The Impact of Glutamic Acid Foliar Application on Physiological and Biochemical Attributes of Stevia Rebaudiana at Greenhouse Conditions

Stevia is a perennial herbaceous plant belonging to the Asteraceae family that is used as a natural sweetener in the pharmaceutical and food industries today. In order to investigate the effect of foliar application of glutamic acid on some growth parameters and biochemical traits of this plant, different concentrations of glutamic acid were applied. Treatments included ۰ (control), ۵۰, ۱۰۰, ۱۵۰ mg/l glutamic acid, which conducted based on completely randomized design with three replications in greenhouse growth conditions. All treatments were applied at four stages with an interval of ۱۰ days. Based on the results, the highest amount of shoot growth (۴۷.۳۵ cm) and TSS (۱.۷ %) as well as the maximum number of leaves (۱۰۸) were obtained by ۱۵۰ mg/l glutamic acid. The highest amount of total chlorophyll (۱۱.۸۶ mg/g FW) and total phenol (۳۴۹.۸۷ mg/g FW) were observed in ۵۰ mg/l treatment. Generally, the results showed a positive effect of leaf foliar application of glutamic acid on the studied traits of stevia plant however, it needs further research to reveal the effect of these kinds of treatments on steviol glycosides.

Keywords:

amino acid , foliar spraying , glutamic acid , Stevia rebaudiana.