Basiskennis verdamping komkommer : deelverslag 4 van het project “Kennisontwikkeling over verdamping: van fundamenteel naar toegepast”

An experiment with cucumber was carried out in two cells of the “Vertical Farm” of Wageningen UR Glastuinbouw in Bleiswijk. The aim was to learn more about effects of continuously low transpiration during the night on plant development and production. A difference in the night VD between cells was created to limit night transpiration in one of the cells. Equal conditions were applied in both cells during the day. Transpiration was quantified with weighing gutters. A 59% lower VD at night reduced nighttime transpiration by 43% and slightly reduced the daytime transpiration by 6%. This difference cannot be explained by differences in stomatal density or size between the treatments. The limited night transpiration did not affect the absorption of calcium or other elements. No crop abnormalities were observed. Production and quality were the same in both treatments, possibly because transpiration during the day was not limited. In followup experiments, further limitation of transpiration will be applied alternating night and day to learn more about effects and moments of minimal transpiration. This experiment is part of the collaborative project between WUR, Delphy and Plant Lighting “Knowledge development about transpiration: from fundamental to applied”, funded by the program “Greenhouse as Source of Energy”.