The effects of different pre-sowing seed treatments on breaking the dormancy of mahaleb cherries, Prunus mahaleb L. seeds

Seeds of the mahaleb cherry, Prunus mahaleb L., used as a rootstock in cherry production, germinate and emerge poorly due to seed dormancy. A greenhouse experiment was done to determine the effects of several treatments to overcome this dormancy, i.e. prolonged (30, 60 and 90 days) stratification followed by hot water treatment at 90 degrees C (for 0, 10, 20 and 30 minutes) or sulfuric acid scarification (0, 10, 20 and 30 minutes) or gibberellic acid, GA(3) (0, 500, 1000 and 2000 ppm). The results showed that stratification for 60 days or more increased germination percentage and decreased mean germination time. Scarification with either hot water or sulfuric acid only improved germination percentage and speed if followed by 60 days of stratification. Treating the seeds with GA(3) resulted in a significantly higher germination rate. The highest germination percentages were attained by treating seeds which had been stratified for 60 and 90 day-periods with GA(3) at 1000 ppm. It is recommended that GA(3) should be used in addition to cold stratification for improving germination percentage and speed of mahaleb cherry seeds.