Yield, taste and time to harvest can all be impacted by light. So, increasing the rate of photosynthesis, the process by which plants convert sunlight to biomass, has the potential to improve agricultural productivity and the nutritional value of the crop. Technologies to extract greater value from available light and the feasibility of year around production of green vegetables are among the topics to be discussed at the Agri-TechE event ‘Let there be Light’ hosted by the University of Essex Plant Innovation Centre on the 22nd February.
This in-person event will include an exhibition with the chance to talk directly to those at the leading-edge of these technologies.
Could Glaia ‘sugar dots’ increase rate of photosynthesis in field crops?
Field crops could also benefit from technology to accelerate the rate of photosynthesis. Agri-tech start-up Glaia is achieving this by using a naturally occurring carbon-nano material to create ‘sugar dots’ that can be sprayed on to foliage. Once located on the leaves the dots increase the number of light-harvesting antenna, improving the response to light. When applied to wheat, strawberries, and tomatoes they have been shown to increase yields between 20-40%.
Could UK be self-sufficient in leafy greens?
A blended approach of field and undercover cropping may increase the UK’s potential to be self-sufficient in leafy greens, says University of Essex researcher John Stamford, who is looking at how to use tailored LED lighting recipes to improve crop performance and yield as part of the Interreg2Seas funded Hy4Dense project.
“Speaking to farmers, there are a few issues around the supply of leafy greens in the supermarkets. Around November production switches from the UK to Spain which means we are importing these crops over the winter months. The idea here is to improve accessibility of hydroponics in order to potentially have cost-effective year-round UK production. Light plays an important role in that.
“For instance, growing under red light for the first few weeks may cause the plant to focus more on biomass growth, and then transitioning into blue light in the last week before harvest, the plant is stimulated to generate a range of pigments, secondary metabolites, and flavour compounds. So that could maximise yield and flavour in the crop.”
John has experimented with artificial day lengths and changing the quality of light that a plant receives over time to see the impact that has on flavour and other properties: “A plant responds to light quality and quantity in order to optimise itself for the environment, and we can use this response to customise the flavour and morphology of the plant. Some consumers have a preference for larger, leafier, plain tasting leaves whilst others prefer smaller, more flavourful leaves.”
But still challenges to overcome
Lighting can also be used to reduce time to harvest, according to research by Jim Stevens of Vertical Future, an engineering firm that designs controlled environments for clients. Vertical Future recently announced a £21million fundraising round, which will be used to boost its development pipeline and widen the options of what can be grown.
Jim explains: “Growing lettuces at supermarket prices in vertical farms may be feasible if we can get their growth cycle down from eight weeks to six or even five. The problem is, lettuces suffer from tip burn, especially if they grow too fast. These ugly brown spots on the leaves are caused mainly by slow transpiration of water through the plants and are unsurprisingly rejected by consumers.”
“One option is to change the light spectrum to increase transpiration at higher light levels – for example turning up the blue spectrum to trigger the plant’s stomata to open and cool the plant.”
Other speakers at ‘Let there be light’ include:
- Molly Allington, CEO of Albotherm, whose heat-sensitive shade coating optimises the amount of light entering the glasshouse or polytunnel
- John Matcham, Technical Director of Light Science Technologies, developers of novel lighting recipes for a variety of environments
- James Millichap-Merrick, CEO of Vitabeam, whose ‘Quantum Energy’ lighting has been shown to boost yield and extend shelf-life of fresh produce.
The exhibitors include:
- Kroptek developer of LED grow lights, the company recently announced a collaboration with Surexport to fast-forward the strawberry season by a full month with the best quality of fruit.
- GE Current – providers of professional horticultural lighting solutions for greenhouses and indoor farms
- Pro-Lite – portable plant science instruments that measure and analyse everything from roots to leaves including rate of photosynthesis, canopy structure, leaf area, spectroscopy, and root function.
- Glaia – developers of nanotechnology-based solutions for sustainable agriculture