This work was supported by a grant [number PT13100] from the programme ‘Kas als energiebron’ of the Product Board for Horticulture and Ministry of Agriculture, Nature and Food. We are grateful to STW (Stichting Technische Wetenschappen) for funding the technological infrastructure for the photosynthesis measurements, made available within the project “The application of LED technology in plant production” (number WPB.6662).