There are two primary methods for cultivating Wakame (Undaria pinnatifida) seedlings: low-temperature seedling cultivation and normal-temperature seedling cultivation. The low-temperature method involves growing kelp seedlings in a controlled, cooler environment to promote the development of spore bodies. This technique requires specialized equipment, which leads to higher costs and more complex procedures, making it less commonly used today. In contrast, the room-temperature method is simpler and more practical. It only requires basic facilities such as a nursery room, a seawater sedimentation tank, a filtration tank, and a seeding applicator.
**Nursery Conditions**
1. The nursery should be located near the coast where seawater can be easily pumped in, ensuring a fresh supply of water and avoiding areas near estuaries.
2. The nursery room should be oriented east-west, with a skylight covering about one-third of the roof area and side windows taking up 1/3 to 1/4 of the wall space. A shading system should also be installed to control light exposure.
3. Seedling ponds can be either shallow kelp nursery belts or regular deep pools, depending on availability and resources.
4. A sedimentation pond is essential, accounting for about 50% of the water used for seedling cultivation. A filter pond should be approximately 1.5% of the total nursery pond size.
5. Seedlings are typically made from red-brown rope or braided net curtains, though polyethylene net curtains can also be used.
**Vegetable Selection and Stimulation**
1. Select healthy kelp with thick, fleshy leaves, large and soft texture, dark brown color, and visible spore bulges with mucus.
2. The recommended density is around 10 sporophyll leaves per square meter of nursery pond, or 100 grams of mature spore leaves per 100 meters of seedling lines.
3. To stimulate growth, the kelp is often dried using the overcast method. After being collected from the sea, it is rinsed with filtered seawater and hung in a well-ventilated room or placed on clean straw mats without crushing. It is then exposed to sunlight and allowed to dry.
**Suitable Picking Time**
The best time to harvest is when the natural seawater temperature rises to between 18°C and 23°C, ideally from mid-June to mid-July.
**Process Flow**
Stimulate vegetable growth → Disperse spores → Spore dispersal → Spore attachment → Control seedling density → Indoor cultivation → Temperature adjustment → Light control → Appropriate fertilization → Timely washing and water change → Seedling storage
**Fertilizer Application**
During the Wakame nursery period, nitrogen and phosphorus fertilizers should be applied. In the early stages of gametophyte and sporophyte development, the water should contain NO3-N at 4 ppm and PO4-P at 0.3 ppm. After the formation of sporophytes in mid-August, the concentration should increase to NO3-N at 5 ppm and PO4-P at 0.4 ppm. Fertilization is typically done after changing the water, and the fertilizer is usually sprayed evenly at a 5% concentration.
Medical Ultrasound Gel,Aquasonic Ultrasound Gel,Aquasonic Gel,Clear Ultrasound Gel
Suzhou Letai Medical Technology Co.,Ltd. , https://www.letaihealthcare.com