EFFECT OF NUTRIENT LEVELS ON THE DITERPINOID GLYCOSIDES IN STEVIA (STEVIA REBAUDIANA BERTONI)

摘要

Field experiment was conducted at Water Management Research Center, Belavatagi (Dist: Dharwad, Karnataka) in medium black soil under irrigated conditions to assess the effect of different nutrient levels on the glycoside content of stevia. The resultsrevealed that higher stevioside and rebaudioside content was obtained in first and fifth cuttings, whereas die content was lower in third and seventh cutting. In fifth cutting nitrogen level of 80 kg/ha/cutting recorded stevioside concentration of 10.66% and rebaudioside content of 5.28% respectively followed by nitrogen level of 60 kg/ha/cutting (9.88 and 5.2%, respectively). Higher levels ofN, P and K resulted in higher stevioside and rebaudioside yield. Absolute control widiout any nutrients resulted in the lowest content of stevioside (8.59%) and rebaudioside (3.87%). Nutrient dose of80:60:40 kg/ha/cutting NPK ha~(-1) recorded the highest stevioside yield (332 kg ha~(-1)) and rebaudioside yield (158.2 kg ha~(-1))- The lowest stevioside yield (209.7 kg ha‘‘) and rebaudioside yields (202.9 kg ha'') were with the nutrient level of40:20:20 kg/ha/cutting NPK ha~(-1).