Philips is involved in a trial that began in April 2016 at the Delphy Improvement Centre in Bleiswijk, Holland. In this trial 100 per cent GreenPower LED toplighting with a light level of 200 µmol/m²/s is being used.
The study, which will go on for 18 months, will provide information about the effect of 100 per cent LEDs on the quality and branch weight of roses. The trial ties in with the principles of The New Cultivation: an energy-efficient method of cultivation combined with optimal production. The project is receiving support from the Rose crop cooperative and is partly financed by ‘Kas als Energiebron’ (‘Greenhouse as a source of energy’), the Dutch Ministry of Economic Affairs' and ‘LTO Glaskracht Nederland's’ innovation and action programme.
The aim of the study is to demonstrate that cultivation using 100 per cent LEDs is possible.
"Lighting with LEDs improves the balance between light and heat, allowing screens to be kept closed and creating a uniform climate," says Arie de Gelder, project leader of the rose trial and researcher at Wageningen University and Research Centre. "The main challenge is to be found in the plant temperature at the top of the crop as compared with conventional lighting. We are very curious to see how the rose crop responds to this. Eventually this combination of light and temperature should give rise to a further improvement in quality in the form of larger flowers and higher branch weight."
In rose cultivation, a 25 per cent reduction in electricity consumption can be achieved with LEDs as compared with conventional lighting. A combination of heat exchangers and a heat pump makes it possible to eliminate fossil energy and take a step in the direction of sustainable cultivation, say Philips.
"We expect to be able to move to even higher light levels with LEDs, with control of light and temperature being separated," says Leontiene van Genuchten, plant specialist at Philips. "Many growers are convinced that HPS lamps are required in order to obtain a suitable crop temperature. In this trial we will find out whether we get at least the same result using a different cultivation method."