Soak the seeds with warm scalding, keep the water temperature at 54 ℃ and soak the seeds for 30 minutes, and stir while soaking; Soaking seeds in cold water at a temperature of 10-15 ℃ for 6-8 hours; Constant temperature seed soaking, the temperature used is 25 ℃ - 30 ℃, and the seeds need to be soaked for 2 hours; Precautions: the seeds are not easy to soak and sprout too long, otherwise they are easy to be broken.
1. Warm scalding and seed soaking
Using the warm scalding seed soaking method, the germination speed of seeds is fast. Keep the water temperature at 54 ° C to soak the seeds for 30 minutes, stir them while soaking. After natural cooling, soak the seeds for about 2 hours. The soaking time should not be too long. Too long soaking will cause the seeds to crack and affect the germination.
2. Seed soaking in cold water
The cold water seed soaking method is usually used at a suitable temperature of 10-15 ℃, and the seeds need to be soaked for 6-8 hours. The time for soaking the seeds is different due to the size of the seeds and the thickness of the seed skin. Watermelon seeds with small seeds and thin seed skin can be selected for seed soaking, so the time for soaking the seeds can be effectively shortened.
3. Constant temperature seed soaking
The constant temperature soaking method is usually used. The suitable temperature is 25 ℃ - 30 ℃, and the seeds can be soaked for two hours under constant temperature. After the soaking of seeds, the seeds need to be placed in clean water and repeatedly kneaded and washed until the adhesive substances on the outer surface of watermelon seeds are removed, which is conducive to the germination of seeds.
4. Precautions:
The soaking temperature should be kept constant, and it can not be high or low. The most suitable soaking temperature is 33 ℃. It is not easy for the seeds to soak and sprout for too long, or they will be broken easily. Put the sprouted seeds on the wet cloth and sow them together when all the seeds are out. If the local temperature is too high during germination, it will lead to rotten buds during seed fermentation.
