Effects of Scarification and Temperature on Germination of Licorice (Glycyrrhiza glabra L.) Seeds.

Laboratory experiments were performed to determine the effect of various scarification treatments at four temperature regimes on germination of licorice seeds . A randomized complete block design with four replications was used. Germination counts were made every day for 2 weeks. At 50C, none of the chemically and mechanically scarified and non scarified seeds germinated. At 15, 25, and 350C, mechanical scarification increased seed germination to 94-98%. However, at these temperatures, velocity of germination of mechanically scarified seeds were lowest among all treatments. Chemical scarification also increased germination percentage significantly to 90-95% with 45 min soaking. At 15 and 250C, seed germination percentage and velocity of germination increased as the soaking time in sulfuric acid increased from 5 to 30, 45, or 60 min. However, at 350C, there was no difference in germination percentage between soaking times of 5 and 60 min. It appears that soaking for 45 min provides full germination at 25 and 350C.