Antifungal activity of Citronella essential oil against stem-end rot of mango

Abstract: Stem-end rot caused by Diplodia natalensis is one of the significant postharvest diseases causing setbacks in the mango industry. Essential oil shows excellent potential as an alternative method in controlling postharvest diseases, which are considered safe and biodegradable with no residual effect. Hence, the study was conducted to determine the antifungal activity of Citronella essential oil against Diplodia natalensis (Pole Evans), to identify the effective concentration of Citronella essential oil to control D. natalensis in vitro and to evaluate the potential of citronella oil as treatment against stem-end rot disease of mango fruit. Results showed that citronella oil at 30% - 80% concentration exhibits fungistatic activity. At the same time, Citronella at 90% concentration showed fungicidal activity, which was most effective, showing complete inhibition of mycelial growth in the in vitro experiment. Furthermore, a significant reduction in fruit decay and percent fruit decay was noted with the 90% concentration of Citronella essential oil compared with the control in the in vivo experiment. However, no significant differences were observed between treatments regarding the length of exposure at 90% concentration of the essential oil. These results suggest that Citronella essential oil can potentially control stem-end rot in mangoes.