Comparative study on lettuce cultivation within Fieldlab Vertical Farming : Comparative study on the cultivation of lettuce in indoor farms of WUR, Delphy, Logiqs, Vertify and Philips Horticulture LED Solutions

Samenvatting

Within the Fieldlab Vertical Farming project, a comparison study on the cultivation of Caipira lettuce variety was conducted in the indoor facilities of participants Delphy Improvement Centre, Philips Horticulture LED Solutions, Vertify, Logiqs and WUR Greenhouse Horticulture. The facilities differ in size and technical set-up. The same inputs were used, e.g. the climate settings. When analysing the climate collected by the sensors, we observed that the programmed climate conditions were achieved at room level for most of the companies, indicating that farms performed as programmed. However, when looking at climate measured around the crop, climate conditions deviated from the setpoints and were significantly different among the partners. This was the result of the location where the climate was measured, and the way the climate was controlled, for example by wind speed and humidity control. Lettuce heads from the cell with the lightest heads had a 70% lower fresh weight compared to the cell with the heaviest heads. The reduction in weight was due, among other reasons, to 37% lower DLI. The other main factor contributing to differences in fresh head weight was a difference in transpiration due to variation in climate realization around the crop.