to Africa by Portuguese traders in the 17th century. It's eaten like a potato, boiled or fried, and often is pounded to a flour to make a thick porridge.
The scientists hoped their findings would push the scientific community to focus on the root. Cassava research has been dwarfed over the decades by greater research into better-known staples like maize, rice and wheat.
Breeding to improve drought and cold tolerance could support the expansion of cassava production into drier areas of sub-Saharan Africa and cooler parts of Southern Africa, the report said.
More research could also help make cassava more resilient to pests and diseases such as whitefly, mealybug, cassava brown-streak disease and cassava mosaic disease.
"Tackling cassava's vulnerability to pests and diseases could be the final hurdle to a food secure future for millions of people," continued Jarvis. "If we're well prepared for these threats, cassava could be one of the most climate change-resilient crops an African farmer can plant."
He was glad to finally be able to report some good news about food security and climate change in sub-Saharan Africa.
"While the other staples will struggle in the face of climate change, it looks as though cassava is going to thoroughly enjoy it."
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