The Latest Winter Melon Cultivation Techniques and Methods Tutorial

Winter melon is an annual trailing or trellised herb; the stem is covered with yellow-brown stiff hairs and long soft hairs, and has ridged grooves. The fruit is pillow-shaped, hence it is also called pillow melon. It is produced in summer, because when the fruit ripens, there is a layer of white powdery substance on its surface, just like the white frost formed in winter, so it is called winter melon; for this same reason, winter melon is also called white melon. When selecting, pinch it with a fingernail: winter melon with a relatively hard skin, dense flesh, and seeds that have matured and turned yellow-brown has a good taste.

Cultivation Methods for Winter Melon

Winter melon cultivation methods can be divided into three types: ground winter melon, shed winter melon, and trellis winter melon.

1. Ground winter melon

The plants creep and grow on the ground, with relatively sparse spacing between plants and rows, generally planting about 300 plants per mu. Management is relatively extensive; the stems and vines are basically left to grow freely, or the side vines are removed before fruiting and allowed to grow at will after fruiting. Its advantages are that it requires less labor and has lower costs. The disadvantages are that the fruit shape is poor and the fruit must be frequently propped up; otherwise, the rate of deformed fruit is high. The rind is easily damaged by the external environment, affecting storability. Light energy utilization is low, the fruit size is uneven, and the yield per unit area is relatively low. This method is only suitable for gray-skinned winter melon varieties sold within the island, but not for varieties with higher commercial requirements for transport to the north or export, such as “Qingpi Dong”, “Heipi Dong”, and “Qingza No. 1”.

2. Shed winter melon

After the plants begin to vine, bamboo and wood are used to build a shed to guide the vines. There are tall sheds and short sheds. Tall sheds are generally 150-200 cm high, short sheds are generally 60-80 cm high, and the shed width is 250-300 cm. Hainan melon farmers mostly use the short shed method. Before the plants go up onto the shed, side vines are removed; after going up onto the shed, the stems and vines grow at will. Shed winter melon sets fruit better than ground winter melon, the fruit size is relatively uniform, and the yield per unit area is generally higher than that of ground winter melon. However, it still basically uses flat area, which is unfavorable for close planting. Generally, intercropping can only be done before the vines go up onto the shed, so space cannot be fully utilized; moreover, more shed-building materials are needed, and costs are high. In recent years, to save materials, costs, and labor, an improved net shed frame has begun to be promoted: first use wooden stakes and wire to build a basic shed frame, then cover it with woven fluorocarbon silk net. Nylon net can be used for at least three crops, and building the frame is very convenient and labor-saving.

3. Trellis winter melon

There are many forms of supports. There is the “single dragon”: that is, one stake per plant, fixed continuously with horizontal bamboo at a height of 130-150 cm; there is the “A-frame”; there are “one-star drum frame longan” and “four-star drum frame longan”: that is, three or four bamboo poles are used to build a drum frame, and each drum frame is fixed continuously with horizontal bamboo, one drum frame per plant. Although the forms of trellis winter melon vary widely, they all combine plant adjustment, make better use of space, increase the fruit-setting rate, and make fruit size uniform, which helps increase yield and quality; it is also conducive to intercropping and increasing the number of multiple cropping cycles; and it saves trellis materials and reduces costs compared with shed winter melon. Under current conditions, trellis winter melon is a relatively reasonable and relatively scientific method among the three cultivation methods.

Cultivation Season, Sowing and Seedling Raising, and Planting Density

1. Cultivation season

⟦NL>Winter melon likes warmth and tolerates heat. To obtain a high yield, suitable climatic conditions for winter melon fruit setting and fruit development should be selected for planting. Climatic conditions have the greatest impact on the fruit-setting rate of winter melon, so special attention should be paid to seasonal arrangement. Conditions such as clear weather, relatively high temperature, and relatively high humidity are favorable for fruit setting; dry air, low temperature, and rainy days mean fewer insects are active, which is unfavorable for pollination; and it reduces the pollen-receiving capacity of the stigma, resulting in poor fruit setting. According to the characteristics of winter melon's requirements for light and temperature conditions, in southern Hainan, cities and counties such as Lingshui, Sanya, and Ledong have winter and spring temperatures mostly above 20°C and sufficient sunlight, so sowing can be done throughout winter and spring, and normal flowering and fruiting can occur; while in northern cities and counties such as Wenchang, Chengmai, Qiongshan, Ding'an, and Lin'gao, in winter and spring, especially from early January to late February, low-temperature rainy weather below 15°C often occurs. Therefore, special attention must be paid when sowing to avoid, as far as possible, having the planted winter melon flower and set fruit during this period. When sowing winter melon, in addition to considering climatic factors, market factors should also be considered. Because the winter melon cultivated in Hainan, especially winter melon cultivated in winter and spring, has most of its products sold to markets outside the island and to Hong Kong, China and Macao, China. Therefore, in terms of cultivation season, attention should also be paid to avoiding the peak production season of winter melon in inland provinces, especially Guangdong and Guangxi. Only in this way can the cultivated winter melon achieve the goals of high yield and high efficiency. Under normal circumstances, as long as Hainan-cultivated winter melon is harvested and marketed from late December to early May, its selling price is relatively high; otherwise, it is relatively low. Accordingly, the suitable sowing period for winter melon cultivation in winter and spring in southern Hainan is from mid-September to early January; in other areas, sowing from mid-September to early October and from early December to early January is best. If sown from mid-October to late November, because the flowering and fruiting period is mostly affected by low-temperature and rainy weather in January-February, fruit setting is very difficult; even if fruit can be set, the fruit grows slowly and develops poorly, and the rate of deformed fruit is relatively high.

2. Sowing and seedling raising

For winter and spring cultivation of winter melon in Hainan, because it is often affected by low temperatures, nutrient-pot seedling raising should be adopted. The required nutrient soil should be prepared in advance; fertile garden soil that has been baked, sun-dried, and screened can be selected and mixed with decomposed pig and cattle manure residue, rice husk ash, or coconut coir, etc. The volume ratio of the three is about 6:2:2, and a small amount of nitrogen-phosphorus-potassium compound fertilizer can also be added. Its added amount is generally controlled at 0.2%-0.3%, and it must be finely crushed and mixed evenly to prevent damage to seeds and roots. For winter melon seed germination, generally first soak in warm water at 50-55°C for 10-15 minutes (stir while soaking), then continue soaking at room temperature for 10-12 hours, and finally place at about 30°C for germination. With a longer soaking time, germination is faster and more uniform, and most seeds germinate in one and a half to two days; with a shorter soaking time, germination vigor is poorer. Seeds with smooth seed coats and no edges (such as green-skinned winter melon seeds) have poor permeability, and during germination are prone to oxygen deficiency and seed rot, with a low germination rate. Therefore, for germination of such seeds, the seed coat must first be rubbed and washed with fine sand to remove attached matter, and then placed under constant temperature conditions of 28-30°C for germination. Before germination, rinse the seeds once each morning and evening with clean water, drain off the water in time, and continue germination. If there is no constant-temperature equipment, it is safer to sow directly into seedling bags or seedbeds after soaking. According to the author's experiment, soaking seeds with 100-150 ppm gibberellin can make germination rapid and uniform. The day before sowing, water the nutrient soil in the pots thoroughly. The sowing depth is 2-3 cm; sow 1-2 germinated seeds per nutrient pot. The seeds should be placed flat or with the sprout tip facing upward. After sowing, immediately cover with shade netting or straw, etc.; if a cold wave or rainy weather occurs, plastic film should be used for covering. After sowing and before emergence, pay attention to watering, but do not overwater, to prevent seed rot and root rot; just keep the soil moist. When about 70% have emerged, remove the covering in time. Before the seedlings break the heart, appropriately control moisture to promote root growth; after breaking the heart, often keep the nutrient soil in a semi-dry, semi-moist state to make the melon seedlings grow steadily. After about 25-30 days, they can be transplanted into the field. Two to three days before planting, the seedlings can be watered with 10% dilute human manure water and 800-fold 80% zineb or 600-fold 75% chlorothalonil solution, so as to transplant with fertilizer and pesticide.

3. Planting density

The planting density of winter melon varies with variety, cultivation method, and cultivation season. The yield per unit area of small winter melon is composed of three aspects: the number of plants per mu, the number of fruits per plant, and the single fruit weight. Proper close planting can increase yield. Most large winter melon varieties bear one fruit per plant, and their yield per unit area is composed of two factors: the number of plants per mu and the single fruit weight. Therefore, on the basis of ensuring single fruit weight, proper close planting should be done. Ground winter melon plants have vines and leaves growing on the ground, which is inconvenient for plant adjustment, so close planting is not suitable; shed winter melon also basically grows on a flat plane, so it is also not conducive to close planting; trellis winter melon can use space for growth, and combined with plant adjustment and vine guiding, it is conducive to close planting. At present, most winter melon varieties cultivated in Hainan production are large varieties. With flat shed cultivation, the bed width is generally about 350 cm (including ditches), double-row planting, plant spacing 70-80 cm, and about 500 plants per mu; with trellis winter melon cultivation, the row and plant spacing is generally 150×(70-80) cm, and about 600 plants can be planted per mu; ground winter melon generally has a bed width of about 400-500 cm (including ditches), double-row planting, plant spacing about 80-100 cm, and about 300 plants per mu. The planting density of winter melon is also related to the level of fertilizer and water management. If fertilizer is sufficient, drainage and irrigation are convenient, and the management level is high, then emphasis should be placed on growing large fruits to strive for high yield and high quality, and it should not be too dense. On the basis of removing all side vines, topping the main vine can allow denser planting than not topping.

Land Selection and Preparation, Applying Sufficient Base Fertilizer

The root system of winter melon is very developed, and the growth period is long. In order to obtain a relatively high yield, sandy loam to clay loam with deep soil layers, rich organic matter, and a pH value of 6-6.5 must be selected for planting; at the same time, in order to avoid cold waves at the seedling stage and early spring drought in the early stage and summer rain in the later stage for winter-spring cultivation of winter melon, it is advisable to choose fields facing south with the back to the north and convenient drainage and irrigation; autumn-winter melon is often affected by typhoon rain, so land selection should preferably be sloped dry land with convenient irrigation and drainage.

After the melon field is selected, deep plowing and harrowing should be carried out as early as possible, with a depth of about 30 cm being better. For winter-spring cultivation of winter melon, late rice fields with convenient drainage and irrigation are better. After the late rice is harvested, the field should be plowed early and sun-bleached white, and before planting, it should be plowed and harrowed again until fine. After land preparation, the planting layout should be planned and the bed surface made; then ridges should be made on the bed surface, with a ridge width of 80-100 cm and a ridge height of about 30 cm. Half-beds are left on both sides of the ridge, and shallow ditches are left between the ridge and the half-beds, to be used for ridging and topdressing during the vine-drawing period. Planting holes are set along the ridge according to plant spacing, with a hole depth of about 30 cm and a hole width of about 40 cm. Winter melon has a relatively long growth period, and its root system has strong absorption capacity; therefore, sufficient base fertilizer should be applied. The base fertilizer is generally mainly high-quality farmyard manure, more than 2,000 kg per mu, 30-50 kg bean cake, and 40-50 kg superphosphate. After composting, mix well and apply in furrows or holes, and after fully mixing with the soil, sow or transplant. For loamy soil or clayey soil, when conditions permit, 30-40 kg ternary compound fertilizer and 15-20 kg urea per mu can also be applied throughout the entire layer to meet balanced nutrient supply. For soil with a relatively heavy sandy texture, the amount should be reduced to prevent fertilizer damage.

Plastic Film Mulching

To ensure high and stable yield, plastic film mulching cultivation of winter melon can create superior cultivation environmental conditions such as temperature, light, water, fertilizer, and soil, promote the growth and development of the winter melon root system and plants, and reduce damage from certain diseases and pests as well as cold, drought, and heavy rain. Therefore, it can achieve obvious yield-increasing effects. Experiments have proven that plastic film mulching cultivation of winter melon in winter and spring in Hainan generally increases yield by 30%-50% compared with open-field cultivation; under severe weather conditions, the yield increase can sometimes even reach more than 1 times.

For plastic film mulching cultivation of winter melon, the method is generally just to cover the melon ridges. The film width selected is 80-120 cm, and colors include white, black, silver-gray, and others. White film has a good warming effect, but weeds are likely to grow, so before mulching, a pre-emergence herbicide must first be sprayed, such as butachlor or acetochlor, etc., with a dosage of 75-100 ml per mu, diluted with about 30 kg of water and sprayed on the soil surface, and then mulched; black film has a slightly poorer warming effect, but can prevent and control weed occurrence; silver-gray film can repel aphids and reduce the occurrence and spread of viral diseases. Before mulching, be sure to level and finely prepare the soil, apply sufficient base fertilizer, and keep the soil moist. When mulching, be sure to stretch the film flat and press the film edges tightly. When planting melons after mulching, be sure to water thoroughly for root establishment, and seal the openings well with fine soil. After that, be careful not to let the humidity inside the film become too high, so as to avoid root rot. As long as the soil is moist when mulching, generally no further watering is needed within about 20 days after transplanting. If water is lacking later, the method of furrow irrigation should be adopted, and only half a furrow of water needs to be irrigated.