Foliar spray of Moringa oleifera Lam. leaf extracts (MLE) enhances the stevioside, zeatin and mineral contents in Stevia rebaudiana Betoni

Moringa oleifera Lam., (family: Moringaceae) has begun to gain more popularity as a new ‘superfood’ due to its high nutritive value. It has been used for generations to treat and prevent the diseases such as diabetes, anemia, arthritis, and respiratory, skin, heart, liver and digestive disorders. Apart from these pharmacological activities, it is also a plant growth enhancer. The present work deals with a comparative assessment of the effect of foliar spray of Moringa leaf extracts (MLEs) of different varieties (PKM-1, PKM-2, Jaffna, ODC and Conventional) on the stevioside and mineral contents of Stevia rebaudiana Bertoni, a commercial natural sweetener plant. The decreasing order of stevioside and zeatin content in stevia plants after MLEs foliar spray, as determined by High Performance Liquid Chromatography (HPLC) was: Jaffna (7.73%; 0.0063%) > PKM-1 (6.93%; 0.0056%) > PKM-2 (6.45%; 0.0051%) > ODC (4.14%; 0.0048%) > Conventional (3.86%; 0.0042%) > Control (2.94%; 0.00088%) respectively. While, the decreasing order of mineral contents as determined by flame photometer was: Jaffna > PKM-1> PKM-2 > ODC > Conventional > Control. The comparative study revealed that among all the varieties, Jaffna significantly improved the growth and physiochemical parameters of stevia plants. Thus, this variety can be used as an eco-friendly and cost-effective plant growth enhancer in stevia farming and can be used for other commercially important crops.