Like humans, plants have a circadian rhythm, or biological clock. Scientists suggest that following plant circadian rhythms when making decisions on herbicide application could require less of the chemicals and make them more effective.
The death of plant tissue and slowing of growth after using the herbicide glyphosate, known as the active ingredient in Roundup, depends on the time of day it is applied, according to research published Friday in the journal Nature Communications.
Glyphosate is one of the most widely used herbicides in the world, however levels of the chemical used in agricultural production have raised health concerns, and also pose challenges for farmers.
Dr. Antony Dodd, a researcher at the University of Bristol and senior author of the new paper, said a method of chronology — the practice in human medicine of timing doses of medication to a patient’s circadian rhythm — could help improve and sustain the agricultural production the growing human population needs.
“This proof of concept research suggests that, in future, we might be able to refine the use of some chemicals that are used in agriculture by taking advantage of the biological clock in plants,” Dodd said in a press release. “Approaches of this type, combining biotechnology with precision agriculture, can provide economic and environmental benefits.”
For the study, Dodd and his team tested the timing of glyphosate application, finding that it was most effective at dawn — plants were especially sensitive at this time — as opposed to dusk.
They noticed, however, that transport processes within plants and leaf position may be circadian-regulated, suggesting an even more detailed understanding of the best time to spray can be found.
Future research, they say, should be focused on identifying the specific biological processes to determine how to better optimize the use of glyphosate and other herbicides.
“The pervasive influence of circadian regulation upon plant metabolism suggests that the principle we identify might scale to other agrochemicals,” the researchers wrote in the paper. “The circadian regulation of plant responses to agrochemicals provides a basis to refine agrochemical development and use, through this novel concept of agricultural chronotherapy, to optimize crop protection for food security.”