Potatoes for a warming world

Potatoes. Most of us don’t think about them much, but globally, they are an important food source. Together with cassava, potatoes are right behind rice, corn (maize), and wheat, with regard to the amount of calories supplied to the world’s population.¹ Potatoes also use land efficiently, yielding about 3½ times more calories per hectare than corn or rice, and 8 times that of wheat or soybeans.²

Climate change warming presents a looming challenge to potato production, because potatoes, which are native to the cool highlands of the Bolivian-Peruvian Andes mountains, do best in cool climates. Potato tubers don’t grow well when daytime temperatures are above 27° C (80° F). ³

All plants, including potatoes, have a heightened adverse photosynthesis response to heat, and start to react with oxygen instead of CO₂. The reaction produces a toxic byproduct (glycolate), that the plant has to expend energy to eliminate. While plants are doing that, they are not using the CO₂ to grow bigger.⁴ With potatoes, that means smaller tubers in hot weather.

Researchers from a number of universities have identified a couple of genes that work to eliminate glycolate in potato plants. They have bred some potato plants that have a heightened elimination response to heat. Over three years of field trials, the researchers found that the modified plants did better during heat waves (3 episodes that exceeded 35° C (95° F) during one trial season), and overall produced 30% more tuber weight than unmodified control plants.

In an ideal world, we would have acted decades ago so that we wouldn’t need different potatoes. Since we didn’t, and climate change warming is happening, it is good that there are people developing innovations like climate-adapted potatoes, which will help to mitigate some of the worst consequences.

Reading

1. WorldAtlas. “What Are the World’s Most Important Staple Foods?,” June 7, 2019. https://www.worldatlas.com/articles/most-important-staple-foods-in-the-world.html.
2. “Feeding the World - Spudman.” Accessed April 12, 2025. https://spudman.com/article/feeding-the-world/.
3. Joes, Bryan. “What Temperature To Grow Potatoes - GardenerBible,” December 14, 2024. https://gardenerbible.com/what-temperature-to-grow-potatoes/.
4. Meacham-Hensold, Katherine, Amanda P. Cavanagh, Peyton Sorensen, Paul F. South, Jessica Fowler, Ryan Boyd, Jooyeon Jeong, et al. “Shortcutting Photorespiration Protects Potato Photosynthesis and Tuber Yield Against Heatwave Stress.” Global Change Biology 30, no. 12 (2024): e17595. https://doi.org/10.1111/gcb.17595.