Modeling stevia yields depending on plant density and mineral fertilizers rates

The world market of sugary products reaches 80 billion USD, as estimated for 2011. 82 percent of the global market is occupied by sugar from sugar-beets and sugarcane, 9 percents are represented by sugary syrups, and the remaining 9 per cents falls on other sugar-replacing substances, among which stevia (Stevia rebaudiana Bertoni) is the prevailing source of sweeteners. While in the early 2000s, stevia’s main consumer was Japan (estimated as 90% of the total consumption), nowadays the products prepared using stevia raw material are in high demand worldwide, including such huge consumers as the USA, PRC, Germany, Russian Federation, Egypt, Indonesia, etc. Stevia’s popularity is also increasing in Ukraine (Roik et al. 2015).