London — Cassava is likely to outperform other crops amid rising temperatures in sub-Saharan Africa, and could even become more productive, offering farmers a way to cope with change climate change, says a new scientific study.
Using 24 climate and crop models, researchers found the hardy root crop – a major staple food for more than 500 million Africans – is expected to grow better by 2030 in nearly all parts of sub-Saharan Africa if the region sees temperature increases of between 1.2 and 2 degrees Celsius and accompanying shifts in rainfall patterns.
“Cassava is a survivor; it’s like the Rambo of the food crops,” said the report’s lead author, Andy Jarvis, a climate scientist with the Colombia-based International Center for Tropical Agriculture (CIAT).
“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,” he added in a statement.
Jarvis said farmers ideally should plant a diversity of crops, with cassava acting as a “failsafe” – a strategy that could improve nutrition and reduce climate risk.
A native of South America, cassava was first introduced to sub-Saharan Africa by Portuguese traders in the 17th century, and is now the second most important source of carbohydrates in the region. It can be boiled and eaten or used in soups and stews, and is often processed into flour or tapioca.
Scientists from CIAT and the Climate Change Agriculture and Food Security Research Programme (CCAFS) of the Consultative Group on International Agricultural Research (CGIAR), an international research consortium, compared the expected impacts of climate change on the production of cassava and six other key staple crops in sub-Saharan Africa – potato, maize, bean, bananas, millet and sorghum.
The main “climate suitability” model they used analyses the geography of crop suitability with regard to climate conditions and produces a rating that is related to agricultural yields, the paper notes.
According to the results, published this week in the journal Tropical Plant Biology, in East Africa cassava bucks the declining trend of all other crops in the study, with a 10 percent increase in climate suitability by 2030.
In West Africa, it is expected to hold its ground, significantly outperforming the suitability of potatoes (down 15 percent), beans (down 20 percent) and bananas (down 13 percent).
In southern Africa, cassava – together with bananas and maize – will see a 5 percent increase in suitability, the model suggests. Only Central Africa is forecast to see a decrease in cassava climate suitability of 1 percent – still better than the substantial declines expected for potatoes and beans.
CALL FOR MORE RESEARCH
Yet while cassava can produce its starch-rich roots in poor soils and with little water, investment in cassava research has been dwarfed by work on better-known staples like rice, wheat and maize, CIAT said.
The study highlights the importance of further research to make cassava more resilient to pests and disease outbreaks, including such problems 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,” Jarvis said. “If we’re well prepared for these threats, cassava could be one of the most climate-change-resilient crops an African farmer can plant.
Breeding new varieties to improve cassava’s tolerance to both drought and cold could also help expand production into drier areas of sub-Saharan Africa and cooler parts of southern Africa.
“We’ve been waiting a long time for some good news about food security and climate change in sub-Saharan Africa. Finally I think it’s arrived,” Jarvis said. “While the other staples will struggle in the face of climate change, it looks as though cassava is going to thoroughly enjoy it.”