Macronutrient Suppression in Nutrient Solution Alters the Growth and Citral Content of Cymbopogon flexuosus

Cymbopogon flexuosus Stapf is a medicinal species cultivated on several continents. The essential oil extracted from its leaves has relevant commercial value and is widely used in flavoring agents, fragrances, perfumery, cosmetics, soaps, and detergents as well as in the pharmaceutical industry. This study evaluated the effect of macronutrient suppression on the growth, visual diagnosis, content, and chemical composition of C. flexuosus essential oil in a hydroponic culture. A completely randomized design with four replicates was used, with three plants per pot in each replicate. The treatments were characterized by suppressing the macronutrients, N, P, K, Ca, Mg, and S, under the missing element technique. After 90 days of cultivation, the deficiency symptoms were photographed and characterized. The dry biomass of the roots and shoot, root-to-shoot ratio, number of tillers, leaf analysis, content, yield, and chemical composition of the essential oil were evaluated. Macronutrient suppression in a hydroponic culture influenced growth and chemical composition of C. flexuosus essential oil. Total biomass production was more limited in potassium and magnesium omission. Suppressing sulfur promoted an increase in content and yield of essential oil. The highest citral content was observed in phosphorus and nitrogen omission.