Foliar spray of moringa leaf extract improves growth and concentration of pigment, minerals and stevioside in stevia (Stevia rebaudiana Bertoni)

摘要

Moringa (Moringa oleifera L.) leaves are well recognized for their nutritive and pharmacological properties. Recent studies suggest that moringa leaf extract (MLE), owing to the higher concentration of hormones, amino acids as well as micro and macronutrients and other beneficial compounds may also be utilized as a potential plant growth enhancer. The present study reports the effect of foliar applied MLE concentrations (water spray as control, MLE at 10, 20, 30 %) on the growth and mineral content of Stevia rebaudiana. A significant increase in growth attributes, photosynthetic pigments and the soil plant analysis development (SPAD) value was recorded in MLE treated plants compared with control. Moreover, MLE treatment considerably increased the concentrations of macro and micro nutrients including N, P, K, Mg, Na, P, Zn, Fe and Ca in the leaves of the stevia plants. Moringa leaf extract (20 percent) resulted in the highest production, minerals, and nutraceutical-related characteristics in stevia plants as compared with other treatments. Moreover, stevioside contents were also increased with 20 % MLE spray. Traits association revealed that plant height had a significant association with growth attributes and SPAD value. Among minerals, N exhibited a significant relationship with other mineral nutrients. Likewise, total phenols showed a significant relationship with carotenoids, chlorophyll a, and chlorophyll b. Our findings provide evidence that foliar spray of MLE may be used to increase growth, biomass, stevioside, minerals and nutraceuticals in S. rebaudiana.