Effects of high intensity LED light, diffuse glass and improved climate on Alstroemeria photosynthesis and production

An innovative cultivation system for Alstroemeria growing, designed to be fossil fuel free for heating and lighting and to increase productivity is investigated under the working title “Cultivation of the Future”. The first goal is achieved by a better isolation of the greenhouse, use of heat produced by the supplementary lights and the soil cooling machine and use of latent heat; the second goal is reached by the increase of the intensity of supplementary lights, the replacement of the HPS lights by LED and the provision of a less stressful environment. This cultivation system was compared to a “traditional” Alstroemeria cultivation system in the Netherlands. For the experiment, two greenhouse compartments and two Alstroemeria cultivars were used. During the first 11 months of the experiment, the “Cultivation of the future” had 31 and 34% higher generative stem production, for the cultivars ‘Noize’ and ‘Virginia’, respectively, than the reference cultivation system. It was concluded that production gains were caused mainly by the higher light sum in the winter months, and by increased stomatal conductance and higher photosynthesis capacity in the summer period, caused by the milder climate provided by a lower VPD and the highly diffused incident light.