The effects of essential oils obtained from different plants against plant pathogens

The pre-harvest period of the agricultural lands, plant pathogens are one of the most important factors that negatively affect the yield. It is known that synthetic chemical-based the chemical defense methods used to prevent bacterial or fungal diseases have side effects. It is often recommended to use natural ingredients instead of these chemicals. Based on this knowledge, in the present study, the antimicrobial effects of essential oils obtained from Satureja hortensis, Mentha longifolia belongs to Lamiaceae and Thuja orientalis of the Cupressaceae family were investigated against six different plant pathogens. It was determined that the essential oils of Satureja hortensis (MIC value 5µL/mL) showed significant activity against all tested organisms, while the essential oils of Mentha longifolia (MIC value 5-20µL/mL) and Thuja orientalis (MIC value 10-160µL/mL) showed low activity. A significant effects of Satureja hortensis essential oil were detected in the prevention and elimination of bacterial activities of essential oils in pepper seedlings. No significant physiological changes were observed in the chlorophyll a-b, total chlorophyll, and carotenoid contents. As a result, it was determined that the applied essential oils decreased the bacterial load in pepper seedlings, and could cause morphological changes but did not have significant effects on photosynthetic pigments.