The productivity of Stevia rebaudiana (Bertoni) on dry leaves and steviol glycosides of four varieties grown in six regions of Morocco

Abstract

Stevia rebaudiana Bertoni, is a perennial herbaceous plant native to Paraguay. This plant produces diterpene glycosides that are powerful natural low calorie sweeteners , about 300 times sweeter than saccharose. Stevia has now become an important agricultural crop for the production of a high-potency natural sweetener. Cultural practices are still in development and the productivity potential of desirable steviol glycosides in more or less stable proportions and under different agriculture conditions are largely unknown. Currently, commercial growers and processors all over the world are seeking to maximize the productivity of rebaudioside A , a steviol glycoside . The present study aimed to characterize the effects of region and varieties on stevia dry leaf yield, steviol glycoside content, and steviol glycoside yield under Moroccan conditions. The content of steviol glycosides obtained from dry leaves of four varieties of Stevia rebaudiana , compared to the edaphoclimatic conditions in six different areas in Morocco, was determined using High-Performance Liquid Chromatography (HPLC). Dry leaf yield, leaf steviol glycoside content, and leaf steviol glycoside yield varied according to varieties and regions, with significant interaction of varieties by regions. Dry leaf yield varied from 1.57 to 7.86 t/ha. Stevioside yield ranged from 57.04 to 739.77 kg/ha and rebaudioside A yield varied between 60.8 and 614.04 kg/ha, with Reb A/STV ratios that reached up to 2.62. The total of steviol glycosides yield ranged from 163.21 to 1353.2 kg/ha with significant interactions between regions and varieties concerning sweet glycoside contents. Stevia offers great potential for introduction as a commercial crop producing a biological sweetener under Moroccan conditions. • Rebaudiana crops have proved to be very well adapted to the Moroccan conditions. • High dried leaf yields of stevia were detected with significant variability. • The accumulation of steviol glycosides was very important in the 4 varieties. • Biomass and steviol glycosides are influenced by Variety × environment interactions.