FILTERING NATURAL LIGHT AT THE GREENHOUSE COVERING - BETTER GREENHOUSE CLIMATE AND HIGHER PRODUCTION BY FILTERING OUT NIR?

Abstract

Wageningen UR investigated the potentials of several NIR-filtering methods to be applied in Dutch horticulture. NIR-filtering can be done by the greenhouse covering or by internal or external moveable screens. The objective of this investigation was to quantify the effect of different NIR-filtering methods on greenhouse climate, energy saving and growth and production of tomato and to estimate the amount of NIR to be blocked to get positive effects under Dutch climate conditions. In the research is shown that there are technical and economical potentials for filtering NIR by the greenhouse covering or to use a moveable screen, which does not limit ventilation. Tomato production can potentially be increased with 8-12% depending on the NIR-filtering materials used.