Groei en productie van freesia onder verschillende lichtkleuren, daglengtes en lichtintensiteiten: Deelrapport I van het project “LED met de zon mee”

To reduce the energy consumption, an increasing number of crops switch to LED lighting. As LEDs produce less heat than HPS lighting, they match well with relatively cold grown crops such as freesia. The Business unit Greenhouse Horticulture and Flower Bulbs of Wageningen University & Research tested which lighting strategy freesia growers can use best, to get optimal benefits of their LEDs. A daylength of 16 hours 150 μmol/m2/s was compared with 12 hours 200 μmol/m2/s with the same total light sum (8.6 mol/m2/day). Depending on the variety, the daylength of 12 hours resulted in an equal or higher production, which was even equal or higher than the production at 16 hours 200 μmol/m2/s with a total light sum of 11,5 mol/m2/day. A higher or lower percentage of blue light had no significant effect, although there was a trend towards a higher production. The expectation was that addition of far red light would increase stem length. However, far red light resulted in faster flowering and side shoots that were positioned higher on the main stem and were shorter. This research is part of the research project ‘Led with the sun’ and was financed by the ‘Kas als Energiebron’ program to stimulate the implementation of LED lighting.