Detailed Explanation of Key Melon Cultivation Techniques and Management Methods
Melon (Cucumis melo L.), also known as oriental melon, Hami melon, etc., is an annual vining herbaceous plant of the Cucurbitaceae family. Stems and branches are angular. Tendrils are slender, single, and covered with fine pubescence. Petioles are long with grooves and short bristles; leaf blades are thickly papery, rough on the upper surface, covered with white stiff hairs. Flowers are unisexual, monoecious.
Melon Planting Time
Under normal conditions, melons are suitable for open-field planting in March to April, and greenhouse planting around February.
Melon is a spring-sown crop. Blindly sowing too early can cause seed rot, and even if seedlings emerge, they will be threatened by frost; sowing too late means a late market date, a short plant growth period, and a certain impact on yield and quality.
The suitable sowing period for melons should be determined according to the local frost-free date, cultivation method, and weather conditions of that year. For general open-field direct sowing, the suitable sowing period is 4 days before the local frost-free date; after sowing, full emergence occurs in 7 to 10 days, and by then frost has ended outdoors. For seedling-raising cultivation, the suitable sowing period is generally 1 month before the frost-free date.
If using small arched-tunnel plastic film covering cultivation, the sowing period can be advanced by another 10 to 15 days. However, the frost-free date in each area may come earlier or later in different years, and in Shandong, after the frost-free date of April 20, a cold air mass often occurs and harms melon seedlings, sometimes even forcing replanting. Therefore, before sowing, pay attention to recent weather forecasts and observe surrounding phenological phenomena, such as leaf growth, the degree of fruit tree flowering, and soil temperature, to determine the sowing period more timely and reliably.
Melon Cultivation and Management: 1 Sowing and Seedling Raising
Thin-skinned melons are mostly grown in the open field, but in recent years some have also been cultivated for early spring maturity in small arched tunnels, achieving good economic returns. Thick-skinned melons are mostly cultivated in greenhouses in spring and autumn, mainly for early-maturing cultivation.
Melon is a warm-loving crop, and seedling growth requires relatively high temperatures. Therefore, the sowing time for spring protected cultivation depends on the conditions of the protection facilities. In solar greenhouses and plastic greenhouses, seedlings are generally raised from late December to late January; in medium and small arched tunnels, seedlings are mostly raised in early February, with a seedling age of generally 35 to 40 days.
Before sowing, first soak and sprout the seeds: soak the seeds in warm water at 55 to 60 degrees C while stirring, then when the temperature drops to about 30 degrees C, continue soaking for 4 hours, then disinfect with potassium permanganate solution for 20 minutes, then rinse with clean water 2 to 3 times, remove and air-dry the surface moisture, then wrap well in a wet cloth and place under conditions of about 25 to 30 degrees C to sprout. You can also soak the seeds in a 500-fold carbendazim solution or 10% trisodium phosphate for 15 minutes, then wash clean and sprout, and sow after sprouting.
Winter seedling raising should be carried out on seedling beds in the greenhouse, with film added at night for insulation. Spring seedling raising can be carried out in sunny beds or arched tunnels, with straw mats added at night for insulation.
Delayed cultivation of thick-skinned melons uses solar greenhouse arched plastic tunnels for delayed cultivation and can be raised in the open field from early July to late July.
Before sowing, fill the seedling bed, seedling tray, or nutrient pot with fully decomposed nutrient soil made from organic fertilizer and phosphorus-potassium fertilizer, or with special seedling-raising substrate. Then water thoroughly, and sow when the early spring temperature is stable above 15 degrees C. After sowing, cover with soil 1 to 1.5 cm. For early spring seedling raising, after sowing and before emergence, keep warm at 28 to 32 degrees C during the day, not lower than 17 degrees C at night; after emergence, the temperature can be appropriately lowered, maintained at 22 to 25 degrees C during the day and 15 degrees C at night. In the later stage of seedling raising, the temperature should be lowered and watering stopped to harden the seedlings, promote root growth, and if there is a cold snap, pay attention to insulation and frost protection. Summer seedling raising occurs in the hot and rainy season; after sowing, an arched frame should be set up on the bed and film added when it rains to prevent rain damage and prevent seedling spindling.
Melon Cultivation and Management: 2 Field Planting
The suitable seedling age for melon is 30 to 35 days. When seedlings grow to the 3-leaf-one-heart stage, it is the suitable planting period. Melon has a strong root absorption capacity. Loosened sandy soil with thick soil layers and fertile soil quality is best; melon is relatively salt-alkali tolerant and can also grow on lightly alkaline soil.
Melon absorbs relatively comprehensive nutrients during growth and development. Its nitrogen, phosphorus, and potassium ratio is 2:1:3.7, and potassium chloride-type fertilizers should be prohibited. Before planting, apply 4000 to 5000 kg of decomposed organic fertilizer per mu or 100 kg of potassium sulfate controlled-release fertilizer as base fertilizer. After fertilizing, deeply plow the land 30 cm, harrow fine and level, then form ridges or beds; greenhouse cultivation mostly uses high ridges. Generally, ridges are made at a distance of 60 to 70 cm for small rows and 80 to 90 cm for large rows. Arched tunnel cultivation can use semi-high ridges or flat beds. First spread 2/3 of the fertilizer and plow the land, then make beds with a small bed width of 60 cm and a large bed width of 170 cm. Apply the remaining 1/3 of the fertilizer into the small beds, mix soil and fertilizer evenly, then rake the bed surface level.
When planting, open furrows on the ridge surface or in the small beds to plant seedlings, water, cover with soil, and cover with plastic film. Large-fruited varieties are planted at 1500 to 1800 plants per mu, and small varieties at about 2000 plants. Thin-skinned melons mostly crawl and grow on flat ground, generally planted at about 900 to 1000 plants per mu.
Melon Cultivation and Management: 3 Management After Planting
1. Watering and Topdressing
For melons cultivated in greenhouses in early spring, the temperature is low at planting time and water evaporation is low; after watering at planting, attention should be paid to insulation and watering should be controlled. After seedling recovery, cultivate and hoe in stages, and spray Tianda 2116 Strong Seedling Spirit at 600-fold dilution to promote robust seedling growth. At the vine extension stage, apply a three-element fertilizer with relatively high nitrogen content once in combination with watering; during the fruit enlargement stage, 10 kg of potassium sulfate, 10 to 20 kg of monopotassium phosphate per mu, or fluid fertilizer can also be applied. During the growth period, foliar fertilization with 0.2% monopotassium phosphate or photosynthetic micro-fertilizer can also be applied 2 to 3 times. Melon is a chlorine-sensitive crop and should not be given large amounts of compound fertilizers containing chlorine, especially those containing dichloride.
2. Pruning, Pinching, and Vine Hanging
Melon has very strong branching ability, and most varieties mainly bear fruit on secondary vines and tertiary vines. Therefore, generally when the melon seedlings grow to 4 to 5 true leaves, pinching is carried out to promote side branch growth. After young melons set, pinch the secondary vines again to promote nutrient transport to the young melons and promote their enlargement.
The pruning method for melons can be chosen according to the fruiting habits of different varieties. Generally, thick-skinned melons cultivated in greenhouses mostly use single-vine or double-vine pruning. Single-vine pruning is when the main vine is pinched at 4 to 5 true leaves, leaving one robust secondary vine at the base, and removing all other secondary vines. After the tertiary vines growing from nodes 7 to 11 of the retained secondary vine bear fruit, pinch 1 to 2 leaves ahead of the fruit. When the secondary vine grows to 25 to 30 leaves, pinch it too, and remove all tertiary vines that do not bear fruit. Thin-skinned melons are generally pinched when the seedlings grow to 5 true leaves, leaving 4 side vines; after tertiary vines grow, retain flowers and fruit on the tertiary vines. Pinch 3 to 4 leaves ahead of the fruit on the tertiary vine. Generally, retain 4 to 6 fruits per plant; after fruit setting, let them grow without further pruning.
Melons cultivated in greenhouses are generally grown with branch vines or hanging vines. Double-vine pruning means pinching the main vine at 3 to 4 leaves and selecting two robust secondary vines, then selecting flowers and retaining fruit at nodes 11 to 12 in the middle of the secondary vines.
When stems and vines grow to 50-60 cm, begin staking and tying the vines, or use nylon rope or hemp rope to guide them, letting the melon vines climb upward.
3. Artificial Pollination and Fruit Hanging
Melon is a monoecious crop with unisexual flowers, and most varieties have bisexual flowers, mainly pollinated by insects. When the temperature is low in early spring and there are few insects, artificial pollination is generally required for greenhouse cultivation. After female flowers open, before the day's temperature rises to 20 degrees C, remove newly opened male flowers of the day, peel off the petals, and gently smear the stamens onto the stigma of the female flower. After pollination, hang a tag indicating the date to determine the harvest time. Generally about one week after pollination, when the young melon grows to the size of an egg, select and retain melons. Remove excess flowers and young melons. When the young melon grows to the size of a fist, hang the fruit, using plastic rope or nylon rope with one end tied to the fruit stalk, or use a straw ring under the young melon, or hang it with a plastic mesh bag, tied to the wire on a support or indoor horizontal frame.
Melon Cultivation and Management: 4 Harvesting
The maturity of the melon should be determined according to the characteristics of different varieties and the pollination date. The harvest time can also be judged according to changes in melon skin color and weather changes. Never pick unripe melons for market. Picking melons is suitable in the morning or evening; it is best to use scissors to cut off the fruit stalk together with a section of vine, which is beneficial for storage and transportation.
For some varieties whose fruit stalks easily fall off when the melon is ripe and whose flesh easily softens after ripening, they can be picked appropriately earlier.
Melon Cultivation and Management: 5 Pest and Disease Control
1. Diseases
The main diseases of melon include fungal diseases such as anthracnose, powdery mildew, fusarium wilt, leaf blight, phytophthora blight, leaf spot, downy mildew, and phytophthora blight, as well as viral diseases. For fungal diseases, in addition to comprehensive management measures and cultivating robust seedlings to reduce disease occurrence, in the early stage of disease, powdery mildew can be controlled with triadimefon at 1500-fold dilution; 40% Fuxing emulsifiable concentrate at 8000 to 10000-fold dilution; 10% Shigao water-dispersible granules or 25% Xiansheng wettable powder at 400 to 600-fold dilution by alternating spraying.
For fusarium wilt and leaf blight, Tianda Hymexazol at 1500-fold dilution and Tianda Yufeng at 600-fold dilution, or 70% mancozeb at 500-fold dilution and 64% Sandofan wettable powder at 800-fold dilution can be used for spray control.
For downy mildew, 52.5% Yikuaijing water-dispersible granules at 1000-fold dilution, 50% Anke wettable powder at 2000-fold dilution, 72.2% Previcur at 800-fold dilution, 64% Sandofan wettable powder at 800-fold dilution, as well as Tianda Yufeng, Xiansheng, Yibao, etc. can be used for control.
For bacterial diseases, 72% agricultural streptomycin or Xinzhimycin at 400-fold dilution, 50% promethazine at 1500-fold dilution, 60% Baitai water-dispersible granules at 1000-fold dilution, etc. can be selected, sprayed once every 7 to 8 days for 3 to 5 consecutive times, for effective control.
2. Insect Pests
The main insect pests of melon include aphids, whiteflies, yellow squash beetles, leafminers, and root maggots. For aphids and whiteflies, 3% Tianda acetamiprid emulsifiable concentrate at 1500-fold dilution, 25% rotenone emulsifiable concentrate at 800-fold dilution, 25% Decis emulsifiable concentrate at 1500-fold dilution, 10% imidacloprid wettable powder at 2000-fold dilution, and 25% Actara water-dispersible granules at 3000-fold dilution can be used for spray control, and yellow sticky boards can also be used for trapping and killing. For American serpentine leafminer and yellow squash beetle, 2% Tianda abamectin emulsifiable concentrate at 2000-fold dilution, 1.8% Anfuding emulsifiable concentrate, 48% Lorsban emulsifiable concentrate, or 48% Tianda chlorpyrifos at 1500-fold dilution can be used for control.
For underground pests such as root maggots, 50% phoxim, 48% Lorsban, 48% Tianda chlorpyrifos, 48% Diquling, and Tianda Mieyoubao can be used for seed dressing or root drenching control.