As a result of a major breakthrough, beans – once
feared to be a casualty of climate change – are now set to withstand
extreme temperatures, protecting a staple food of the poor in developing
countries.
Amidst fears that global warming could zap a vital source of protein that has sustained humans for centuries, CGIAR bean breeders
announced today the discovery of 30 new types, or lines as plant
breeders refer to them, of “heat-beater” beans that could keep
production from crashing in large swaths of bean-dependent Latin America
and Africa.
“This discovery could be a big boon for bean production because we
are facing a dire situation where, by 2050, global warming could reduce
areas suitable for growing beans by 50 percent,” said Steve Beebe, a
senior CGIAR bean researcher.
“Incredibly, the heat-tolerant beans we tested may be able to handle a
worst-case scenario where the build-up of greenhouse gases causes the
world to heat up by an average of 4 degrees Celsius (about 7.2 degrees
Fahrenheit),” he said. “Even if they can only handle a 3 degree rise,
that would still limit the bean production area lost to climate change
to about five percent. And farmers could potentially make up for that by
using these beans to expand their production of the crop in countries
like Nicaragua and Malawi, where beans are essential to survival.”
CGIAR researchers had previously warned that rising temperatures were
likely to disrupt bean production in Nicaragua, Haiti, Brazil, and
Honduras, while in Africa, those warnings had focused on Malawi and the
Democratic Republic of the Congo as the most vulnerable, followed by
Tanzania, Uganda, and Kenya.
“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,” said Andy Jarvis, a CGIAR climate change expert.
Many of the new heat-tolerant beans developed by the CGIAR scientists
are “crosses” between the “common bean”—which includes pinto, white,
black, and kidney beans—and the tepary bean, a hardy survivor cultivated
since pre-Columbian times in an area that is now part of northern
Mexico and the American southwest.
Often called the “meat of the poor” for the affordable protein it
provides, the crop is a vital foundation of food security for more than
400 million people in the developing world. Beans are a highly
nutritious food, offering protein, fiber, complex carbohydrates,
vitamins and other micronutrients. In addition to heat tolerance, CGIAR
experts are simultaneously breeding for higher iron content to enhance
the beans’ nutritional value.
Unlocking the Potential of Humanity’s Key Crops...
The new beans are a landmark result of urgent efforts by CGIAR to
develop new crop varieties that can thrive in drastic weather extremes.
The bedrock of this research is CGIAR’s “genebanks”,
which preserve the world’s largest seed collections of humanity’s most
important staple crops. Using new genomic tools, plant breeders are now
better able to unlock the potential of the genebanks’ vast genetic
diversity by probing nearly 750,000 samples of cereals, legumes, roots
and tubers, trees, and other important food crops—along with their wild
relatives—to identify genes with traits like heat, flood, and drought
tolerance or resistance to pests and disease that can help farmers adapt
to environmental stresses.
“The payoff we are seeing from these bean breeding efforts
underscores the vital importance of investing in CGIAR’s genebanks—a
front-line defense in the race to adapt crops to climate change to
protect the staple food supplies of poor farmers and consumers and avert
food crises around the world,” said Jonathan Wadsworth, Executive
Secretary of the CGIAR Fund Council.
“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.”
The heat beaters emerged from the methodical and exhaustive testing
of more than 1,000 bean lines, work that originally started as an effort
to develop beans that could tolerate poor soils and drought. The focus
turned to heat-tolerance following an alarming 2012 report from CGIAR
scientists warning that heat was a much bigger threat to bean production
than previously believed.
Led by CGIAR researchers, a team of the world’s leading bean experts
quickly moved to cultivate test plots on Colombia’s Caribbean coast,
where they deliberately exposed beans to night-time temperatures well
above what they can normally tolerate. Scientists also established
greenhouses so that temperatures could be dialed up on demand.
“We confirmed that 30 heat-tolerant lines are productive even with
night-time temperatures above 22 degrees Celsius (about 72 degrees
Fahrenheit),” Beebe said. “Normally, bean yields start to falter when
the temperatures exceed 18 or 19 degrees Celsius (about 64 to 66 degrees
Fahrenheit).”
Among the beans found to be especially heat tolerant was one that was
recently introduced into commercial production in Nicaragua, chiefly
because of its performance in drought conditions. Tested in dry
conditions in Costa Rica, it yielded more than twice the amount of beans
compared to what farmers were currently cultivating. Beebe said
scientists now have evidence that the superior performance was due not
just to drought tolerance but also heat tolerance.
“What this shows us is that 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,” he said.
Better Beans for Better Nutrition
To provide a sustainable and cost-effective way to combat hidden
hunger, caused by diets low in key vitamins and minerals, CGIAR
researchers embarked more than a decade ago on a pioneering program to improve the nutritional content of staple food crops that the poor rely upon.
Some of the heat-tolerant beans identified by Beebe and his team have
also been deliberately bred through conventional methods to be higher
in iron in an effort to tackle malnutrition. In developing countries,
deficiencies of this essential micronutrient afflict one out of every
two preschool children and pregnant women, making them highly
susceptible to anemia and compromising children’s growth and cognitive
development. While beans are already high in iron, these new varieties
could eventually provide up to 60 percent of daily iron needs for women
and children—almost twice the iron of non-improved beans.
“A couple of years ago, when climate change experts warned that
rising temperatures could be devastating for bean production, we were
asked how this would affect high-iron beans,” said Beebe. “Now, I am
confident that we can confront this challenge as well. We can develop
more iron-rich beans that are also heat tolerant. These beans would
deliver even greater benefits than expected because they could be grown
more widely.”
