The authors are grateful to the project AgroLabs that has been developed under the Programme Interreg V-B Balkan – Mediterranean 2014-2020, co-funded by the European Union and National Funds of the participating countries. Also, the authors are grateful to the Foundation for Science and Technology (, Portugal) and FEDER under Programme PT2020 for financial support to CIMO (UID/AGR/00690/2013), A. Fernandes (SFRH/BPD/114753/2016) and L. Barros contract; also to FEDER-Interreg España-Portugal programme for financial support through the project 0377_Iberphenol_6_E.
The present study evaluated the impact of phosphorus application rate on plant growth and physiological parameters, antioxidant activity, chemical composition, and essential oil yield and composition of hydroponically grown spearmint plants. Increased P levels resulted in high dry matter content of the aerial part. Antioxidant activity of spearmint leaves was significantly higher at the highest P levels. Although essential oil yield was not affected, essential oil composition varied among the studied P levels, especially carvone content. Total and individual organic acids content was higher when 50 mg/L P were added in the nutrient solution. Rosmarinic acid was the main detected phenolic compound, while the highest total phenolic compounds and rosmarinic acid content was observed at 50 and 70 mg/L of P, respectively. In conclusion, phosphorus application rate may affect spearmint growth and development, as well as chemical composition and essential oil composition.
