LED in rozen het moet beter!

Red Naomi! roses were grown under full LED and cooling in the summer of 2017 in a similar way as in 2016 with good results. At the end of October 2017, LEDs with an adapted spectrum were placed in 1/3 of the compartment. The quality problem again occurred under the red /blue spectrum, but in a lesser degree. Equal input of heat via the OPACs and pipe rail system had a favourable effect on the temperature distribution in the crop and thus on the development of the stems. Also crop treatments such as cutting strategy and bending have contributed to a better quality. The adjusted spectrum gave slightly larger buds, larger leaves and less thorns. That the “syndrome” was clearly less present under the adjusted spectrum has been confirmed by measures of flower properties, such as bud size, leaf size and number of thorns. In order to achieve sufficient dynamics in air humidity within a 24-hour period, the lightemission screen could not be completely closed. The energy target of 25% savings is realized when compared to a situation where the SON-T would be used as the LED for an equal number of hours. All the heat needed for cultivation, even when using LED lighting, can be collected in the summer by cooling the greenhouse and storage in an aquifer. The shelf life of roses grown under LED was comparable to that of a practical company. The research was conducted by Wageningen University & Research and Delphy in the context of Kas als Energiebron.