S06 - Session O2 - Improving energy efficiency of ornamental plant cultivation in winter and spring.

Authors: Kees Weerheim *, Myrthe Mahakena

The cultivation of green potted plants occurs in relatively high temperatures, whereby the amount of light is strongly limited. In addition, peak heat consumption in cold and dark periods is an important characteristic of this crop. Climate-neutral cultivation of potted plants is therefore a challenge, which differs depending on the individual company situation. Important tools growers have are efficient use of natural light and heat, good insulation, and a cultivation strategy according to the Next Generation Growing. The production of assimilates is important because there is little natural light in winter and high heating requirements to maintain quality. In two compartments, a practice-based cultivation is compared with a sustainable cultivation concept including emulation of a higher light transmission. In the winter period, a significant improvement in energy efficiency was possible by increasing light intensity but reducing heating input while maintaining or increasing biomass production depending on the species. In spring, the stomatal opening was considerably reduced compared to the reference cultivation due to a higher water vapor deficit. Overall, considerable energy savings in winter conditions are possible when light transmission is maximized and energy screens are used extensively. Improvement of the cultivation method in spring may lead to increased productivity under higher light conditions.