Key Techniques for Cultivating Muskmelon in Low Tunnels

Variety selection: Choose varieties with a growing period of within 100 days, early flowering, easy fruit setting, early maturity and strong disease resistance, such as Elizabeth and Zhongtian No. 1.

Raising strong seedlings: Seedlings are generally raised in greenhouses or hotbeds, with the seedling raising time in mid-to-late February. Before sowing, seeds should be disinfected, soaked and pre-germinated. For disinfection, pour water at 55 degrees Celsius into the container holding the seeds for warm water soaking, stirring while pouring. When the water temperature drops to 30 degrees Celsius, soak the seeds for 6 to 8 hours before pre-germination. The pre-germination temperature is generally 28 to 30 degrees Celsius.

Sowing: It should be done at noon on a sunny day. Before the seedlings emerge, the temperature should be 25 to 30 degrees Celsius. After 70 to 80 percent of the seedlings have emerged, control the daytime temperature at 20 to 25 degrees Celsius and the nighttime temperature at 15 degrees Celsius to prevent excessive growth. After the first true leaf unfolds, raise the temperature inside the tunnel, keeping it at 25 to 30 degrees Celsius during the day to promote root development and strong seedlings. One week before transplanting, carry out low-temperature hardening, controlling the daytime temperature at 15 to 18 degrees Celsius and the nighttime temperature at 12 degrees Celsius.

Transplanting: Before transplanting, prepare the soil and apply fertilizer.

① Transplanting time: The transplanting time is an important factor determining early maturity and high yield. If transplanted too early, the soil temperature is too low and survival is poor. If transplanted too late, the goal of early maturity cannot be achieved. The best transplanting time should be when the local average daily temperature is above 10 degrees Celsius. Choose sunny and windless weather for transplanting, and cover with film immediately after transplanting to preserve heat.

② Transplanting method: Generally, single-row cultivation on high beds is used. Plant seedlings at a spacing of 35 to 40 cm in the center of the bed, slightly to the south. The advantage of single-row cultivation is that the seedlings remain in the tunnel for a longer time. Plant 900 to 1000 seedlings per mu.

Temperature management after transplanting: The key point in the early stage after transplanting is cold prevention and heat preservation. Keep the low tunnel tightly closed for 5 to 7 days after transplanting to increase temperature and preserve moisture and promote seedling recovery. After seedling recovery, control the daytime temperature at 28 to 30 degrees Celsius, with the nighttime temperature not lower than 10 degrees Celsius. When the tunnel temperature rises to 28 degrees Celsius in the morning, ventilate. First uncover the film at both ends of the tunnel for ventilation, and cover it well again after the temperature drops. In the afternoon, when the tunnel temperature drops to 25 degrees Celsius, close the ventilation opening to ensure the nighttime temperature does not become too low. As the outside temperature rises, gradually increase the ventilation amount. During the flowering and fruit-setting period, control the daytime temperature at 27 to 30 degrees Celsius and the nighttime temperature at 15 to 18 degrees Celsius.

Pest and disease control: The main pests and diseases include leaf blight, gummy stem blight, downy mildew and aphids. For leaf blight and gummy stem blight, procymidone, iprodione and mancozeb can be used for control. For downy mildew, metalaxyl plus mancozeb can be used for control. Control should begin at the early stage of plant disease onset, once every 7 to 10 days, for 3 consecutive times. For aphids, imidacloprid is generally used for control.