Demokas 2030: emissiearm telen potanthurium met low-e glas: Teelt 2023-2024. Test Low- e glas en nieuwe LED-spectra bij potanthurium: aanvulling op het rapport WPR-1366 en WPR-145

In Greenhouse 2030 a low-emission cultivation of pot Anthurium was demonstrated with funding by the program “Greenhouse as Source of Energy”. In the fifth and last year (autumn 2023 to autumn 2024), further steps were taken towards a zero-emission cultivation. This year, three innovations were added: a greenhouse cover of diffuse glass with low-emission coating, three LED light spectra, including two with additional far-red, and the use of the brown lacewing as aphid control. The survival of entomopathogenic fungi as potential addition to the natural enemies was also tested. Seven potted anthurium cultivars were grown along with smaller batches of Monstera, Calathea, and Kalanchoë. The zero-emission goal for energy is achieved: 138 kWh/m² sustainably produced electricity were enough for lighting, conditioning and heating the greenhouse for the whole year, with a positive effect of the low- ε glass against radiation losses. From the LED spectra comparisons, FR-rich light proved essential for controlling flower stem elongation, with a spectrum of 85 % red and 19 % added FR offering a good compromise between the effects on elongation and energy efficiency. The zero-emission target for crop protection products was achieved in the winter. However, four chemical treatments were necessary in the summer to control aphids and leafhoppers. The zero-emission target for fertilizers was also achieved. Plant growth increased by 30–40 % compared to commercial greenhouses. Other potted plants also responded promisingly.