Relative leaf chlorophyll content of two stevia (Stevia rebundiana Bertoni) varieties as affected by two substrates and an organic certified foliar fertilizer system

Abstract

Stevia is a relative new crop species for the EU and recently was approved as an alternative to sugar. It has been studied recently in the EU and it is very much accepted by the consumers based on significant increase shown in market demand. This study evaluates the Relative leaf chlorophyll content (RLCC) of two stevia (Stevia rebundiana Bertoni) varieties as affected by two substrates and an organic certified foliar fertilizer system. The specific results from this study have shown that the two varieties (OLGA vs AMBROSIA) and the two substrates (CONVENTIONAL vs. ORGANIC) used influenced the relative leaf chlorophyll content (RLCC) and that the foliar fertilizers also exerted a significant effect in some cases. These finding can be followed up, and when stevia leaves are selected, at the end of the growing season (from a follow up study) can be correlated with SPAD units. Also, the substrates influenced the amount of soil water available to plants. Follow up studies will assess the effect of the treatments used on yield and sugars (stebiosides) components.