Climate change is impacting all aspects of the planet, and our agricultural production is no different. The U.S. Environmental Protection Agency says agriculture is climate-sensitive and requires resources like land and water that are dealing with their own climate impacts. As a result, producers are working to adapt to changing conditions. A new study shows that apple producers may be among those who need to do so.

New research published in the journal Environmental Research Letters and conducted by a team at Washington State University looked at climate trends between 1979 and 2022 in areas with high apple production to see how much average conditions are changing. They focused on Yakima County in Washington State, Kent County in Michigan, and Wayne County in New York State, all of which were found to have significant trends toward fewer cold degree days, a higher number of warm fall nights, and more growing degree days, or days with temperatures above what’s needed for growth.

The researchers say their findings suggest adaptation strategies are needed to ensure continued production.

Deepti Singh, study co-author and climate scientist at Washington State University, says, “We shouldn’t take the delicious apples we love to consume for granted. Changing climate conditions over multiple parts of the growth cycle pose potentially compounding threats to the production and quality of apples. Moving forward, it would be helpful to think about adaptations at different stages of apple growth that can minimize overall harmful impacts.”

When it comes to potential impacts on apple growth, Yakima County was found to be especially ripe with them. The study looked at six different climate metrics that can impact apple production, growth, development, and quality, and Yakima County was found to have significant changes in five areas: Earlier last days of spring frost, fewer cold degree days, an increasing number of growing degree days, more extreme heat days, and a larger number of warm nights. The other factor studied, chill portions – or the number of colder hours needed for tree dormancy, was not found to be especially impacted.

The researchers say these changes can impact apple production due to a shorter dormancy period, different bloom timing, a higher risk of sunburn, and a more significant chance of poorer appearance and quality.

Though some apple producers are already trying mitigation strategies, including netting and evaporative cooling, the researchers say more adaptations may be needed. The team is currently working on a project, funded by a USDA grant, to help apple and pear producers mitigate the impacts of extreme climate events.

Kirti Rajagopalan, study co-author and biological systems engineer at Washington State University, says, “Washington is a great place to start to talk about adaptation. A lot of the commercial apple production happens in the northern U.S. There are also parts of Washington where the summers can get pretty hot, so this is a good place for a case study — and if we can manage it here, then it’s likely manageable elsewhere too.”

You can read the whole study here.