Macroelement omission in hydroponic systems changes plant growth and chemical composition of Melissa officinalis L. essential oil

Abstract

Macronutrients are essential to several metabolic reactions in plants, as well as to the normal development of vital plant activities. The aim of the current study was to evaluate growth, as well as the content and chemical composition of Melissa officinalis L. essential oil, in plants subjected to mineral omission. The experiment was carried out with Hoagland & Arnon nutrient solution in a hydroponic system, based on the missing element technique. Seven treatments were evaluated: one comprised all nutrients (full treatment) and six missed one nutrient in each solution (-N, -P, -K, -Ca, -Mg, and -S). The increasing order of limiting nutrients for total dry weight was N > K = Ca = P > S = Mg, and that for essential oil content was N > Ca > S = K = P > Mg. Nutrient omission also affected content and chemical composition of its essential oil. Omission of Mg increased chlorophyll, carotenoid and essential oil contents. Thus, it is possible establishing adequate macroelements management to achieve higher growth and content of essential oil.