The Hidden Costs of Nighttime Warming on Yields

Highlights

• Nighttime warming is reducing crop yields worldwide, threatening global food security.

• This phenomenon is more complex than may be assumed, likely to involve interaction between two driving forces: nighttime temperature and evaporative demand.

• The two conspire to limit carbon availability for yield and end-use quality traits while decreasing water use efficiency, potentially enhancing vulnerability to droughts.

• An ecophysiological framework is proposed as a guide to implement future research efforts to mitigate yield declines.

• Such efforts should integrate physiology with crop modeling, breeding, and management to identify sustainable pathways for mitigation as climate change intensifies.

Nighttime warming poses a threat to global food security as it is driving yield declines worldwide, but our understanding of the physiological basis of this phenomenon remains very limited. Furthermore, it is often assumed that such declines are driven solely by increases in nighttime temperature (T_Night). Here we argue that, in addition to temperature, increases in nighttime evaporative demand may ‘conspire’ to penalize yields and end-use quality traits. We propose an ecophysiological framework outlining the possible mechanistic basis of such declines in yield and quality. We suggest ways to use the proposed framework as a guide to future efforts aimed at alleviating productivity losses by integrating crop ecophysiology with modeling, breeding, and management.