Processing Methods and Key Technical Points for Licorice Seeds

In the process of planting licorice, because the seed coat of licorice seeds is hard and keratinous, the seeds have difficulty absorbing water and will not germinate without treatment, which has become a difficult problem in large-scale licorice cultivation. At present, the sulfuric acid seed dressing method, the warming and repeated soaking method, and the seed coat crushing method have achieved good results in treating licorice seeds.

1. Sulfuric acid treatment method: For each kilogram of clean seeds, use 20-30 milliliters of 80% sulfuric acid and stir evenly. After 4-7 hours of treatment, rinse thoroughly with clean water, but the treated seeds must be dried in the sun before use. The treatment time of the seeds is related to the temperature and the amount of acid added. With the same amount of acid, the treatment time is short when the temperature is high, and the treatment time is long when the temperature is low.

2. Warming and repeated soaking method: Soak the seeds in warm water at 60°C for 6-8 hours. At this time, most of the seeds are fully swollen with water and separate into layers from the seeds that have not absorbed water. The seeds that have not soaked open are at the bottom, and the soaked-open seeds are on top, but they do not float on the surface. They can be poured out with the water as the soaked-open seeds drift out. Repeat several times until all the soaked-open seeds have drifted out for later use; then put the seeds that have not soaked open into 100°C water and soak for 2 minutes, remove them, immediately put them into cold water to shock them, and then put them into 60°C water to soak for 2-4 hours. At this time, the seeds have been properly treated. Put them together with the seeds that drifted out, rinse off the mucilage with clean water, and they can be used as seeds for sowing.

3. Seed coat crushing method: Put licorice seeds on a stone roller mill, with a thickness of 3 cm, and turn the seeds while crushing. When crushing, pay attention to changes in the seed coat of the licorice seeds. When the crushed seed coat appears yellow-white, it is ready. Put the crushed seeds into warm water at 40°C and soak for 2-4 hours, then remove them and rinse off the mucilage with clean water before sowing.

The method of crushing licorice seeds with a rice milling machine is simple and easy to carry out, with low cost and no damage, but care must be taken to control the degree of crushing. If crushed too lightly, it will not achieve the purpose of breaking the seed coat, and the germination rate will be low; if crushed too heavily, the rate of broken seeds will increase, and seeds will be seriously wasted. Practice shows that with rapid feeding, crushing 3-4 times is appropriate, and it is sufficient when the seed surface has obvious damage or the seed coat breakage rate reaches more than 90%. Because the seed coat of licorice seeds is keratinous and hard, they have difficulty absorbing water, which affects seed germination and seedling emergence.