Verdamping bij de kop

The ‘Next Generation Greenhouse Cultivation’ aims at a lower night time crop transpiration in order to reduce the energy consumption. This transpiration however needs to stay sufficient for the transport of nutrients to the head of the crop. In this project, it was investigated whether the local transpiration of the head of the crop can be determined from the image of a thermal camera. Transpiration lowers the leaf surface temperature and by determining the temperature difference between transpiring and non-transpiring leaves a measure can be found for local transpiration. This appeared to be possible, but only when the camera image shows both the temperature of the leaves to be studied and the temperature of a nearby non-transpiring reference surface. This requires a good camera system as it was not always easy to select the correct pixels in the images. In order to compare the measured temperature differences with what a normal transpiring leaf can be expected to show, intensive use of the Radiation Monitor has been made. This recently published model gave that interesting results that the detailed information about crop transpiration has now been added as standard output. The project is funded by Kas Als Energiebron, the research program supported by the Ministry of Economic Affairsand LTO-Glaskracht Nederland