Past and future changes in potato production vulnerabilities in Maine, USA

Authors: Han, Eun Jin; INES, AMOR - Pepsico; Fleisher, David

Submitted to: Climatic Change
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/12/2025
Publication Date: 7/10/2025
Citation: Han, E., Ines, A.V., Fleisher, D.H. 2025. Past and future changes in potato production vulnerabilities in Maine, USA. Climatic Change. https://doi.org/10.1007/s10584-025-03977-6.
DOI: https://doi.org/10.1007/s10584-025-03977-6

Interpretive Summary: Maine's favorable climate for potato growth has been threatened by the changing climate. A recent drought led to the lowest Maine potato yields in over two decades, profoundly impacting local growers. This study analyzed historical weather trends affecting potatoes: minimum and maximum temperatures, dry spells, heatwaves, and temperature thresholds for tuber quality. A crop model was used to translate climate data into practical information on irrigation and adaptation for growers. Results confirmed that temperatures are rising, especially nighttime and heatwave duration, in Aroostook County, Maine’s potato heartland. These changes make it riskier to grow potatoes without adaptations. Maintaining today’s current yields now requires more irrigation than in the past. Future climate scenarios project more heat-stressed days and sub-optimal temperatures. Growers can potentially shift to earlier planting dates and use more irrigation to maintain production. Developing long-term water management strategies and improving water use efficiency are crucial for mitigating future vulnerabilities in Maine's potato industry. This information is helpful for farmers, extension agents, policy makers, and scientists who have an interest in safe, secure, and affordable crop production.

Technical Abstract: Maine's favorable climate for potato growth has been threatened by the changing climate as an unprecedented drought in 2020 resulted in a significant reduction in yield. This study investigated climate-induced vulnerabilities by conducting trend analysis for weather indices affecting potato growth, including daily minimum (Tmin) and maximum temperature (Tmax), length of dry spells, heatwave duration, several temperature thresholds critical to tuber quality, and tuber initiation. A crop simulation model was used to translate the climate/weather data into more practical information for growers' decision-making and climate change adaptation associated with irrigation water requirement and water use efficiency. This study confirmed the occurrence of increasing trends in the historical temperature record, particularly nighttime temperatures and heat wave duration, especially in Aroostook County, Maine's potato heartland. The increasing temperature was associated with higher probability of exceeding optimal temperature ranges, in excess of 20°C, for potato tuber growth. To maintain current yields, growers will need to use more water for irrigation. Increasing temperatures make potatoes less water-efficient, offsetting the benefits of CO2 fertilization. Future climate change scenarios revealed that potatoes will experience more heat-stressed days (Tmax > 32°C) and stretches of sub-optimal temperatures by mid-century. Possible planting dates will shift 2-9 days earlier compared to historical averages. The irrigation water requirements will increase by up to 19% in the mid-century to meet potential potato production in the future. These results indicate that developing long-term strategies for managing agricultural water resources and improving water use efficiency are crucial to mitigating future vulnerabilities in Maine's potato industry.