LED trials to strengthen UK food security
Using LED lights can enable the UK to grow crops at different times of the year

LED trials to strengthen UK food security

Rachel Anderson

Dr Martin McPherson, science director at Stockbridge Technology Centre
Dr Martin McPherson, science director at Stockbridge Technology Centre

Dr Martin McPherson, science director at Stockbridge Technology Centre (STC) near York, shows Produce Business UK around the state-of-the-art LED 4 Crops facility, where he and his team are carrying out groundbreaking research for the fresh produce industry

What is LED 4 Crops?

Dr Martin McPherson: LED 4 Crops refers to the facilities we have at STC that enable us to research the effects of LED (light-emitting diode) lights on fresh produce and ornamental crops. These facilities include our new, LED High Wire facility, which is currently trialling different lighting formulas on Sunstream tomatoes, and our original insulated warehouse (or urban farm), which relies entirely on artificial LED lighting for crop production.

Which companies have helped STC to create these LED 4 Crops facilities?

MM: STC – an independent, not-for-profit organisation which carries out research for the UK’s horticulture industry – set up the original warehouse facility in partnership with lighting specialist Philips Horticulture LED Solutions and the glasshouse firm CambridgeHOK. Our new glasshouse facility, which was officially opened in December (2014) by the Rt Hon Michael Jack CBE, is being supported by a consortium of many different companies. These include Philips and CambridgeHOK and Cornerways nursery with support from the British Tomato Growers Association. In addition, various firms such as East Yorkshire-based propagators Plant Raisers, the seed company Enza Zaden, and hydroponic substrate supplier Grodan are providing in-kind support.

Can you tell us more about the work you are doing in your LED High Wire facility?

MM: We are trialling four different lighting treatments on tomato crops. The glasshouse is therefore divided into four, 200m2 sections, with each section using a different lighting treatment. The treatments are:

  • High pressure sodium (HPS) lights on the top of the crop, which is the control plot.
  • A mixture of HPS lights on the top of the canopy and LED interlights (LED lights that are suspended within the crop).
  • A combination of LED top lights and LED interlights.
  • A mixture of LED top lights, LED interlights and diffuse glass, which enables light to better penetrate the crop.

What will be the outcome of the project once it finishes this summer (2015)? For example, do you expect British tomato growers to start investing in these technologies?

MM: A lot of what will happen will depend on the outcome of our trials. It will also depend on the economic return of the crop, i.e. can growers afford to invest? That’s why it’s important that we do the work here first, rather than growers taking a risk themselves. That’s the basic principle. Once we get our results, growers will probably start with small areas [of LED-lit crops], and see if they are happy with that.

What impact could the use of LEDs have on the supply chain?

MM: Using LED lights can enable us to grow these crops at different times of the year, such as through the winter period, therefore extending their season and enabling year-round production. The use of the technology ties in with the government realising that food security is important – that there is a resilience issue. The UK has to be able to make sure that it can source the product it needs – can we always assume that we can import? But can we use this technology cost effectively and economically, so that our growers are able to make money out of it? No one has the answer to that just yet.

Can you tell us about the work you are carrying out in your insulated warehouse?

MM: A lot of the work we are carrying out inside this space is confidential, but in the past we have, for example, worked on a project with Mack and Wallings Nursery in Essex. This project was supported by Sainsbury’s and saw us help the nursery to extend its strawberry season by trialling different light recipes on strawberries. Currently, we are running trials on crops such as basil (herbs), strawberries and geraniums. The crops are grown on benches that are stacked one on top of the other. We are trialling different light recipes so that we can create bespoke recipes for individual crop species. Once we have the right recipe we can start thinking about developing the most cost-effective way of growing the crop – such as extending day length. All of the settings inside this environment, such as lighting and temperature, are computer controlled.

Other than extending their season, what benefits can growing in this environment bring to the crop?

MM: We are beginning to understand that growing crops in this way can improve their quality in many different ways, from their shape and colour to their flavour and nutritional value. We could, for example, increase plants’ vitamin C content. We already know that we can grow red lettuce year-round in the UK under artificial light.

What has been the reaction of produce buyers to this technology?

MM: We are aware that there’s significant retail interest in this technology. We are interested in talking to retailers, particularly about where we go from here. A lot of our funding comes through commercial resources so the more we can work with the retailers, processors and grower groups the better.

How do you see this technology being used in future?

MM: LED technology is becoming more efficient. The price of solar panels has halved in the last two years so these technologies are helping to justify this type of production. There are lots of existing warehouses sitting empty at the moment that could be used as urban farms. They would also reduce transport costs – the ultimate goal is to be carbon neutral. A couple of large-scale, indoor farms are already being run in a few other countries, including the US and Japan. There, they are using urban farms to grow lettuce. But in Japan, the retail value of that crop is currently higher than it is in Europe.



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