Komkommer integraal naar een optimaal lichtspectrum : ontwikkeling van het IDC LED Hoge Draad en onderzoek naar het LED lichtspectrum in komkommer

In horticulture, supplementary LED lighting is increasingly used to increase and optimize crop growth during winter and reduce energy costs compared to conventional lighting. However, practical application is not always energy-efficient due to limited understanding of plant light spectrum requirements. Light spectrum influences crop morphology, biomass production, assimilate distribution, and pest and disease resilience. This study investigated the effects of LED light spectra on biomass production, development, and resilience of two Cucumis sativus cultivars. Far-red light was added to or partially replaced photosynthetic photon flux density (PPFD), resulting in varying photon flux density (PFD) levels, in addition to a treatment partially replacing red light with blue and green LED light. Cultivar-specific responses were observed: stem- and petiole length consistently increased under higher FR doses. Fruit production decreased under higher FR at lower PPFD but increased when FR was added on top of the PPFD. Leaf photosynthesis improved when FR was added to PPFD but not in combination with increased blue and green light. FR increased resistance to thrips and influenced powdery mildew establishment. Gene expression analysis highlighted changes in resistance and flavonoid biosynthesis genes. These findings emphasize the critical role of LED spectra in sustainable greenhouse systems.