Breaking seed dormancy in oil rose (Rosa damascena Mill.) by microbial inoculation

This study was carried out to determine the effects of microbial inoculation in breaking seed dormancy and on the germination of Rosa damascena Mill. Seeds of R. damascena Mill. are the most used scented rose species in rose oil production. The most important production centers around the world are Turkey and Bulgaria. The seeds were subjected to 4 weeks of warm stratification at 25 degrees C, followed by 150 days of cold stratification at 4 +/- 1 degrees C. Before stratification, 4 different microbial fertilizers, EM.1 (R), B:speel (TM), Bioplin (TM) and Phosfert (TM) were inoculated to the seeds. In the study, the microbial inoculation treatments significantly (p < 0.01) promoted the premature germination percentage during cold stratification. During the stratification, the highest premature germination percentage was obtained from the EM.1 (R) (69.3%). The highest germination percentage in terms of cumulative germination percentage was determined in EM.1 (R) (100.0%), followed by Phosfert (TM) (84.0%) and B: seepel (TM) (84.0%), whereas the lowest germination percentage was found in the control treatment (69.3%). The EM.1 (R) shortened the mean germination time by 1.7 days in comparison to the control. In conclusion, it was observed that with microbial inoculation (particularly EM.1 (R)) to oil rose seeds and a stratification time of 150 days, dormancy was broken and germination highly improved.