Beans are a food staple for 400 million people in the developing world and have long been hailed as ‘the meat of the poor’ thanks to their high iron and protein content, according to researchers from CGIAR, a global research partnership which aims to improve global nutrition and ensure sustainable management of natural resources.
But climate experts have warned that bean crops will not withstand rising temperatures, and have predicted a 50% loss of bean-producing areas in eastern and central Africa by 2050.
Therefore, CGIAR scientists began crossing common bean types with hardier ones and have produced heat-resistant hybrids.
Andy Jarvis, a CGIAR climate change expert said: "As a result of this breakthrough, beans need not be the casualty of global warming that they seemed destined to be, but rather can offer a climate-friendly option for farmers struggling to cope with rising temperatures."
The CGIAR database: Full of beans
Many of the heat tolerant beans are crosses between the ‘common bean’ – including pinto, black, white and kidney beans – and the tepary bean, a hardy strain that has been cultivated since pre-Colombian times in the arid climate of northern Mexico and south-west USA.
The researchers searched CGIAR’s gene bank database – which contains nearly 750,000 samples of cereals, legumes and other important food crops – to identify genomic traits that were tolerant to extreme weather conditions, such as heat, flood and drought as well as certain pests.
CGIAR executive James Wadsworth called these genebanks a “front-line defence to climate change”.
"The development of these heat-defying beans also highlights what can be achieved when we invest in modern science to find solutions to urgent challenges, with expected economic benefits vastly exceeding the costs of investment in the research," he said.
Already producing higher yields
The researchers tested their beans in greenhouses in Colombia, adjusting the night-time temperatures to see how much heat the beans could withstand.
Beebe said: "We confirmed that 30 heat-tolerant lines are productive even with night-time temperatures above 22 degrees Celsius. Normally, bean yields start to falter when the temperatures exceed 18 or 19 degrees Celsius."
One of the bean varieties developed by CGIAR scientists has already been introduced into the commercial food chain in Nicaragua. When tested in Costa Rica it yielded twice as many beans as other varieties cultivated by farmers there.
This showed there was an immediate need for the resistant beans, Beebe said.
"Heat may already be hurting bean production in Central America far more than we thought and farmers could benefit from adopting the new heat-beater beans right now."
CGIAR identified the most vulnerable areas - where bean production was likely to be seriously disrupted by rising temperatures - as Nicaragua, Haiti, Brazil, and Honduras, and Malawi and the Democratic Republic of the Congo in Africa.
The scientists say they have also been breeding high-iron varieties to tackle malnutrition in developing countries where half of children are iron deficient.
The full report Developing beans that can beat the heat can be read here .