Open Access

Sebastian Deck, Nils Kreß, Wiebke Niether, Elsa Hegmann, Christina Rohsius, Andreas Ulbrich

• Climate change increasingly disrupts cocoa cultivation in tropical regions, particularly through erratic rainfall and rising temperatures. Innovative approaches to sustainable production are urgently needed. Hydroponic systems, with their ability to precisely manage water and nutrient inputs, could offer promising additions to conventional soil-based cultivation methods, especially under stress-prone conditions. They also serve as effective platforms for experimental research on plant physiology in controlled environments. This study explored the establishment of a hydroponic protocol for Theobroma cacao L. under greenhouse conditions in Germany. A recirculating drip-irrigation system with automated water and nutrient supply was developed and optimized. Young cocoa plants (seedlings) successfully adapted to the hydroponic environment, showing continuous vegetative and generative growth, including flowering and initial fruit set, within less than one year. These findings contribute to refining hydroponic methods for perennial tropical crops and offer a reproducible framework for future research on climate-resilient cocoa cultivation systems. The developed protocol can serve as a reference for applying hydroponic principles to tropical open-field settings. Furthermore, it facilitates more precise studies of physiological stress on plant development - such as temperature fluctuations or pruning - and provides insights into the timing and intensity of flowering and fruit development under Controlled Environment Agriculture conditions.