Plug seedling cultivation is a new seedling cultivation technology introduced from abroad. The seedling trays used in this method are divided into grids. When sowing, one seed is placed in each hole, and when the seedlings are grown, one plant is placed in each room. In the United States, Booth Speed ??Nursery Company and Lifespan Company in Florida, USA, use PLUG seedling technology. The seedling containers use TODD series polystyrene plates. There are many tapered holes in the plates, and the holes can be large or small. , generally a plug tray of 70 cm x 35 cm with holes at the bottom. The seedling trays are available in 13 specifications, suitable for different flowers. The substrate for raising seedlings is mainly peat and vermiculite, with perlite, bark and moisturizer added.
1. Seed treatment
To cultivate high-quality plug seedlings, first select seeds with full seeds, high viability, high germination rate and germination potential, and perform seed treatment. The methods are:
(1) Water soaking method
For seeds that are easy to germinate, such as redbud, pearl plum, weigela, etc., soak them in warm water at 40 to 60°C for 1 to 2 days. For direct sowing, torch tree and other seeds are soaked in hot water at 90°C and allowed to cool naturally for 24 hours to soften the gummy and waxy seed coats and absorb water before they germinate. However, the water immersion method requires frequent replacement of new water. The water temperature should not exceed 60°C for more than half an hour. After that, the water temperature should be lowered to below 40°C, otherwise the embryo will die easily.
(2) Low temperature method
Prickly pear, wintersweet, forsythia, lilac and some autumn sown grasses and flowers need to undergo a certain low temperature (0~10℃) treatment to break dormancy . That is, mix or layer the seeds with sand with a humidity of 60% (knead it into a ball with your hands and it will fall apart when touched), and then bury it in the sand 40 to 60 cm deep; you can also place the seeds in a refrigerator at 3 to 5°C for 60 to After 90 days, take out and sow in spring.
(3) Variable temperature method
For flowers with the habit of double dormancy of radicle and hypocotyl, such as fringe, peony, peony, and podworm, the radicle will take 1 to 2 months to 25 to At a high temperature of 30°C, the hypocotyl requires a low temperature of 3 to 5°C for 1 to 3 months to release dormancy. For these seeds, if they are mixed with wet sand before sowing, and then turn to low temperature after a certain period of high temperature, they will germinate quickly when sown in spring. After seed treatment, pelletization is carried out, that is, soluble glue and fillers, as well as substances that are beneficial to seed germination, are bonded to the surface of the seeds to make the surface of the seeds smooth, consistent in size and shape, the particle size becomes larger, and the weight increases. Especially the seeds of crab apples, petunias, cockscombs and other seeds with small particle size that are difficult to sow have good results.
2. Selection of seedling trays
The holes in the seedling trays have square cone shapes and cone shapes. Since the square cone has a large volume and can provide more nutrients and oxygen, both are used. Square cone hole. The plug trays must be cleaned and disinfected before sowing.
3. Tray loading and sowing
There are two types of plug sowing, mechanical and manual. Precision seeders are used for machinery, and manual sowing is generally used when the quantity is small. The substrate for seed sowing is generally culture soil. Do not fill the substrate too full. Press it down evenly with your hands, and carefully place the seeds into the hole trays, one seed in each hole, and then lightly cover with a layer of fine soil or sand. Level with the small grid, spray water in time after sowing until there is water oozing out from the bottom of the plug tray, then cover it with mulch to keep it warm and moisturizing.