Effect of 24-Epibrassinolide on Growth, Photosynthesis, and Essential Oil Content of Pelargonium graveolens (L.) Herit

The effects of 24-epibrassinolide on growth, photosynthesis, chlorophyll content, carbohydrate fractions, and essential oil content of rose scented geranium (Pelargonium graveolens (L.) Herit) were investigated. Foliar application of 24-epibrassinolide at 0.5, 1, and 3 mu M concentrations substantially increased the growth. 24-epibrassinolide at all concentrations improved herbage yield as reflected in the increase of foliar biomass. Exogenous application of 24-epibrassinolide increased the rate of photosynthesis. Growth promotion was also associated with increased chlorophyll content and resulted in the accumulation of carbohydrate fractions. At 3-mu M concentration, 24-epibrassinolide increased the total content of essential oils. The quantitative analysis of geranium oil from the geranium plant treated with 3-mu M concentration revealed an increase in geraniol content and decrease in citronellol content. The present study demonstrates a positive impact of the new group of phytohormones on the performance of geranium plant, a highly valued aromatic plant.