How to raise watermelon seedlings in greenhouse, what technical knowledge do you need to master?

Seedling raising of watermelon in greenhouse is one of the key links in the process of watermelon planting and plays a key role in the yield of watermelon. Therefore, farmers must understand and master the relevant technical knowledge of watermelon seedling raising in greenhouse. This paper introduces this in detail, hoping to help farmers.

1, build a seedling shed

Because of the low temperature in winter, the management of seedling shed needs to be carried out day and night, so the seedling shed should be chosen in a sunny place around the village near home. The area of the seedling shed is determined by the number of seedlings, and the structure of the shed is the same as that of the general shed. In winter, the sunshine is short, cloudy and the temperature is low, so the temperature rise is mainly controlled by the furnace. Nursery has a large area and consumes a lot of energy. In order to save energy, the area of nursery should be appropriate and the direction should be east-west.

2. Build a heating furnace

Two heating furnaces were built. One is in the west of the shed, with the north-south direction as the center; The chimney is made of white iron with fast heat dissipation, and its diameter is between 15~20cm, and its length is equivalent to the length of the shed, showing an east-west trend, passing through the center of the shed, 80~ 100cm away from the ground, and gradually increasing near the chimney mouth, about 2m away from the ground. The chimney mouth is located on the east wall. The other stove is located near the southeast corner of the shed, and the chimney is from south to north. The chimney mouth is also located on the Dongshan wall, about 1m above the ground, and slightly higher near the exit. The suitable temperature for seed germination is 28~30℃. If the temperature is too low during the day, control the furnace at a suitable temperature.

3. Preparation of nutrient soil

Generally, high-quality decomposed organic fertilizer is used to mix soil, and compound fertilizer can also be added appropriately, and the dosage is 0.5 ~10.0 kg per 1000 plant. Don't use nitrogen fertilizer, add appropriate pesticides and mix well. The nutrition barrel has a diameter of 7cm, a height of 10cm and no bottom. Put the nutrient soil into a bucket, fill it to 8cm (leaving a space of 2cm), arrange it in an east-west belt with a width of 1.2 ~ 1.5 m, and ridging. The nutrition bucket can't be discharged at the width of about 80cm under the chimney to prevent the seedlings from baking, so it should be ridged.

Step 4: Sowing.

Seeds are treated with variable temperature to enhance stress resistance. In order to enhance the cold resistance of watermelon seedlings and promote their growth and development, germination seeds were alternately treated with high and low temperatures. The germinated seeds were placed at -2~0℃ for 15 ~ 18 hours, and then at 18~22℃ for 12 ~ 15 hours. During exercise, we should pay attention to keep the cloth of germinated seeds moist to avoid dehydration and dryness of the seeds. When the buds grow to 0.5 cm, they should be planted in the seedling tray. The sowing date should be 60 ~ 70 days before beginning of spring, that is, between light snow and heavy snow. When sowing, evenly wet and seep water, sow 1 gourd seeds in the barrel, and then cover the soil to the flat mouth of the nutrition barrel. Gourd seeds were sown earlier or at the same time than watermelon seeds 1 ~ 2 days. Sow watermelon seeds in a sand bed, and the sand-soil ratio is 1: 1. Add a proper amount of pesticides and fungicides and mix well. After wetting the frame, cover it with fine sand and then cover it with plastic film.

5. Transplantation method

Generally, the leaves of cucurbit are grafted at 1 and 1. The earlier the watermelon is grafted after emergence, the higher the survival rate. Combined with the weather forecast, choose sunny grafting. Water the day before grafting and cover with film. After sunrise the next day, dew on the film can provide shade, and then cover the flowers with grass in the greenhouse. When grafting, the greenhouse is kept at high temperature and humidity.

Within 4 ~ 5 days after grafting, it is kept at 30~36℃ during the day and above 20℃ at night. When the sunshine is insufficient, it is cloudy or the outdoor temperature is low, you must start a stove, add coal day and night, and don't stop the furnace. Generally, adding coal twice at 20: 00 pm and 02: 00 am can be controlled above 20℃.

6. Post-grafting management

Before grafting, the rootstock and seedbed should be watered for 65,438+0 times to make the seedbed saturated with water. Pay attention to heat preservation and shading for 3 days before grafting. The temperature of seedbed is controlled at 26 ~ 28℃ during the day, not lower than 20℃ at night, and the relative humidity is 65,438+000%. After 3 days, the seedlings should be exposed to visible light and gradually ventilated to see the light. Ventilation is needed after grafting, generally at 65,438. Ventilation should also be insisted on on cloudy days, and the heart with 3 leaves 1 should be ventilated day and night. After the grafted seedlings survive, the sprout of the rootstock should be wiped in time, and when the third true leaf appears, it can be transplanted and planted.

7. Wipe the gourd fork to prevent infection

After grafting survives, the melon forks are often separated and should be erased in time under suitable conditions. Choose a sunny morning. When the temperature is high, wash your hands first and keep them clean before wiping. Low temperature is not conducive to healing, and cold weather should be avoided. Unclean hands, sludge and dirty water on the wound, causing infection and tissue decay near the wound. Most of these seedlings grow into weak seedlings and cannot be used. Therefore, in the process of management, you can't wipe your crotch as soon as you find it. After washing your hands, you must wipe them on a sunny and hot morning.

8. Transplanting seedlings to promote branching and cultivate strong seedlings.

Transplant the grafted seedlings when they grow to 3 leaves 1 heart. Choose sunny days, move the nutrition barrels, and appropriately increase the spacing between the seedling barrels according to the seedling potential. Move the big seedlings to a cold place to inhibit their growth rate; Move the seedlings to a higher temperature to accelerate their growth. When moving the bucket, the root system growing to the bottom of the bucket is torn or injured, so the temperature must be kept above 30℃ during the day and above 20℃ at night within 1 ~ 2 days to facilitate wound healing. When the seedlings are short of water, water them. After moving the bucket, the top advantage is weakened, the lateral bud differentiation is accelerated, and the seedling spacing is large, which is beneficial to cultivate strong seedlings. Branching is the basis of increasing yield, because after transplanting into greenhouse, the temperature is high, the growth is fast, the differentiation of side branches is less, and the growth of single branch will seriously affect the yield.

9. Bake seedlings

When baking seedlings in the later stage, the higher the temperature during the day, the better, and control it at 8~ 10℃ at night. Strengthen ventilation and increase temperature difference to adapt to the climate after transplanting. Generally, transplanting is carried out at the time of 4 leaves 1.

10, pest control

The main diseases are Fusarium wilt, anthracnose and Fusarium wilt. Control methods: Fusarium wilt can be sprayed with 500 times of 50% carbendazim wettable powder, anthracnose with 5% chlorothalonil powder and Fusarium wilt with 600 times of 70% mancozeb wettable powder; The main pests are whitefly, aphid and liriomyza sativae, which are controlled by 25% chlorpyrifos 2000 times, once purified 2500 times and 10% beta-cypermethrin 2000 times respectively.

1 1. Strengthen the management of disastrous weather rooms.

Management in cloudy weather, rain and snow, strong cold current and other bad weather is an important link in the success or failure of seedling raising. Pay attention to the weather forecast and take warm measures before the cold current comes. In rainy and snowy days, it is necessary to cover the grass with two films. When it is cloudy, increase the light as much as possible without freezing. If the bed temperature drops after the cover is uncovered, the grass should be uncovered before 15: 00 pm. If the bed temperature drops slightly, it can be removed with a cover. Don't leave the film uncovered for several days. When it rains and snows, cover it with plastic film when the rain and snow stop. If the light is insufficient for a long time, fluorescent lamps can be used for artificial lighting. Uncovering the cover should be done slowly after a long period of cloudy and sunny days, otherwise it is easy to cause seedling flashing or even seedling falling. If it is found that the seedlings are wilting, they should be covered immediately and uncovered after the seedlings return to normal. Repeat several times until it does not wither.