Triacontanol  Triacontanol can promote the growth of Laminaria pseudoroots, increase the fixation force, reduce seedling removal, improve the light and speed, increase the accumulation of dry matter, and increase the length, width, thickness and drying rate of Laminaria. Generally, soaking with Triacontanol can increase production in the period before and after the Laminaria seedbed leaves the warehouse (1~3cm), the temporary breeding period (3~20cm), the seedling dividing and clamping period (15~20cm) and the seedling clamping and stocking period (more than 20cm). The treatment method is: generally soak the seedlings with 0.5mg/L drug solution for 12h, Soaking seedlings for 10h at 1.0mg/L and 2h at 2.0mg/L is the best. It can also be used in 2-3 times. Soak it with 1mg/L for 6h one day before delivery, and then soak it with 1mg/L for 6h in the temporary curing period. It can also be soaked with 0.5-2.0mg/L solution for 1-3 times in the temporary curing period of seedling curtain, 2-12h each time.