S06 - Session P3 - Combining Microgreens cultivation and biostimulant application in hydroponic systems accentuate yield, quality and economic profitability of functional food

Authors: Christophe El Nakhel *, Michele Ciriello, Luigi Formisano, Marios Kyriacou, Youssef Rouphael

Health-boosting vegetables characterized with gastronomic pleasure is exactly the quest of modern times due to the benefits that humans can assume from the phytochemicals present in plants. Vegetables are rich in biologically active specialized metabolites. Microgreens are an example of such functional food with vivid colors and intense flavors. In addition, it has a short cultivation cycle, suits indoor farming as well as vertical farming and is characterized by a minor footprint regarding water, and fertilizers. Microgreens could even thrive better with the modulation of some pre-harvest factors like the application of biostimulants in the applied nutrient solution. Biostimulants such as protein hydrolysates are rich in free amino acids and small peptides that could boost microgreens yield even during short growing cycles. Therefore, vegetal protein hydrolysates were applied at 0.3 mL/L in a quarter strength nutrient solution to grow Lepidium sativum L. and Brassica oleracea L. var. gongylodes in a floating raft system. The application of biostimulants proved beneficial but genotype dependant, since the yield increased in different proportions among the two tested microgreens species, yet beneficial for both based on an accurate economical study. Yield increase was also combined with an increase in shoots and roots dry matter. In addition color attributes of both species was ameliorated under protein hydrolysates application, where brightness was decreased and a* was increased. The economic profitability of biostimulant applications was also assessed. The combination of biostimulants and floating system proved to be economically useful for growers and a sustainable way to reduce fertilizers application but still increasing the yield of emerging microgreens.