Industrial, News

Can LEDs give us juicy tomatoes all year round?

Philips has teamed up with a horticultural research centre in Yorkshire to test the effects of different kinds of lights on how tomatoes grow.

The tomatoes are being grown under 100 per cent artificial light at Stockbridge Technology Centre (STC).

Working with Philips, which has experience of similar projects in the Netherlands as well as an array of LEDs and high-pressure sodium (HPS) lamps, STC hopes to identify the conditions for maximising the year-round yield and quality of the fruit in a controlled environment.

To this end, the roof on one of STC’s glasshouses has been raised to a height of 5.5m. Beneath it there are four compartments in which four different lighting regimes are deployed. For the duration of the research, each one uses a different combination of LED and HPS lights installed above the crop and within the crop canopy.

The extra height of the LED4Crops facility allows for the multi-tiered production that many believe is necessary to meet the nutritional demands of a growing – and increasingly urban – global population. ‘We can potentially ramp up crop production intensively, but sustainably, and provide a level of immunity to climate disruption around the globe,’ said Martin McPherson, STC’s science director.

As installation costs are reduced by improvements in LED technology, Udo van Slooten, director of Philips Horticulture LED Solutions, believes the biggest barrier to the uptake of such technology is scepticism among growers. ‘A large-scale test from an independent research institute is a good way to combat this. Rather than just telling growers about what we can do, they can experience it.’

He is confident they will like what they see, not least because of the way the UK food supply chain works. Big supermarkets, who dominate the retail sector, like to tie their suppliers to long contracts that include strict specifications about the size and quality of the product. If, as STC and Philips say, LED technology can deliver consistently high-quality tomatoes for 12 months a year – even in periods outside of the usual growing season when quality has traditionally dropped – it can give a grower an advantage over its rivals in the fight for those important supermarket contracts.

The ability to fine-tune the wavelengths of LEDs to deliver the characteristics that buyers look for in their fresh produce is a significant advance. Take, for example, the big difference between the British and Dutch tomato markets: consumers in the UK like their tomatoes on the vine; their counterparts in the Netherlands are quite happy with them loose. Good-looking vines are a new factor for Philips to consider, but the adaptability of LEDs means the adjustment should be a straightforward one.

For these reasons, Van Slooten believes that within a few years LED will replace HPS as the ‘dominant’ technology for lighting glasshouses in the UK and beyond.