Agronomic Performance and Nutrient Content of Stevia (Stevia rebaudiana Bertoni) in Different Semi-Arid Locations

Abstract

ABSTRACT Stevia (Stevia rebaudiana Bertoni) is a medicinal plant whose leaves are used as a natural sweetener. This study was carried out to determine the agronomic performances, yield, and macro-micronutrients in the leaves of the plant under semi-arid conditions. For this purpose, field experiments were conducted in four different locations (Kahta, Menderes, Hasancık and ADYÜTAYAM) of Adıyaman province which is located in the Southeastern Anatolia Region of Turkey. 0.5 ha of land was prepared for each location. Plots were created as three replicates and the seedlings were transplanted in 70 cm × 33 cm row distances. Plants were harvested 2 times in one growing season. Fresh and dry herb yields in the first harvest were measured as 13,949.5 and 3900.3 kg ha−1, respectively, and at the second harvest as 6923.5 and 1920.6 kg ha−1, respectively, from Menderes location. Something similar happened with regards to the ratio of leaves per plant. The K and Mn contents of leaves were not found to be statistically different. With regards to the macro and micro-nutrients measured in stevia leaves, N (2.29–3.40%) and P (0.20–0.31%), Zn (21.4–44.7 mg kg−1), Cu (13.8–34.5 mg kg−1) and Fe (204.1–446.9 mg kg−1) values were found to be statistically significant. These nutrients were affected by location and harvesting time. TSG, Reb A and Stevioside contents in stevia leaves were measured as 10.93%, 4.73% and 4.95%, respectively. The results are similar to the values specified for Criolla variety. Considering the data obtained from the study locations, it was observed that stevia can be grown easily in semi-arid conditions. It is also concluded that at least two harvests can be taken in semi-arid conditions.