Light interception was measured by Wageningen University & Research Greenhouse Horticulture at two nurseries with cucumbers in a high wire system and a different orientation of the LED-interlighting. The canopy density appeared to be very important for the light interception and up and down light loss. The total light loss to the greenhouse cover and floor was 17 en 34% on both nurseries, respectively. In the middle of the path between crop rows, 17 and 34% of the LED light was still measured, respectively. However, this light will largely be captured by plants of the neighbouring row. The measured interception of the sunlight by the plants, was on both nurseries respectively 96 and 87%. Per 1% additional LED light, a production increase of 0.8% was realised. The project was funded by Kas als Energiebron.