Key points of sowing and raising seedlings in broccoli cultivation

At present, the seeds of exported broccoli varieties are imported from abroad, with high price, extensive sowing, low emergence rate, large seed consumption and waste of seeds. Accurate sowing should be advocated to improve the sowing quality. The main measures: ① sowing and raising seedlings under the condition of protecting the environment (greenhouse or small arch shed). When sowing in summer, shading and cooling and preventing heavy rain, sowing and raising seedlings in winter and spring, electric heating or plastic greenhouse should be used to keep warm. After sowing, it is required to keep 20: 25 ℃ to ensure neat emergence of seedlings. Nutrient soil or seedling substrate should be prepared before ② sowing. ③ sowing density, 10 grams of seeds need about 3 square meters of sowing bed or seedling plate 4 plates, should not be too dense to prevent the production of tall seedlings. For ④ seed treatment, seeds without seed coat can be timely mixed with 50% thiram of 0.4% seed weight or 2.5% of 0.8% seed weight.

The main results are as follows: (1) Seedling raising methods: at present, broccoli seedlings are generally raised in fields, burrow plates or plastic bowls and nutrient solutions.

① field seedling: the seedling stage of broccoli is short, and the seedling bed is selected in the fields with high terrain, convenient drainage and irrigation, soil rich in organic matter, no cruciferous vegetables or rice in the past two years, and the direction of the seedling bed should be north-south. 15-20 days before sowing, 15 kg of compound fertilizer plus 5 kg of superphosphate per mu or 2500 kg of rotten acquaintance feces and urine were applied 7-10 days before sowing to ensure the full supply of nutrients at seedling stage. Before sowing, the seedling bed was watered once, and 1000 times phoxim and other pesticides were applied to prevent underground pests. When sowing, mix the treated seeds with an appropriate amount of sand and spread them evenly in the seedbed, suppress them with a shovel after sowing, and then sprinkle a layer of medicinal soil mixed with 0.1% carbendazim and dimethazone. After laying a layer of sunshade net in summer, set up a small arch shed, and then cover a layer of sunshade net for double-layer sunshade, moisturizing and cooling seedlings; in winter and spring, a layer of plastic film and a layer of greenhouse film were used to cover the heat preservation seedlings.

② pots or nutrition bowls: at present, there are mainly three kinds of hole trays (24cm × 60cm per plate) with 72,100,128holes, and the caliber of nutrition bowl is 5.0cm and 6.5cm. The nutrient soil can be prepared with 70% of the screened vegetable garden soil, 30% of the mature organic fertilizer, and 2% of the superphosphate (or rice chaff ash 1, mature organic fertilizer 1, and sifted vegetable garden soil 1, 3, plus compound fertilizer 4 kg / m3), which have not been planted in two years. Before sowing, the soil is thoroughly watered with appropriate amount of carbendazim, dimethazone, octylthiocarbamate and other pesticides. When sowing, sow the treated seeds into a hole plate or nutrition bowl or sow them into a seedling tray, then cover the sunshade net or greenhouse film, and raise seedlings in the same way as in the field.

Raising seedlings with ③ nutrient solution is a good way to raise seedlings at present, which has the characteristics of low cost, convenient management, high seedling rate and centralized seedling supply, so it is welcomed by production and processing enterprises. ① matrix: vermiculite 25%, peat 65%, perlite 10%. ② substrate stack disinfection: after fully mixing all raw materials, use 50% formalin (40% formaldehyde), spray evenly on the substrate, then cover tightly with plastic film, after 4 days of sealing, uncover the film for ventilation, and turn over the nutrient soil to volatilize formaldehyde, which can be used after 2 weeks. And need to adjust the pH of the matrix to 6.5-7, over-acid, with lime adjustment; over-alkali, can be neutralized with dilute hydrochloric acid. ③ sowing: fill the hole plate with substrate and pour water thoroughly, then dig the seeding hole with a special burrowing machine, sow the seeds into the sowing hole with the seeder and cover the substrate. Other seedlings are raised with the same acupoint plate or nutrition bowl.