Influence of foliar application with amino acids and citric acid on physiological and phytochemical responses of Artemisia abrotanum produced by in vitro culture

The physiological and phytochemical responses of Artemisia abrotanum to foliar application of different concentrations of amino acids (tryptophan and phenylalanine) and citric acids acid were studied during two successive seasons (2014-2015). The results showed that foliar application of either amino acids or citric acid significantly promoted the growth parameters in terms of plant height, a number of branches, fresh, and dry biomass. All treatments led to significant increments in essential oil content and yield. Plant growth and essential oil parameters gradually increased with amino acids or citric acid concentrations. Gas-liquid chromatographic analysis revealed that the major identified components of essential oil were Chamazulen, p-Cymen-8-ol and piperitone. Organic and amino acid treatments resulted in improving quantity and quality of essential oil components.