Comparison Growth Indices and Phenolic Compounds of Stevia rebaudiana growing at Greenhouse and Field Conditions

Comparison growing traits, phenol and flavonoids of stevia under field and greenhouse growth conditions were done during ۲۰۲۰-۲۰۲۱. In the field, plants were cultivated in five rows of ۱۰ plants in each, and at the same time ۲۰ potted plants were transferred into greenhouse with controlled temperature and humidity. Irrigation in the field treatment was drip. Greenhouse temperature between ۲۵-۳۰ degrees and humidity of ۷۰ percent was set. The results of comparison of cultivation of this plant under field and greenhouse conditions showed that in field treatment, the highest mean values shoot height (۶۷.۷۵ cm), number of leaves (۹۶.۸), fresh weight of leaves and stems (۰.۲۱۳ and ۱۵.۲۳ g) and dry weight of leaves and stems (۰.۰۶۰۷ and ۵.۵). The highest mean height (۳۸.۷۶ cm), number of leaves (۶۹.۲۵), fresh weight of leaves and stems (۰.۱۶۷ and ۵.۳۰۲ g) and dry weight of leaves and stems (۰.۰۱۹۸ and ۱.۵۹۰ g) were highest mean values in greenhouse treatment. On the other hand, in greenhouse treatment, the highest mean values of leaves phenol (۳۵۳.۰۴۳ mg/g FW) and flavonoids (۲۴۲.۴۱۲ mg/g FW) and in field treatment had the highest mean values of leaves phenol (۳۰۴.۶۵۲ mg/g FW) and flavonoids (۲۳۴.۴۱۲ mg/g FW). Generally, farm cultivation showed a positive effect on growth indices, and growing at greenhouse was favorable for accumulation of phenols and flavonoids in this valuable medicinal plant.

Keywords:

flavonoid , greenhouse , phenol , Stevia rebaudiana.