Essential oil compounds and pesticide residues of rose oil obtained with conventional and organic agriculture

In this study, rose oil composition and pesticide residues of conventionally or organically produced essential oils of oil-bearing rose (Rosa damascena Mill.) cultivated in Göller region of Turkey were compared. Essential oils obtained from oil bearing rose flowers were distilled under factory and laboratory conditions during the flowering season of 2018, weekly composition and pesticide analyzes were carried out on GC/MS (Gas chromatography/Mass spectrometer). Results showed that organically cultivated oil bearing roses contained lower amounts of essential oil than conventionally cultivated oil bearing roses. The highest essential oil ratios in both conventional and organic oil bearing rose flowers were obtained in the weeks, corresponding to the middle of the flowering season (3rd week of the season). In general, there was no significant difference in the composition of essential oils between organic and conventional rose oils, but citronellol + nerol and methyl eugenol ratios were higher in organic rose oils. It was found that cohobation rose oils, which was the 2nd distillation product, contained 10 times more methyl eugenol than the 1st distillation flower oils. In conventional rose oils, fungicide active compounds such as Fluopyram, Tebuconazole and Penconazole, insecticide active compounds such as Malathion, Thiacloprid, Cypermethrin, Dimethoate and Deltamethrin were found above the limit of quantification (LOQ) at 0.005 ppm. These active substances were not detected in the organic rose oils.