At a research center northwest of Beijing, molecular biologist Li Jieping and his team harvest a cluster of seven unusually small potatoes, including one as small as a quail egg, from a potted plant.
Grown in conditions that simulate predictions of higher temperatures at the end of the century, potatoes pose a worrying sign of future food security.
At just 136 grams, the tubers weigh less than half that of a typical potato in China, where the most popular varieties are often twice the size of a baseball.
China is the world’s largest producer of potatoes, which are critical to global food security due to their high yield compared to other staple crops.
But they are particularly vulnerable to heat, and climate change, driven by fossil fuel emissions, is pushing temperatures to dangerous new heights while worsening droughts and floods.
Faced with an urgent need to protect food supplies, Li, a researcher at the International Potato Center (CIP) in Beijing, is leading a three-year study into the effects of higher temperatures on the vegetable. His team focuses on the two most common varieties in China.
“I worry about what will happen in the future,” Li said. “Farmers will harvest fewer potato tubers, which will influence food security.”
Li’s team grew their crop for three months in a walk-in chamber set at 3 degrees Celsius above the current average temperature in northern Hebei and Inner Mongolia, the highest altitude provinces where Potatoes are usually grown in China.
Their research, published in the journal CSmart Agriculture This month, higher temperatures accelerated tuber growth by 10 days, but reduced potato yields by more than half.
Under current climate policies, the world will face warming of up to 3.1°C above pre-industrial levels by 2100, according to a United Nations report released in October.
Chinese farmers say they are already feeling the effects of extreme weather events.
In Inner Mongolia, dozens of workers, white sacks in hand, rush to collect potatoes torn from the ground before the next downpour.
“The biggest challenge for potatoes this year is the heavy rains,” said manager Wang Shiyi. “This caused various diseases…and significantly slowed down the progress of the harvest.”
Meanwhile, seed potato producer Yakeshi Senfeng Potato Industry Company has invested in aeroponic systems where plants are grown in the air under controlled conditions.
Farmers are increasingly demanding higher-yielding potato varieties that are less susceptible to disease, particularly late blight, which caused the Irish potato famine in the mid-19th century, and which thrive in hot and humid conditions.
“New, more aggressive strains (mildew) have begun to emerge, and they are more resistant to traditional prevention and control methods,” said general manager Li Xuemin, explaining the strategy of the Inner Mongolia-based company.
The research by CIP, headquartered in Lima, is part of a collaborative effort with the Chinese government to help farmers adapt to hotter and wetter conditions.
In the greenhouse outside Li’s lab, workers dab pollen from white potato flowers to develop heat-tolerant varieties.
Li says Chinese farmers will need to make changes over the next decade, planting in spring rather than early summer, or moving to even higher altitudes to escape the heat.
“Farmers need to start preparing for climate change,” Li said. “If we don’t find a solution, they will make less money from falling yields and the price of potatoes could rise. ”
