Soilless cucumber production in heated greenhouse : physiological references acquisitions and proposition of news climatic controls tools ; Culture hors sol de concombre sous serres chauffées : acquisition de références physiologiques et proposition d'outils d'aide au pilotage du climat

Soilless crops in heated greenhouses allow producers to control some climatic parameters to fulfil plant needs and crop management. However, this control is highly related to high energy consumption, representing 25% of production costs. In this particular context, our study aims to increase energy efficiency of heated greenhouse crops, with a focus on cucumber crop. To achieve these objectives, plant physiology-based experiments were performed to (i) improve photosynthetic performances and (ii) reduce sanitary risks through the use of an innovative sensor for fruit temperature monitoring. Results showed that (i) CO2 injection should be managed considering Photosynthetic Active Radiation (PAR) with the identification of a valuable increase of CO2 content when PAR exceeds 100 µmol PPFD.m-2.s-1.Based on mathematical approach, Leaf Area Index was estimated and could be used as decision making tool for appropriate deleafing and climate control considering optimal crop photosynthetic activity. We assayed (ii) several fruit temperature sensors to provide a tool able to identify condensation risks on plant organs. In our study, strong risks were highlighted between 7h45 and 9h00 am. In perspective, physiological performances could as well be improved by adaptation of high wire training system. Producers will be able to rely on the physiological references obtained in this work to improve energy (and global inputs) efficiency of cucumber crops. ; La culture hors sol sous serre chauffée offre aux producteurs la possibilité d’exercer un contrôle des paramètres climatiques adaptés aux besoins de la culture. Cependant, ce contrôle est fortement relié à des dépenses énergétiques qui peuvent représenter jusqu’à 25% des coûts de productions. Dans ce contexte, notre étude vise à proposer des solutions pour améliorer l’efficience énergétique de ce type de culture, sur une espèce représentative: le concombre. Pour répondre à ces objectifs, la prise en compte des réactions physiologiques de la plante a été privilégiée pour (i) ...