Technical points of raising seedlings of muskmelon in early spring

The nutrient soil is prepared by sieving and mixing fertilizer soil which has not been planted with melons and vegetables and chicken manure or manure which is fully fermented and decomposed according to the ratio of 7:3. 2.5kg calcium superphosphate, 0.5kg potassium sulfate and 15 - 20g 95% mefoprim are added into each cubic meter of nutrient soil. 24~26 square meters of seedbed should be built for each mu of field to build electric hotbed. The seedbed is 1~1.2 meters wide, 10~12 meters long and 12 centimeters high. The bottom of the bed is first paved with a layer of plastic film. The film is evenly sprinkled with dry wheat bran or sawdust with a thickness of 3 centimeters. The wheat bran is then paved with a layer of plastic film. The film is paved with clean coarse gravel with a thickness of 2 centimeters as an irrigation water layer. The top is covered with nutrient soil with a thickness of 10 centimeters. Then, irrigation is carried out. After water penetration, it is cut into pieces according to 10 centimeters square and electric heating lines are laid. The edge of the seedbed is paved every 10 cm wide, and the center is paved every 20 - 30 cm wide. After straightening, the seedbed is pressed into the slit of the seedbed, and the depth is flush with the bed surface or 0.1 - 0.3 cm lower than the bed surface. The electric heating wire is externally connected to the temperature controller and the power supply. A small arched shed is erected on the seedbed, covered with straw mat and thin film at night for heat preservation. Electric heating wires are laid on the bed surface, which can directly heat the soil around the seeds. Because the film and dry wheat bran are laid under the nutrient soil, the heat can be prevented from being transmitted downward and electricity can be saved. After electrification, soil temperature is high, seed germination is fast, seedling is early, root system is developed, seedling is short and strong. Seed disinfection and germination seeds to be prepared for sowing to remove impurities to inferior, sun seed 1~2 days, sun with "Tianda 2116"(200 times solution, special type for seed soaking) mixed with 95% meilin (3000 times solution) for soaking for 30 minutes, then soaking for 30 minutes in warm water at 55℃, finally soaking for 4~5 hours in clean water at 30℃, taking out and draining, putting into a constant temperature oven at 25~30℃ for germination, putting into a freezing box after 24 hours, freezing at-20 ℃ for 4~6 hours, then putting into well water for warming for 20 minutes, draining water to continue germination, After 12 hours, freeze again, most of the seeds can be sown white. Seedbed with warm water infiltration irrigation until the soil surface color, in the middle of each nutrient soil block flat 1 seed, radicle downward or lateral direction, after sowing soil cover 1.5~2 cm. Seedbed management After sowing, electrify and heat, cover the straw with plastic film, and control the temperature at about 25℃ to facilitate early emergence. After the seedlings emerge, the electricity is not electrified as long as the bed temperature is not lower than 15℃. In the daytime, remove the straw cover and remove the small arch shed film, so that the melon seedlings can see more sunlight, and cover the double-layer drip-free film and straw cover at night to keep warm. The bed temperature shall be controlled at 25~32℃ during the day, 18~20℃ at night, and the minimum temperature shall not be lower than 15℃. When the seedlings have more than 2 true leaves, the straw cover without drip film can be removed at night, the temperature is maintained at 15~18℃, and the temperature difference is increased to facilitate the differentiation of female flowers. For seedlings cultivated by twin-vine or multi-vine pruning, they can be transplanted with lateral vines at the 4~5 leaf stage by topping. Single vine pruned melon seedlings, 3 leaves, 1 heart stage when planting. In order to cultivate strong seedlings, opaque mulch should be removed as early as possible during seedling period, and the light time should be prolonged. When the seedlings are in the 2-leaf stage, spray Tianda 2116 (1000 times solution, special type for strong seedlings) mixed with 95% meilin (3000 times solution) for 1~2 times to prevent and control seedling diseases and promote seedling growth. If continuous cropping, in order to prevent blight and other soil-borne diseases, black-seeded pumpkin can be used as rootstock to cultivate grafted seedlings.