Climate change may reduce frost damage to orchard crops

CalAgroClimate web tools help farmers prepare for frost events

A cold snap damaged almond blossoms across the Central Valley, resulting in more than $44 million in crop insurance claimsin late February 2018. A multi-day frost event wiped out roughly 75% of California's citrus crop and severely damaged avocados in January 2007. Frost can damage crops, impact growers' bottom lines and drive up food prices for consumers. With advance notice, farmers may be able to use heaters, wind machines, irrigation and other tactics to lessen some of the impacts of cold weather, such as damaging near-ripe citrus fruit or killing the bloom in almonds.  

CalAgroClimate is a new farmer-focused website that can help growers anticipate weather-related risks and make plans for taking defensive action. Growers and crop consultants can use CalAgroClimate's crop and location-specific tools and resources to help prepare for upcoming frost events. The website's tools can also support on-farm decisions for managing heat, crop development and pests. 

Future holds less frost

The risk of frost damage to crops and the need to prepare for that risk is top-of-mind for many farmers today, but will it always be so? To examine what climate change might mean for future frost risk, researchers at UC Davis, UC ANR and the USDA California Climate Hub conducted a study examining the incidence of temperatures below multiple “frost thresholds” during the months of critical development phases for three frost-sensitive California crops: almonds, avocados and navel oranges.

The researchers found that even during the coldest winters and springs, the incidence of frost exposure declined under projected mid-21st century climate conditions by more than 50% for almonds and oranges, and by more than 75% for avocados. While farmers in 2050 will not find frost risk to completely be a worry of climates past, they will not have to contend with the same frost concerns that farmers face today.

Beyond the obvious benefits of reduced risk of crop damages, additional benefits of reduced frost exposure include lower water use and energy costs associated with mitigation actions. Irrigation is a primary means of protecting crops from frost temperatures, and with fewer hours below freezing that means fewer hours of running water and using pumps. The authors of the future frost exposure study showed that growers may collectively save tens of thousands of acre feet of water and enjoy millions of dollars in energy savings.

Few aspects of climate change are considered “positives,” and although the warming winters and springs that result in reduced frost temperatures could also come with increased pest pressure, reduced chill accumulation and other challenges, the reduction in frost exposure is a silver lining.

However, until this frost-free future arrives, growers still need to be prepared to protect their orchards from frost. To assess frost risk for the next seven days for your location, check out the new interactive Frost Advisory Tool at CalAgroClimate.org.

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