Effect of different plant beds and fertilizers on Stevia (Stevia rebaudiana Bertoni) production

Abstract

Stevia rebaudiana Bertoni is well-known for its high content of steviol glycoside, a diterpene compound (about 4-20%) in dryleaf matter that is responsible for providing the non-caloric value sweet taste. Steviol glycosides are natural sugar substitutes for diabetics and other people on carbohydrate-controlled diets. Studies revealed that the glycosides yield, especially stevioside, greatly depends on the total biomass yield, which in turn depends on agricultural practices for cultivation of stevia. In this study, the effect of five various combinations of soil, cocopeat, perlite, and vermicompost plant beds mixed with four different fertilizers of tea compost, vermiwash, Hoagland and water, on four different physiological (leaf area, stem length, fresh weight and dry weight) and six different biochemical (chlorophyll content, carotenoid, protein, glucose, phenols and rebaudiosides) characteristics of plant were evaluated. To gain the highest content of biochemical compounds, especially all types of rebaudiosides, a combination of vermicompost, perlite and cocopeat with vermiwash or any other fertilizers can be useful.