First, widen the temperature difference between day and night. The temperature in the greenhouse is controlled at about 35℃ during the day and 18℃ at night, and the temperature difference above 1℃ is beneficial to the accumulation of sugar in photosynthetic products and increase the sugar content of melon. Second, increase the application of phosphorus and potassium fertilizer and control nitrogen fertilizer. High nitrogen content in the soil, insufficient potassium fertilizer, vigorous plant nutrition growth, hindered the transfer of photosynthetic products to fruits, thus reducing the quality of melon. Therefore, phosphate fertilizer and potassium fertilizer should be increased and the amount of nitrogen fertilizer should be controlled in order to improve the sugar content and quality of melon. 2 kg of potassium sulfate compound fertilizer can be applied with water per mu, and 5 times of potassium dihydrogen phosphate solution can be sprayed on the leaves to supplement phosphorus and potassium fertilizer. Third, reduce the amount of watering in the middle and late stages of fruit expansion. Reducing the amount of watering in this period can not only improve the sweetness of melon, but also reduce the proportion of cracked melon. Because the water supply situation in the middle and late development stage is also directly related to the sugar accumulation and transformation in melon fruit, the plant absorbs more water, but the sugar accumulation is less, and the melon is tasteless, so it is better to minimize the watering amount and not water it for 8 ~ 1 days before maturity. Fourth, maintain good ventilation and light transmission conditions. Good ventilation and light transmission conditions must be maintained in the shed to promote the full expansion and development of fruits and the accumulation of sugar. It is necessary to remove the old leaves, yellow leaves and diseased leaves at the bottom of the plant in time, and release air in time during the day to ensure that the plant absorbs enough carbon dioxide to meet the requirements of photosynthesis. ---------Proper cultivation methods will also increase sweetness. 1. Selecting land, preparing soil and applying fertilizer.

Melons are drought-resistant and waterlogged-resistant, and prefer sandy soil to clay. It is best to choose sandy loam with high terrain and good drainage, and the previous crop should be corn, wheat, etc., and avoid soybean and melon < P > crops. If possible, it is best to turn over the land in autumn, with a depth of 2 cm, and rake it flat and thin, which is conducive to moisture conservation. In spring, it is necessary to top the pulp and make ridges and apply farmyard manure.

The root system is developed, and it has a strong ability to absorb nutrients from the soil. Under normal growth, the absorption ratio of nitrogen, phosphorus and potassium is 2:1.3:7, but the demand for nitrogen, phosphorus and potassium is different throughout the growth period. The demand for fertilizer in seedling stage is not large, but it needs more nitrogen and phosphorus in vine-stretching stage, and the demand for potassium gradually increases after melon planting, and the fruit swells to a peak at home.

Adding phosphorus and potassium fertilizer in combination with nitrogen fertilizer can increase the yield of melon, increase the sugar content and reduce the incidence rate. Therefore, it is necessary to apply fertilizer scientifically. First, base fertilizer should be applied well, depending on the soil fertility and the quality of farm manure. Generally, 4,-5, kilograms of fermented chicken manure, 15 kilograms of diammonium phosphate and 25 kilograms of potassium sulfate should be applied per mu, because melon

.

2. Seed selection and seedling raising

Seedling raising time is 3 days before planting in open field or greenhouse, usually in early April, around Tomb-Sweeping Day. First, pick some variegated and deformed seeds as clean as possible from the sense. Sun-dry the seeds two days before soaking. After being exposed to sunlight, they will break the dormancy state and sprout neatly, which is beneficial to Miao Qi and Miao Zhuang. Soak the sun-dried seeds in hot water of about 55℃ for 6-8 minutes before accelerating germination. Pay attention to the fact that the water temperature should not be too high, and soak the seeds for 4-6 minutes after the water temperature is naturally cooled. After soaking the seeds, take out the clean mucus, and then pour it into the medicine which is 3-4 times the amount of seeds < P > to soak the seeds. The commonly used medicines are the following seeds. .1% potassium permanganate for 2-4 hours, 6-7 times of 2% fukuning,

for 2-4 hours, 5 times of 7% thiophanate methyl or 1 times of 5% carbendazim for 3-4 minutes, and you can choose one. Seed

should be stirred frequently when soaking in the medicine to make the seeds absorb medicine evenly. Accelerating germination: wash the seeds soaked in liquid medicine with clear water once, put them in a pot, cover them with a towel and put them on the kang for accelerating germination. The temperature is required to be between 28-32℃ < P >, and they can sprout completely in 16-24 hours. Sowing: The common method of seeding seedlings in nutrient pots is that the nutrient soil filled with nutrient pots consists of field soil, decomposed farm manure, appropriate amount of phosphorus < P > potassium fertilizer and chemicals, and the suitable field soil is corn stubble soil (5%), peat soil (3%) and decomposed pig manure and chicken manure (2%). About 25kg of fine soil is added with .5kg of potassium dihydrogen phosphate < P > and .5kg of seedling mother agent, and then it is put into a bowl. After the nutrition bowl is installed, the seedlings are moved and leveled, placed tightly, and watered once. After water infiltration, a layer of < P > is covered with pesticide soil, with a thickness of .2cm, and then two germinated seeds are placed, and then covered with pesticide soil with a thickness of 1cm. After all, it is covered with plastic film.

3, seedling management

The management of this period is very important. In order to be healthy when planting, good melon seedlings should pay attention to heating and insulation, and the temperature should be kept at 3-35℃ during the day,

at night, it is best to be above 18℃ and not below 15℃, and the temperature difference between day and night should be shortened as much as possible, so that seedlings can emerge after three days; After the seedlings are fully grown, the temperature in the shed should be properly controlled, and it should be kept above 25℃

during the day and above 18℃ at night. If the temperature is too low or too high, it will lead to the occurrence of seedling damping-off. When the seedlings grow to three leaves, it is necessary to prevent them from growing in vain. The seedlings should be tempered 7-8 days before planting, and the shed should be uncovered during the day and covered at night on sunny days. Watering should be strictly controlled throughout the seedling period, and the seedlings should not be watered.

4. Planting

When planting, first make holes in the ridge covered with film with a hole punch according to the plant spacing of about 4 cm, and then put the seedlings in the planting holes with nutrition pots. After planting, the seedlings should be watered

, and then the holes should be sealed after water infiltration. The brackets are generally covered with arch film, and the spacing is about 1 meter, which should not be too wide.

5. Field management

During this period, it is sunny and the temperature is high during the day, so it is necessary to ventilate well. Vents of the arch shed should be opened after 8 am and sealed before 4 pm. Vents should be opened every 1 meters on the leeward side of the arch shed. With the increase of temperature, the temperature in the greenhouse should be controlled within 3-35℃ to ensure the normal growth of melon seedlings.

The sugar content of the produced melon will definitely increase if cultivated by the above methods.