News
Signify and WUR continue collaboration in IDC-LED
Signify (Euronext: LIGHT) and Wageningen University & Research are extending their collaboration in the Innovation & Demonstration Center in Bleiswijk for the application of dynamic LED lighting in horticulture (IDC-LED). This will allow their research into energy- and cost-effective lighting strategies for horticultural crops to continue.
The IDC-LED has been located at the research site of Wageningen University & Research in Bleiswijk since 2013. It includes two greenhouses with twelve and fourteen cultivation tables, and a greenhouse with four compartments for high-wire cultivation. All the cultivation tables and compartments can be lit separately by LED modules that can be individually controlled for intensity and light spectrum (blue, white, red and far-red light).
Ground-breaking research
In the past ten years, groundbreaking research has been conducted on the effect of light recipes for horticulture. This has contributed to an accelerated switch from HPS installations to energy-efficient LED installations at horticultural companies that grow crops under artificial lighting. “It is not uncommon for the results to be applied one-on-one in practice," says lead researcher Anja Dieleman of Wageningen University & Research. “For example, full LED light recipes have been developed for rose, cucumber, chrysanthemum and alstroemeria. Growers are achieving good results with the full LED installations at a much lower electricity consumption compared to HPS.”
Minimal amount of light is sufficient
A new project which was started last year and is funded by Kas als Energiebron (Greenhouse as Energy Source) looks further into dynamic lighting opportunities. Anja Dieleman explains that in the IDC-LED experiment, young tomato plants were subjected to various lighting conditions, where the lamps were either dimmed or switched off for varying durations and to different extents. The growth of tomato plants under constant light intensity was compared with those that experienced intermittent light intensity, which was either switched on and off or dimmed every minute or every half an hour.
Switching on and off at full light intensity resulted in a lower chlorophyll content, less photosynthesis and lower plant weight. Strategies in which the light was not switched off, but dimmed every minute or half hour, yielded similar results to continuous full lighting. “Our conclusion is that a minimal amount of light is enough to keep the growth process going, and that tomato plants can then respond quickly to changes in light intensity. Temporary dimming is therefore clearly preferable to temporarily switching off light installations.”