High-yield cultivation techniques of Watermelon in Solar greenhouse (part I)

1. Variety selection

Jingxin Watermelon, Jingfeng No. 1, Jingfeng No. 2, Zaojia (8424), etc. It is characterized by disease resistance, low temperature tolerance, weak light resistance, good quality and high yield.

2. Grafting and raising seedlings

(1) making seedbed

Set up a bed or electric hotbed in the greenhouse, watermelons per mu should be 1.2 meters wide, 10 centimeters deep and 7 meters long, and the nutrition bowl containing nutritious soil 10 centimeters × 10 centimeters should be closely placed into the seedbed. The nutritious soil is made of mature organic fertilizer and fertile vegetable garden soil according to the ratio of 1 ∶ 3. Pour enough bottom water and cover with plastic film to increase temperature.

(2) soaking seeds to accelerate germination

The seeds of rootstock (calabash) were soaked in 70 ℃ hot water, stirred and cooled to 30 ℃, soaked in constant temperature for 6 hours, and germinated under the condition of 25 ℃ ~ 30 ℃. The sowing rate of scion (watermelon) was 75g / mu, sterilized with 55 ℃ warm water, stirred and cooled to 30 ℃, soaked in constant temperature for 6 hours, then kept moist at 30 ℃, and germinated for 12 hours under dark conditions.

(3) sowing

Watermelons in solar greenhouse are usually sown and raised in early December. In the method of using gourd as rootstock, the rootstock and watermelon scion should be sowed at the wrong time. 4-5 days after sowing, the watermelon seeds were soaked and germinated. Sow into a nutrition bowl when the radicle grows to 0.2cm and 0.5cm, and the soil is 1.5 cm thick. After sowing, the temperature of seedling bed is 25 ℃ ~ 30 ℃ in daytime and more than 15 ℃ at night. The seedlings can emerge after 7-8 days. When the melon seedling grows to 5 cm, it is sprayed with water and insecticide. 1-2 days after emergence, the cotyledons are grafted when the cotyledons unfold.

(4) Management after grafting

Shading, heat preservation and moisturizing within 3-4 days after grafting, temperature 26 ℃ ~ 28 ℃ during the day, 15 ℃ ~ 18 ℃ at night, relative humidity more than 90%, spray at noon if necessary; gradually increase light transmittance and ventilation to cool down after 3 days, shading at noon, temperature controlled at 22 ℃ ~ 25 ℃ during the day and 18 ℃ ~ 20 ℃ at night. To prevent excessive temperature, lack of light, resulting in excessive growth of seedlings. Especially when the first true leaf is expanded to the fourth true leaf, the ventilation rate should be increased and the temperature difference between day and night should be kept above 10 ℃ to ensure the normal differentiation of flower buds.

3. Colonization

(1) applying basic fertilizer for land preparation

The soil was raked deeply and ditched at a row spacing of 1 meter. 3000 kg of high quality farm manure, 50 kg of superphosphate, 10 kg of potassium sulfate and 10 kg of ammonium sulfate were applied in the ditch to mix manure and soil evenly. Then trench from both sides to cultivate a ridge with a width of 50 cm, a width of 35 cm and a height of 10 cm, leveling the ridge and covering the plastic film can be planted.

(2) colonization method

Choose a good day for planting in the morning. According to the plant distance of 50 cm, open the plastic film at the cross in the middle of the ridge, pull it on four sides, pour fixed planting water with shovel holes, plant seedlings with water, cover the soil after water infiltration and pull the plastic film back to the original place, and seal the gap with wet soil.