How to raise nutritious porphyra? What are the key points of daily management?

Porphyra yezoensis is an important kind of economic bath, delicious and nutritious, in addition to edible, but also has the effect of disease prevention and treatment, but also an important raw material for the new Agar industry. The culture of Zilai has a short production cycle. The characteristics of simple production operation, no damage to feed, low production cost and high income are an important way for coastal areas to make full use of coastal tidal flat, develop production, get rid of poverty and become rich. How to raise Laver? What are the key points of daily management?

I. basic conditions

1 selection of sea area: the sediment of the sea area should be sandy and muddy, the beach surface is flat, the specific drop is small, and the flow rate is 10 cm / s-30 cm / s. The water quality is fresh and the salinity is 22 ‰-30 ‰. The plug-in cultivation should be at low tide level, and the subtidal zone is OK.

(2) Culture method: plug-in culture is generally adopted in Zhejiang area.

2. Aquaculture facilities

The plug culture method is mainly composed of the following:

1 net curtain: the net curtain is divided into mesh and strip network, the mesh is 2.0-18 meters long and 1.8-4.0 meters wide, and the mesh is not less than 25 cm, square or diamond; the strip net is 5 meters long, 4 meters wide and 7.5-8 cm apart.

2 Pole: made of 7-12 cm diameter pruning bamboo with a length of 7-12 m.

3 buoy: bubble plastic or bamboo.

4 cable: made of polyethylene, the length is more than 2 times the depth of the most exciting part of the aquaculture sea area.

5 float: made of silk polyethylene.

6 hanging rope: made of polyethylene with a length of 5-10 meters.

7 piles: made of iron anchor, wood or bamboo.

3. Seedling cultivation

The hanging of the seedling net should be carried out shortly before the tide, and the seedling net should be hung on the shelf with three layers of overlap. The seedling net hanging on the pontoon should be as flat and tight as possible. If the seedling net just hung up for a long time from the high tide, it can be sprayed with seawater to keep the seedling net moist. After the seedling net is hung, it needs to be inspected and managed every day, and the seedling net should not be loose or sagging too much. In the sea area with more floating mud, or when there are more algae on the seedling net, the net should be washed and dried in time. After 30-40 days of cultivation, the net line is covered with 1 cm ~ 3 cm seedlings, which can be cultivated separately or refrigerated with refrigerated net technology according to the need.

IV. Daily management

1. Seedling stage management

The stage of 8-15 days is the emergence stage, which mainly increases the emergence rate and promotes the early growth, fast growth, completeness and less seedling loss of young seedlings. Is the critical time of the year, should pay attention to strengthen management and responsibility, generally use the sea on the third day to wash the net, dry dew, to the net once every three days after drying to the emergence of complete, to keep the net free of miscellaneous algae, no sludge attachment, this period is encountered in October spring, high temperature should pay special attention to adjust the water layer to prevent seedling death.

two。 Thallus period management

The yield and quality of porphyra yezoensis culture mainly depend on whether the Thallus grows normally and the harvest time, and is related to the management level. Therefore, we should focus on the following links:

(1) promoting growth. After the seedlings have grown well, we should pay attention to adjust the water layer every day, dry dew time is not less than two hours, increase the photosynthesis time of Thallus, show the phenomenon of lack of fertilizer in the middle of the dense sea area, and properly spray urea.

(2) quality assurance. Improving the quality of dried porphyra is the key to increase production and income of porphyra. During the management period, attention should be paid to timely harvesting. Generally, porphyra yezoensis can be harvested for the first time when the Thallus grows to more than 20 cm, and then every 7-10 days, so as not to age the Thallus and keep the algae thin and soft.

(3) cutting and retention, in order to increase yield and income, the proportion of cutting and retention should be properly controlled in the first harvest of porphyra yezoensis, generally cutting out 1/2 of the Thallus.

V. Disease prevention

The main enemies of porphyra yezoensis during the growing period are plant moss, filamentous green algae, diatoms, etc., epiphytic to the net curtain, encroaching on the seedling position, fighting for nutrition, shading, mixed algae are difficult to distinguish, affecting the quality of dry products, and the animal species of class nematode fishes, goldfish, Niangai fish and other direct algophagous bodies are very harmful, pest removal methods, if small seedling epiphytic algae, can be exposed to strong light for 12 hours and then put down in the sea This kind of algae turns white and dies in water. The animal enemy damage is mainly in the open sea area, and the main removal methods are to drive, bomb and hang explosive bags. There are also bacterial green rot, due to high temperature, too dense water flow and other factors, so that the Thallus rot turns green, serious when the whole sea area rotten. Emergency measures: immediately adjust the water layer, sun the net for more than 20 hours and then put it back into the sea.

VI. Harvest

40-50 days after collecting shell spore seedlings, the leaves of porphyra yezoensis can be harvested for the first time when the leaves grow to 20-30 cm, and then every 15 days or so. It can be harvested about 12 times in the whole culture period.