Detailed Explanation of Key Techniques for Licorice Seed Treatment

Licorice seeds begin to germinate at 10-15°C, and germinate fastest at 15-20°C. The germination rate of old seeds decreases. One of the greatest characteristics of licorice is that it exhibits hard seediness, with the hard seed rate usually between 70-90%, making it very difficult for seedlings to emerge after sowing. Therefore, when propagating by seed in production, treatment before sowing is essential. The general treatment methods include the following:

(1) soaking seeds in boiling water; (2) soaking seeds in concentrated sulfuric acid; (3) grinding with crushed glass; (4) milling with a rice mill. Among these, milling with a rice mill gives the best results. Generally, a few days before sowing, use a rice mill to mill the seeds 1-2 times, until the seeds are seen to be scratched, but the seed coat must not be broken. Note that seed treatment must be carried out a few days before sowing; treating too early affects the germination rate. If the seeds purchased have already been treated and it is unknown how long ago they were treated, or if the surface shows signs of insects or mosquitoes, it is best not to use such seeds, because the germination rate is low.