Improving the growth, yield and volatile oil content of Pelargonium graveolens L. Herit by foliar application with moringa leaf extract through motivating physiological and biochemical parameters

Recently, enhancing the growth and productivity of crops via biostimulants is a very imperative topic. It is so important for medicinal and aromatic plants to be produced by organic means in view of its therapeutic values. Among the nature plant growth promoters, moringa (Moringa oleifera, Lam.) has gained more attention. However, there are no elaborate reports on the impact of moringa leaf extract (MLE) as a growth promoter on medicinal and aromatic plants. Hence, the current report aimed to bridge this gap. This study was conducted to investigate the efficacy of MLE on the growth, biomass yield and volatile oil content of Pelargonium graveolens L Herit. Plants were foliar applied with MLE (v/v) at MLE1 (1:40), MLE2 (1:30), MLE3 (1:20) and MLE4 (1:10). Water spray was applied as a control. The obtained results revealed that plant height, branch number, leaf area, biomass yield and volatile oil content were significantly increased due to MLE application compared to untreated plants. Interestingly, not only volatile oil content but also the oil constituents were enhanced by MLE. The main constituents of volatile oil such as geraniol and citronellol were enhanced due to MLE application. Additionally, photosynthetic pigments (total chlorophyll and carotenoids), total phenolic contents, radical scavenging activity and nutrients of geranium leaves were improved due to MLE application. Among the MLE levels applied, 1:20 treatment was the most effective concentration in improving the investigated parameters. Conclusively, the current results suggested that MLE may be used effectively as a promise and a natural growth enhancer to improve the growth and productivity of geranium plant. (C) 2018 SAAB. Published by Elsevier B.V. All rights reserved.