Using plant circadian programs to optimize agrochemical use

Agrochemicals play an important role in maximizing agricultural yields. One class of agrochemicals is herbicides, which are used for weed control and to kill the top growth of certain crops before harvest. We examine the influence of plant circadian regulation on herbicide effectiveness to exemplify how knowledge of the circadian clock could be mobilized to optimize agrochemical use. First, we briefly introduce the circadian clock, highlighting its role in plant fitness and regulating physiological and metabolic pathways. Second, we discuss principles of chronotoxicity and the range of herbicides across which agrochemical interventions might be optimized with knowledge of circadian rhythms. Using existing data, we find that a substantial number of pathways targeted by herbicides are subject to circadian clock regulation, opening the possibility that clock control of herbicide effectiveness could be widespread. Finally, we suggest potential practical applications, explaining how this could enhance resource use efficiency, reduce inputs, and mitigate environmental impacts.