HYBRID EVENT: You can participate in person at Rome, Italy or Virtually from your home or work.
September 16-18, 2024 | Rome, Italy
GPMB 2023

Zenzile Khetsha

Zenzile Khetsha, Speaker at Botany Conference
Central University of Technology, South Africa
Title : Abscisic acid and methyl jasmonate concentration and application periods on the essential oil biosynthesis of simulated hail-damaged rose geranium (Pelargonium graveolens LHer. cv. Bourbon


Extreme abiotic stress factors such as hail, defoliation, salinity, and moisture stress can affect biosynthesis of essential oils. This study aimed to investigate the potential use of two plant stress hormones: abscisic acid (ABA) and methyl jasmonate (MeJA) on essential oil biosynthesis of simulated hail-damaged rose geranium (Pelargonium graveolens L’Hér.). The study was conducted in a 72m2 temperature-controlled greenhouse, using a 5 x 2 factorial treatment design, which was arranged in a randomized complete block design. Treatments comprised four levels of two plant stress hormones at 75 µM (ABA), 150 μM (ABA), 10 mM (MeJA), 20 mM (MeJA), and a control, applied in two different application periods (daily application for either seven or 14 days). The simulation of hail damage was through 100% defoliation, with the decapitation of the terminal buds. The results showed that using 10 mM (MeJA) for a shorter period (seven days) increased the recovery of the essential oil yield compared to the 14 days application period. Citronellol, geraniol and linalool were significantly affected by the application of the two plant stress hormones. Geraniol esters were partially improved by the application of MeJA at 10 mM. Citronellol to geraniol ratio, a determining factor of essential oil quality, was better when MeJA was applied compared to ABA. Application of MeJA at 10 mM may improve the essential oil biosynthesis of hail damaged rose geranium plants.

What will audience learn from your presentation?

  • This study assist conclusion showed that plant stress hormones in isolation improves some of the important essential oil compound linked to the perfumery industry; however, crucial compound declined significantly, although the quality was favored when one specific plant stress hormone was used.
  • Horticulture discipline may use the information for setting indexes on which plant stress hormones works better in isolation for selected stress factors.
  • Study proved that using sole synthetic plant stress hormone may be expensive and should be used with other synergistic plant growth hormones for better improvement of plants grown under stress state.


Zenzile Peter Khetsha is a senior lecturer in the Department of Agriculture, Central University of Technology, Free State. He obtained his Doctor Technologiae: Agriculture at Central University of Technology, Free State, followed by a Postgraduate Diploma in Higher Education (Rhodes University) and Postgraduate Diploma in Leadership Development (Stellenbosch University). He is a Certificated Natural Scientist with SACNASP and a recognised Fertilizer Advisor with FERTASA. His area of research focus is on the development of mitigating strategies for stressed aromatic & medicinal plants and has authored at least ten research articles since 2020.