Dynamisch belichten in jonge tomatenplanten: grenzen en mogelijkheden: Deelverslag IV van project LED licht met de zon mee

Increasing costs of electricity make it interesting for greenhouse horticulture to alter its lighting strategy, in which lighting is used when electricity prices are low and lights are switched off or dimmed when electricity prices are high. In this study, effects of light fluctuations differing in frequency and amplitude on the growth and morphology of young tomato plants were investigated. Light fluctuations per hours, 30 minutes and minute with 125/75, 175/25 and 200/0 μmol/m2/s were compared with continuous light, where the light sum per day was the same. Total above-ground biomass was lower for the treatments where the light fluctuated between 200 and 0 μmol/m2/s regardless of the frequency used. Chlorophyll content, light absorption and photosynthesis also decreased. Light changes in which a minimum light level was maintained (125/75, 175/25 μmol/m2/s) had comparable results to continuous light. These results indicate that a minimum light level is sufficient for a plant to cope with light changes, while maintaining development rate and growth.