How to Cultivate Thin-Skinned Melons? Explanation of 7 Major Technical Points
Thin-skinned melons have traditionally been cultivated by letting the vines crawl along the ground; the vines become tangled and interwoven, making them very difficult to manage, and yields are also low. So how do you cultivate thin-skinned melons? What are the technical points?
1. Soil Selection
Melon roots spread widely and the plant has large leaves and fruit, so it has a distinctive selectivity for soil. Different soil types, fertility levels and salinity-alkalinity levels all have different effects on melon yield and quality. Only in loose-structured soil can the roots grow well. When the soil structure is tight and aeration is poor, root growth is poor. Therefore, a sandy loam soil is more suitable for cultivating melons.
2. Applying Sufficient Base Fertilizer
The absorption of nutrients by melons is positively correlated with the formation of dry matter and the accumulation of sugars, so applying more high-quality fertilizer is a key measure for obtaining high-quality, high-yield melons. According to the pattern of nutrient uptake during melon growth and development, base fertilizer should be the main source and topdressing the supplement. Thin-skinned melons grow relatively quickly and are not strict about fertilizer requirements, mainly relying on base fertilizer. Apply 60,000 kg of high-quality farmyard manure per hectare, or 1,100 kg of soybean cake plus 1,100-1,500 kg of superphosphate per hectare, or 450 kg of ammonium phosphate. Before sowing, open furrows or dig holes, mix the fertilizer and soil evenly, and apply it as base fertilizer into the furrows or holes.
3. Topdressing
Throughout its entire growth period, the melon needs to continuously absorb nutrients and, through photosynthesis, form the photosynthetic products that make up the plant body, so its demand for the three key elements nitrogen, phosphorus and potassium is relatively high. As long as a certain amount of quick-acting fertilizer has been applied in the base fertilizer, generally no quick-acting fertilizer is needed as topdressing at the seedling stage. In order to improve the cold resistance of the seedlings, promote root development and vigorous seedling growth, mainly apply quick-acting nitrogen fertilizer, and phosphorus is even better, because nitrogen grows the seedlings and phosphorus strengthens them. When topdressing with diammonium phosphate, you can mix it into diammonium water and apply it in holes, preparing about a 5% diammonium solution, using 0.5 kg of fertilizer water per plant, then water and seal the soil; or dig a semicircular furrow 15 cm from the plant on one side, apply the fertilizer into the furrow, then cover it with soil and combine with watering. However, because the air temperature and soil temperature at this stage are relatively low, it is not suitable to water heavily; you can water one plant at a time, that is, hole watering.
From vine extension to flowering and fruit set is the period of vigorous growth for melons, and the rate of nutrient absorption gradually speeds up. In order to accelerate melon growth and branching, carry out topdressing in combination with watering. Still mainly use nitrogen fertilizer, so that more nutrients are absorbed to build the plant's own organism and form a certain leaf area, laying the foundation for producing photosynthetic materials. During this period, both air temperature and soil temperature are continuously rising, and melon growth speeds up, so the method of furrow fertilization should be adopted. That is, dig a furrow 15-20 cm deep 20 cm away from the seedlings, scatter ammonium bicarbonate into the furrow, water immediately after fertilizing, and cover with soil immediately after the water seeps down.
During the flowering and fruit-setting period, if excessive vegetative growth occurs, that is, growth is too vigorous, fruit abortion and fruit drop will occur. If growth is poor, that is, nutrition is insufficient, poor fertilization will also occur, likewise causing flower and fruit drop. In order to enhance the plant's photosynthesis, promote the development and formation of the reproductive organs and increase the fruit-setting rate, continuously spray 0.3% monopotassium phosphate during the flowering and fruit-setting period. If poor seedling growth is found, you can combine this with spraying 0.5%-0.6% urea.
From fruit enlargement to maturity, especially after fruit set, both vegetative growth and reproductive growth are very vigorous, and the absorption of the three key elements reaches its peak. Furrow application should be made on both sides of the seedlings, applying 50 kg of ammonium bicarbonate and 375-450 kg of potassium sulfate per hectare, or about 750 kg/ha of plant ash, followed by watering after fertilization.
4. Rational Watering
Before sowing, irrigate enough base water, either by hole irrigation or furrow irrigation, to prepare sufficient water for sowing, emergence and seedling growth. The amount of irrigation is related to soil type, tillage depth and irrigation method. The irrigation amount per hectare is about 900 cubic meters, and furrow irrigation and hole irrigation can save 1/3 of the water. After irrigation, preserve soil moisture in time to reduce water evaporation.
Throughout the entire growth process, the amount, frequency and timing of irrigation depend on the local climate, soil type and seedling growth conditions. Especially once the fruit enlargement stage begins, water almost every day or every other day. In addition to the crop itself needing to absorb a large amount of water, 1/2 to 1/3 of the water is lost due to soil and water leakage.
You can also decide whether to irrigate by observing the plant's “appearance”. When the melon leaves are pale green and the tip of the vine grows noticeably upward or vigorously, this is a sign of excessive water in the plant; when the leaf margins curl slightly and droop at noon but return to normal by early morning after the night, this is a sign that the plant is beginning to lack water. If the leaf margins curl and droop and the leaves no longer return to normal, it indicates that the plant is severely short of water. The best time to irrigate should be when the crop begins to lack water; otherwise it will cause poor plant growth and reduce yield. Melon irrigation should basically be mainly furrow irrigation, and flood irrigation must not be used. Furrow irrigation saves water, and the depth of water seepage is 1-2 times deeper than border irrigation, creating conditions for deep roots to absorb water. With flat border irrigation, the seepage depth is shallow, so the melon roots are distributed in the shallow layer, and at the same time it causes premature aging of the plant, affecting melon quality. Therefore, it is best to use large furrow irrigation. For melons, whether at the seedling stage or the flowering and fruit-setting stage, watering should be done in the morning or evening, not during the day, and especially not around noon. At noon, the plant body is in a high-temperature state; irrigating with cold water will cause the stomata in the plant to close rapidly, physiological functions to be hindered, assimilation to decrease, and even wilting may occur.
5. Raising Seedlings
In recent years, early-maturing varieties have been used for planting thin-skinned melons, changing from the original direct sowing to raising seedlings and transplanting. Double-film small arch shelters are used for cultivation. Find a sunny piece of idle land and make a sunny seedbed. Before sowing, first select the seeds, remove mixed seeds, and choose seeds with good maturity and uniform size, then soak the seeds in warm water at 50°C. Soak melon seeds for 3-4 hours, take them out, wipe them clean, place them in a moist place, and germinate them at 25-30°C. Seeds can be soaked in 0.1% boric acid or 0.1% manganese sulfate; treatment with trace elements can increase the seed germination rate, produce uniform emergence, and promote the development of the seedling root system. Generally, after soaking for 24 hours the seeds can all germinate; once the sprouts show white, they can be sown, and full emergence can occur 3-5 days after sowing. When raising seedlings in a sunny seedbed or small arch shelter, either nutritional pots or soil blocks can be used.
6. Management After Planting
1. Temperature management
From planting to seedling recovery, keep the daytime temperature at 30-35°C and the nighttime temperature not lower than 15°C, which helps seedling recovery; generally do not ventilate for 5-7 days. From seedling recovery until the melons reach their final size, keep the daytime temperature at 25-30°C and the nighttime temperature not lower than 12°C, which helps strengthen the vines and set fruit early. From fruit sizing to maturity, keep the daytime temperature at 25-35°C and the nighttime temperature above 12°C, which helps sugar accumulation in the melons.
2. Fertilizer and water management
Water once 7-10 days after planting to help seedling recovery; after seedling recovery and until flowering, generally do not water. After the first crop of melons is set and grows to the size of an egg, water lightly 1-2 times and topdress along with the water. Generally apply 30 kg of potassium sulfate compound fertilizer per mu. When the melons stop enlarging, water heavily once, and then stop watering until the first crop of melons matures.
3. Plant adjustment
Adopt the single-stem vine-hanging pruning method with the main vine, hanging the main vine when the plant has 5-7 leaves. In principle, one leaf, one vine, one melon, and generally leave about 8-10 melons on the whole plant. To prevent flower and fruit drop, before flowering you can spray the flowers with 0.1% forchlorfenuron hormone; while spraying the flowers, remove side vines at the same time.
4. Control of main diseases
To facilitate identification and the adoption of scientific control measures, the symptoms and control methods of the main diseases are introduced as follows:
Melon fusarium wilt, also called wilt disease, is one of the serious diseases of cucurbits.
This disease occurs in all regions. It often causes large areas of plants to die. It is caused by soil-borne infection, invading the vascular bundles from the roots and root crown and then parasitizing and causing disease. Its symptom is leaf wilting, with the most severe incidence after vine extension during the fruit enlargement period, that is, the middle and late stages. At the seedling stage it causes the cotyledons and the whole plant to wilt, and the stem base becomes brown, constricted and damping-off-like. The disease occurs most often at the flowering stage, fruit-setting stage and fruit enlargement stage. In the early stage of the disease, the plant shows leaves wilting gradually from the old leaves at the base toward the top. It is especially obvious around noon, and can still recover in the morning and evening. After a few days, all the leaves of the plant wilt and droop, no longer recover, and then the plant dies.
Control measures: It is best to carry out crop rotation with cucurbit crops for more than 5 years. Disinfect seeds before sowing. Before sowing, level the land, apply sufficient decomposed organic fertilizer as base fertilizer, and irrigate enough base water. Do not irrigate at the seedling stage. During the growth period, irrigate with a gentle flow; flooding irrigation and sequential irrigation are strictly prohibited. For chemical control, you can choose 50% carbendazim or 50% thiophanate-methyl, using 7.5-15 kg per hectare. If scattered diseased plants are found in the field, you can choose benomyl, thiophanate-methyl, carbendazim, benomyl or dexon 500-1000 times solution and pour it around the plant roots, using 200-250 ml of solution per plant, once every about 7 days, for a total of 2-3 times.
Melon phytophthora blight
It is prone to occur under high temperature and high humidity, especially after rain, when the disease strikes fiercely. In the early stage of the disease, the stem base appears dark green and water-soaked, the diseased part gradually constricts and soft-rots, the leaves on the affected part wilt, and soon the whole plant wilts and dies, with the vascular bundles of the diseased plant not changing color. When leaves are damaged, they produce large round or irregular water-soaked spots that expand quickly, with indistinct edges; when dry, they appear green-wilted, and the leaves are brittle and easily broken.
Control measures: When the disease is about to occur, choose 25% metalaxyl wettable powder 800-1000 times solution, or 50% metalaxyl mancozeb wettable powder 500 times, or 64% oxadixyl wettable powder 500 times solution. You can also use 75% chlorothalonil 600 times solution, 50% anilazine 400 times solution, ridomil 25% 600 times solution, or a mixture of 25% metalaxyl plus 40% thiram 800 times solution, pouring 0.25-0.5 kg of solution per plant, once every 7-10 days, for 3-4 consecutive treatments.
Melon gummy stem blight, also called black spot disease, mainly damages vines, leaves and fruit.
It mainly occurs on the main vine and side vines; the diseased part cracks and secretes a yellow-brown gelatinous substance, which after drying becomes red-brown or black block-like. In the later growth stage, the diseased part gradually dries up, and the spots appear gray-white. On the fruit, water-soaked spots initially appear, and the center becomes a brown dead spot, causing the melon to rot.
The control measure is to thoroughly spray at the early stage of disease with 70% mancozeb 500 times, 50% thiophanate-methyl or carbendazim 500 times solution, 70% chlorothalonil 600 times solution or 50% sulfur mixture suspension 500-600 times.
7. Harvesting
When the melon skin has good brightness, the color changes, and there is a loss of fuzz, the melon is ripe; generally it gives off fragrance, and it can be picked. The growth period is 80-100 days. Thin-skinned melons are best harvested at nine-tenths ripe. At this time the melon has good color, the sweetest taste and high commercial value. To judge ripeness, look for the fruit changing color, the surface fuzz completely shed and a fragrance present, and the stem end becoming soft; then it can be picked. When harvesting, leave a 2-3 cm fruit stalk.