Effects of ZnSO4 Foliar Application on Vegetative Growth and Phenolic and Essential Oil Content of Geranium (Pelargonium odoratissimum L.)

Pelargonium odoratissimum is a perennial evergreen used as a fragrant ornamental plant. Leaves, green branches and fresh flowers contain essential oils, that have been shown to possess antibacterial, antifungal, antiviral, insecticidal and antioxidant properties. In order to study the effect of foliar spray of ZnSO4 (0, 1000, 2000, 3000 and 4000 mg L-1) on vegetative growth and some physiological characteristics of Pelargonium odoratissimum L. plants, a pot experiment was carried out during 2015 at the Research Greenhouse of Azarbaijan Shahid Madani University, Iran. Vegetative growth (plant height, fresh and dry weight) was significantly affected by the application of ZnSO4. Foliar application of ZnSO4 promoted plant height especially at 2000 mg L-1. Chlorophyll a, b, total chlorophyll and carotenoid contents were affected with ZnSO4 treatment as well. The content of essential oil was not significantly influenced with ZnSO4 spray. ZnSO4 application had significant effect on total phenolic and anthocyanins (at 1000 and 2000  mg L-1) and total flavonoids (at 2000 mg L-1) content.