Professor Alex Webb, heads up a research group in the Department of Plant Sciences at the University of Cambridge. The group is working out how plants measure time by studying a 24hr timing device called the circadian clock. The research identifies how timing provides benefits to plants maximising plant growth and productivity.
Here Professor Webb, a keynote speaker at the REAP 2021 conference, explains the importance of chronoculture, the use of the circadian biology of the plant to improve crop production.
As scientists, we know from the lab that time of day is important for treatments – herbicides are more effective when sprayed at dawn than dusk – but there is not much evidence that in current agricultural practice, timing of treatment is being considered. This is probably because it is only recently that the technology has become cheap enough to justify the investment.
The chronoculture idea is not just about the plant – it’s also about the fact that automation is now incredibly cheap.
25 years ago, it would have been ridiculously expensive and time consuming to optimise watering by computer. But now, somebody subscribing to a smart app can have automated watering for the cost of a few pounds – and suddenly these smaller benefits can start to accrue.
For example, if it was shown that watering at night would be more beneficial for the plant it would be possible to input this knowledge into the algorithm used to control irrigation. However, if the temperature is very high during the day and it is found that water is beneficial for cooling then the system could override these rules and sprinkle the crop. This dynamic decision making would balance the yield benefit with the cost of the water.
Fundamental research unlocks the secret of timing
Alex Webb’s team at the Department of Plant Sciences, University of Cambridge, had a major breakthrough when they discovered circadian clocks increased the size of the plants they were studying, confirming that this timing mechanism provides an advantage to plants.
Further research revealed that sugars produced by the plant regulate the clock function and calcium controls the circadian rhythm.
Professor Webb says we are at a tipping point where “we’ve got the fundamental biological knowledge and we’ve got the means to exploit it – with expensive automation like robots, cheap automation like smart irrigation, with smart data analysis tools and the ultimate: Controlled Environment Agriculture.”
Our findings about the importance of circadian rhythms in plants and the role of calcium and sugars in regulating their clocks are really fundamental discoveries that help us to understand the biology of the plant. I think this has been the exciting intellectual challenge for the past 25 years!
Now we more or less understand how plants measure time. The big excitement is that these discoveries don’t just apply to daily rhythms, they probably also apply to drought stress biology, pest resistance biology and much more.
We might be able to help adapt plants to different geographies, with different day lengths or breed for a changing environment.
It is already possible to get multiple harvests of wheat in a year under controlled conditions. This is achieved by giving the plants 18 hours of light, four hours of darkness – extreme photoperiods. This is an example of a really radical controlled environmental condition to rapidly accelerate the generation time of wheat – a real example of chronoculture.
But is this applicable in a field environment? For this we need crop data, and my lab is currently working with NIAB and BASF on field trials with wheat. We are growing plants in which the circadian clock is disrupted to see the consequence on different traits.
An application for this could be to adjust harvest time to coincide with optimum environmental conditions, particularly if we have trend towards wet Augusts and warmer drier Autumns.
We now have the opportunity to monitor the plant and control its environment 24 hours a day, which is a significant change in our relationship to farming.
This extends to storage and increasing the shelf-life of fresh produce.
For example, Beko have just released a range of ‘harvest fresh’ fridges which use blue and red lights in the vegetable drawer to simulate a 24-hour sun cycle which mimics natural light conditions ‘to maintain vitamins for longer’.
This feature came directly from fundamental research, where it was found that maintaining a light/dark cycle after harvest reduces pest attacks and maintains the quality of the fruit and vegetables because it stops them whitening and senescing – particularly in brassicas. The papers on this were only published only about 10 years ago.
The big question is: where will this new knowledge bring the best returns?
REAP 2021: Changing Time(s) for Agriculture – 10th November 2021
Imagine a world where agriculture is not constrained by time. The ability to manage and manipulate time is increasing and REAP 2021 will explore the advances in technology and breakthroughs in science that is making this possible.
REAP brings together people from across the agri-tech ecosystem who believe that innovation is the engine for change. The conference bridges the gap between producer needs and technology solutions and showcases exciting agri-tech start-ups.