Extreme heat effects on perennial crops and strategies for sustaining future production.

• This literature review highlights the effects of extreme heat exposure on perennial agriculture. • California crop production will be impacted by climate change and heat extremes. • Both cool- and warm-season heat extremes will influence crop development, yield, and quality. • Current extreme heat adaptation practices may not be sustainable under future climatic conditions or regulatory constraints. • Further research in breeding, genetics, and irrigation will be necessary to maintain perennial agricultural production. Extreme heat events will challenge agricultural production and raise the risk of food insecurity. California is the largest agricultural producer in the United States, and climate change and extreme heat may significantly affect the state's food production. This paper provides a summary of the current literature on crop responses to extreme heat, with a focus on perennial agriculture in California. We highlight contemporary trends and future projections in heat extremes, and the range of plant responses to extreme heat exposure, noting the variability in plant tolerance and response across season, crop, and cultivar. We also review practices employed to mitigate heat damage and the capacity for those practices to serve as adaptation options in a warmer and drier future. Finally, we discuss current and future research directions aimed at increasing the adaptive capacity of perennial agriculture to the increased heat exposure anticipated with climate change. Collectively, the literature reviewed makes clear the need to understand crop responses and tolerances to heat within the context of climate change and climate extremes in order to sustain crop production, preserve agricultural communities, and bolster food security at local, national, and global scales. [ABSTRACT FROM AUTHOR]