Prof. Dr. Leo Marcelis is head of the chair group Horticulture and Product Physiology at Wageningen University, The Netherlands. This group holds a strong position in research and education on greenhouse horticulture, vertical farming and post-harvest quality. His research focuses on sustainable production of high quality products in vertical farms and greenhouses; Leo has a strong background in plant physiology, crop monitoring, computational modelling and experimentation. He has extensively studied the physiology, growth and development of plants in order to improve sustainability and quality of crop production in greenhouses and vertical farms. In particular fluxes of assimilates, water and nutrients in the plant, sink/source interactions and partitioning among plant organs in response to abiotic constraints are subject of study. LED lighting is a major theme in his research. At the moment he is leading large multidisciplinary research programmes on vertical farming and LED lighting in greenhouses in which universities and private companies cooperate.