This study aimed to determine the composition andthe antifungal activity of the essential oils of Vaccinium myrtillus and Laurus nobilis plants. In the study, 22 components were identified in the essential oil of V. myrtillus, which represented 100% of the total essential oils. Accordingly, 1,8-cineole (41.07%), β-Linalool (12.72%), α-Pinene (12.17%) and Myrtenol (6.48%) were determined as the main components of the essential oil of V. myrtillus. The essential oil of L. nobilis consisted of 39 compounds and 1,8-cineole (50.68%), α-Terpinyl acetate (14.19%), 4-Terpinenol (4.07%) and α-Terpineol (2.90%) were determined as the main components, which represented 100% of the total essential oils. In the trials, doses of 0 (control) 1, 2, 4, 8 and 10 μL/petri dish were used. V. myrtillus essential oil inhibited mycelial growth in Sclerotinia sclerotiorum (Lib.), Alternaria solani, Fusarium oxysporum f. sp. radicis-lycopersici (Sacc.) W.C. Synder & H.N. Hans (FORL) and and Verticillium dahliae Kleb by 61.38%, 100%, 80.36% and 57.91% respectively. Bay laurel essential oil at 10 μL/petri dish dose inhibited the mycelial growth of A. solani, S. sclerotiorum, (FORL) by 100%, whereas it inhibited the mycelial growth in V. dahliae by 61.23%. Study results showed that V. myrtillus and L. nobilis essential oils have strong antifungal activities.

The present study was conducted with the aim of determining biological activities of the Salvia bracteata plant, activities such as its antioxidant, total phenolic, total flavonoid, allelopathic and antifungal effects. To this end, aboveground parts (flowers + shoots + leaves) of S. bracteata plants were collected in the province of K?r?ehir, Turkey, during the flowering stage in 2018. As a result of GC-MS analysis, 23 constituents were identified, representing 96.21% of the essential oil. The major compounds of essential oil were identified as ledol (24.12%), camphor (15.54%) and valencene (5.64%). In ethyl acetate, methanol and hexane extracts of S. bracteata, total phenolic content was found to be 104.63, 121.66 and 20.97 mg of GAE/g of extract, respectively, while flavonoid content was 12.89, 10.85 and 1.13 mg of QE/g of extract, respectively. In addition to this, DPPH radical removal activity was identified and found to be at its highest in the methanol and ethyl acetate extracts. The TEAC (cation radical removal activity), FRAP (iron reduction power) and CUPRAC (copper reduction power) reduction activities of these plant extracts were also determined. The methanol extract of S. bracteata was found to have an allelopathic effect on Rumex crispus and Taraxacum officinale. This extract had a weak effect on development of the mycelium of Alternaria solani Sorauer, one of the most significant of plant-pathogenic fungi, but it was found to be ineffective on the Sclerotinia sclerotiorum pathogen.

The purpose of this study was to assess the effectiveness of essential plant oils from Vitex agnus-castus L. (VAC) and Myrtus communis L. against the plant pathogens, Fusarium oxysporum f. sp. radicis-lycopersici (Sacc.) W.C. Synder & H.N. Hans, Rhizoctonia solani J.G. Kühn., Sclerotinia sclerotiorum (Lib.) de Bary and Verticillium dahliae Kleb., and to determine the chemical composition of the compounds in these essential oils. GC/MS analysis was identified 25 different compounds in VAC essential oil, while the main compounds were determined as Eucalyptol (17.75%), β-Caryophyllene (13.21%) and Spathulenol (10.41%). On the other hand, the essential oil of M. communis, consisted of 16 different compounds which were Eucalyptol (49.15%), Myrtenol (19.49%) and α-Pinene (8.38%) being its main compounds. An assessment of antifungal activity was performed under in vitro conditions. Plant pathogens were inoculated onto Petri dishes (60 mm) containing PDA medium (10 mL/Petri-1), and plant essential oils were applied at concentrations of 0.5, 1, 1.5, 2, 5 and 10 (μL/Petri-1) into the 5 mm diameter wells opened on the Petri dish surface. After that, the Petri dishes incubated at 22±2 °C. The results of this study, the essential oil of M. communis, at a dose of 10 μL/ Petri, inhibited the 100% mycelium growth of V. dahliae, S. sclerotiorum and R. solani. The highest dose of VAC essential oil was also 100% inhibited V. dahliae and S. sclerotiorum. The LC50 and LC90 values of M. communis and VAC essential oil calculated for V. dahliae, FORL, S. sclerotiorum and R. solani. This plant extracts were shown by in vitro conditions to be potential antifungal agents.

In this study, chemical composition and allelopathic effect of essential oil obtained from ground parts (shoots+leaves+flowers) of Origanum onites L. plant on seed germination and seedling growth of different plant species were investigated. Essential oil was obtained with the use of the hydro-distillation method from O. onites plant collected from Mersin province. It was identified 24 different compounds by GC/MS analysis in O. onites essential oil, while the main compounds were determined as carvacrol (59.87%), γ-terpinene (17.08%) and β-cymene (8.83%). The allelopathic effect of the essential oil, two layers of filter paper were placed bottom of 9 cm diameter disposable Petri dishes then seeds of Amaranthus retroflexus L., Triticum aestivum L. and Lepidium sativum L. were homogeneously distributed on filter paper. Filter papers were thoroughly moistened using distilled water. The filter paper was glued to the center of the lid of each Petri dish. The different concentrations (0, 0.5, 1, 1.5, 5, 15 μl/Petri dishes) of the essential oil were applied to the filter paper pieces. Then lid of each Petri dish was closed and sealed with Parafilm. Petri dishes were incubation at 12 h dark-12 h light periods with an average temperature of 24±1 oC for 1-4 weeks. At the end of incubation period, germination rates, root and shoot lengths of the test plants were determined. The 15 μl/Petri concentration of O. onites essential oil were completely inhibited seed germination, root and shoot growth of A. retroflexus L., T. aestivum L. and L. sativum L. plants. A. retroflexus L. was found to be more sensitive to essential oil. The results show that O. onites essential oil has potential to be used in the control of A. retroflexus L., which has high allelopathic effect on seed germination and seedling development of L. sativum L., T. aestivum L., A. retroflexus L.