USE OF ESSENTIAL OILS AND EXTRACTS FROM SATUREJA AND ORIGANUM SPECIES AS SEED DISINFECTANTS AGAINST XANTHOMONAS AXONOPODIS PV. VESICATORIA (DOIDGE) DYE

The aim of this study was to test for antibacterial efficiacy and potential use as seed disinfectants of extracts and essential oils of Satureja hortensis, Satureja spicigera, Origanum onites and Origanum rotundifolium against Xanthomonas axonopodis pv. vesicatoria causes of bacterial leaf spot of pepper and tomato. According to the in-vitro test results, the essential oils showed a strong antibacterial activity based on the zone of inhibition against pathogen on Petri plates. The inhibasyon zones and MIC values of the essential oils ranged from 29-42 mm and 15.62-125 mu l/mL, respectively. However, the extracts showed weak or no antibacterial activity. According to the results on petri plate assays of O. rotindufolium and S. spicigera essential oils, some of the concentrations (31.25 and 62.50 mu L/mL) had toxic effect on the pepper seed germination, but the concentration of the oil with 15.62 mu L/mL had not toxic as compared to only the pathogen application. This application caused a decrease on the number of the infected seedlings with X. axanopodis pv. vesicatoria. Furthermore, this decrease was statistically significant compared to both streptomycin sulfate and only pathogen applications. On the other hand O. onites hexane extract had a toxic effect on the pepper seed germination, but all concentration of the acetone extract and chloroform extracts (except 20 mg/mL) had no toxicity. According to the results on pot assays, essential oils used in the best germination and disease control was observed at lower doses. In the application of the O. onites extracts onites the best germination and best disease control have changed according to the dose used. Our results showed that some of the concentrations of the essential oils and/or extracts from S. hortensis, S. spicigera, O. onites and O. rotindufolium can be used as a seed disinfectant and as potential control agents for management of the bacterial disease.