Antimicrobial Activity of Some Essential Oils Against Agricultural Phytopathogenic Fungi and Bacteria

Özet

Essential oils (EOs) are gaining attention as eco-friendly alternatives to synthetic pesticides for the management of phytopathogenic fungi and bacteria. In this study the in vivo antimicrobial activities of Juniper (Juniperus communis), Rosemary (Rosmarinus officinalis), Cumin (Cuminum cyminum), Sage (Salvia officinalis), Dill (Anethum graveolens) and Oregano (Origanum onites) essential oils were investigated against 2 phytopathogenic fungi (Fusarium solani, Rhizoctonia solani) and 2 bacteria species (Erwinia caratovora, Streptomyces scabies) causing high economic losses in potato. Pot experiments were conducted in a completely randomized factorial design with three replicates at greenhouse conditions. EOs were sprayed at 0, 100, 250, 500 and 1000 µl/l concentrations to aerial parts of potato plants with a manually operated sprayer for 3 times at 15 days intervals starting from the 4-5 true leaf. The application of EOs showed low to high efficiency in suppressing fungal and bacterial diseases of potato tubers and the effectiveness of EOs applications varied depending on the application dose. The highest antifungal activity were obtained from juniper EO on F. solani and sage essential oil on R. solani. R. solani infection severity, which was 20.8% in the control, decreased below 4.3 % with 500 ppm and above sage EO application. Dill, oregano and rosemary EOs were more effective than other EOs in preventing bacterial infections. The infection severity of common scab, which was 16.4% in the control, decreased below 2% and 9% with 1000 ppm oregano and rosemary applications respectively.