Tomaten belichten met minder elektriciteit

anglais. Over the last 10 years, the use of electricity for assimilation lighting has increased considerably. It is now an important part of the energy use of the horticultural sector. To reverse this trend, in the lighting season 2013/2014, we conducted a trial with the aim to reduce the electricity use in a lighted tomato crop by 35% while maintaining production levels. Two treatments were applied: (1) Reference cultivation: clear glass and lighting by 50% HPS lamps and 50% LED intermittent lighting (210 µmol/m2/s), (2) energy efficient cultivation: diffuse greenhouse cover and lighting by 50% LED top lighting and 50% intermittent LED lighting (210 µmol/m2/s). In the energy efficient cultivation, 37% less electricity was used in the period October - May. However, energy use for heating in this treatment was higher to compensate for the lack of radiative heat. The light sum the plants received (sunlight + artificial lighting) was 6% lower in the energy efficient cultivation compared to the reference cultivation due to the lower number of lighting hours. However, the production difference was only 0.3 kg/m2, less than 1%! Detailed plant measurements showed hardly any differences between the treatments in light interception, light absorption by the leaves, photosynthesis and the production and distribution of assimilates. The analysis of the crop growth model showed that the effect of the lower number of lighting hours in the energy efficient cultivation was fully compensated by the positive effects of the diffuse greenhouse cover which has a higher light transmission.

néerlandais; flamand. In de afgelopen 10 jaar is het areaal belichte teelt in de glastuinbouw flink toegenomen, evenals de geïnstalleerde vermogens. Daarmee is het gebruik van elektriciteit voor groeilicht een belangrijke post in het energiegebruik van de sector. Om een afname van het energiegebruik te realiseren, is het nu van belang het elektriciteitsverbruik te verlagen, zonder grote gevolgen voor productie en productkwaliteit. Bij Wageningen UR Glastuinbouw is in het belichtingsseizoen 2013/2014 een proef gedaan met als doelstelling het elektriciteitsgebruik in een belichte tomatenteelt met 35% te verminderen met behoud van productie.