Detailed Explanation of Kylin Watermelon Planting Techniques and Management Methods
Kylin watermelon is a new scientifically bred variety developed through cultivation. It has very high requirements for the growing environment, soil, and sunlight. However, since it takes only about 60 days from planting to flowering and from flowering to harvest, farmers in Wenzhou and Hainan are still very willing to grow it despite the demanding cultivation practices, because of its short cycle, good taste, and quick returns.
Site Selection and Greenhouse Construction
Choose a plot with high terrain, good drainage, and deep soil to build the greenhouse. Low-lying plots with poor drainage are not suitable for greenhouse construction. The plot must not have grown cucurbit crops within 3 years. In Jiangxi, rice fields are often used to grow "Kylin watermelon."
The greenhouses used for growing watermelon generally adopt a simple bamboo strip structure. The greenhouse should preferably run north-south, with a width of 4.5-5 m, a length of 25-30 m, and a height of 1.8-1.9 m. The spacing between 2 greenhouses in the same row is 80-100 cm, and the distance between two rows of greenhouses is 2.5-3 m. The moso bamboo strips generally used for building the greenhouse are about 7 m long and about 5 cm wide.
When building the greenhouse, on the plot where the greenhouse is to be built, draw the side lines of the greenhouse according to the span. At corresponding positions on the two long side lines, use a steel rod to punch a small hole about 30 cm deep every 50-60 cm. Then insert the moso bamboo strips into the pre-punched holes. When inserting the bamboo strips, alternate the base (thick end) and the top (thin end). At the top of the greenhouse, use a horizontal tie rod to firmly bind the arch rods so that the entire greenhouse is connected as one unit, with all arch rods at the top at the same horizontal level. Then install a diagonal support rod on each side at both ends of the greenhouse, cover with greenhouse film, press the soil firmly over the film edges to keep the film taut, and leave greenhouse doors at both ends.
Digging Ditches and Making Beds
1. Digging ditches: Dig drainage ditches around the greenhouse, requiring a depth of 50 cm and a width of 30-50 cm. The drainage ditches between greenhouses should be 25 cm wide and 25-30 cm deep. During heavy rain, water in the greenhouse ditches must be able to drain smoothly along the ditches, with no water accumulation, otherwise it can easily cause watermelon root rot.
2. Soil improvement: When the watermelon plot is idle in winter, the soil should be deeply plowed and exposed to sun and frost. If the soil is too acidic, quicklime can be used to neutralize the acidity. Generally, 100-150 kg of quicklime per mu is spread on the ground, then the land is plowed.
3. Making beds: Watermelon is best cultivated with deep ditches and high beds. Generally, a 4.5-5 m wide greenhouse is made into 2 beds, each about 2.3 m wide, roughly in a turtle-back shape. Each greenhouse has only one ditch in the middle, about 40 cm wide and 20 cm deep, with no ditches on either side.
4. Applying base fertilizer: One month before planting, apply 2000 kg of decomposed organic fertilizer, 25 kg of calcium magnesium phosphate fertilizer, 15 kg of potassium sulfate compound fertilizer, and 50 kg of rapeseed cake per mu. For soil deficient in boron, supplement boron fertilizer at 1.5 kg of borax per mu. The base fertilizer should be applied in a ditch opened in the middle of the bed, then covered with soil.
5. Laying drip irrigation pipes and plastic film: Half a month before planting, level the bed surface, lay the drip irrigation, and cover with plastic film and greenhouse film to raise the temperature. The ground temperature must be above 15°C before planting.
Seedling Raising Techniques
Generally, cultivation adopts the method of large greenhouse + small arch tunnel + plastic film. Where conditions permit, electric heating wires are used for sowing and seedling raising in mid-to-late December, with transplanting in early-to-mid February. Without heating equipment, sowing and seedling raising should be done in mid-to-late February, with transplanting in late March.
1. Selection of seedbed site: Seedling raising should be carried out in a greenhouse. Choose a plot close to the cultivation field, with high and dry terrain, sheltered from wind and facing the sun, with good light conditions and convenient drainage and irrigation.
2. Preparation of nutrient soil: The nutrient soil should be loose, fertile, and water-retentive, and must be composted more than 1 month in advance. Take rice field soil that has not grown cucurbit crops for more than 3 years, add decomposed farmyard manure, compound fertilizer, calcium magnesium phosphate fertilizer, and plant ash, mix well, and cover with film for composting. Rice field soil : decomposed farmyard manure : plant ash = 5:3:2. At the same time, add 5 kg of calcium magnesium phosphate fertilizer and 2 kg of crushed compound fertilizer per 1 cubic meter of nutrient soil. During mixing, 50% carbendazim 600x solution or 1% formalin solution can be used for disinfection, turned and sprinkled evenly, then air-dried and sieved.
3. Seedbed preparation: Generally, about 400 seedlings are needed per mu of watermelon. Build the seedling shed in advance and make an electric heating hotbed. Make the seedbed 1.3 m wide, dug into a concave bed 5 cm deep, with length determined by need. For insulation, lay a layer of old film at the bottom, fill in 2 cm of rice husk, cover with a layer of disease-free fine soil, pat the soil surface level, then lay the electric heating wire for warming. Lay 1000 watts of electric heating wire per 10 sq m of seedbed, sparser in the middle of the bed and slightly denser on both sides. Connect the power supply and switch, choose plastic nutrient pots of 10 cm x 10 cm specification, fill with nutrient soil, and arrange them on the electric heating wire of the seedbed, then cover with film for insulation and warming.
4. Germination promotion and sowing: Sun the seeds for one day before sowing. For germination promotion, first soak in 55°C warm water for 15-30 minutes, stirring while soaking. Or treat with 1% formaldehyde solution for 10 minutes, rinse clean with water, then soak the seeds for 6-8 hours. Then rub and wash the mucilage off the seed surface, wrap the seeds in a wet cloth, and place at 28°C-32°C for germination promotion (body temperature or an electric blanket can be used for germination promotion). Generally, after 24-30 hours, the seeds show white and can be sown. Two days before sowing, water the nutrient soil thoroughly in one application, and energize the seedbed to preheat. Control the soil temperature above 25°C before sowing. Sowing is best done on a sunny morning, one seed per pot, with seeds placed flat. After sowing, cover with 0.5 cm of fine soil, sprinkle water appropriately, then cover with plastic film and build a small arch tunnel for insulation.
5. Seedling stage management
① Temperature: Before emergence, maintain a relatively high temperature in the small arch tunnel, preferably 28°C-30°C during the day and 18°C-25°C at night. When 30% of seedlings have emerged, promptly remove the plastic film covering the nutrient pots and the small arch tunnel film for ventilation. After emergence, keep the greenhouse temperature at about 25°C during the day and 15°C-18°C at night. If the temperature is insufficient during the seedling raising period, use the electric heating wire for supplemental heating.