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 ۲ weeks. At ۵۰C, none of the chemically and mechanically scarified and non scarified seeds germinated. At ۱۵, ۲۵, and ۳۵۰C, mechanical scarification increased seed germination to ۹۴-۹۸%. However, at these temperatures, velocity of germination of mechanically scarified seeds were lowest among all treatments. Chemical scarification also increased germination percentage significantly to ۹۰-۹۵% with ۴۵ min soaking. At ۱۵ and ۲۵۰C, seed germination percentage and velocity of germination increased as the soaking time in sulfuric acid increased from ۵ to ۳۰, ۴۵, or ۶۰ min. However, at ۳۵۰C, there was no difference in germination percentage between soaking times of ۵ and ۶۰ min. It appears that soaking for ۴۵ min provides full germination at ۲۵ and ۳۵۰C.

Keywords:

Licorice dormancy , Weed biology , Weed seed germination