How to grow watermelons in greenhouses and in what month?

How to grow watermelons in greenhouses and in what month?

Watermelon greenhouse cultivation is a precision and intensive cultivation, which is very technical and requires comprehensive supporting measures to achieve the goals of early maturity, high yield and high efficiency.

1. Preparing and fertilizing the soil. Early-maturing watermelons in greenhouses are generally cultivated at a high density, so careful soil preparation is required. If a greenhouse is used during the winter, it should be plowed 25 centimeters deep before winter and frozen bags should be made to loosen the soil. Spread half of the base fertilizer over the entire surface, then dig it into the soil, level it and then dig trenches to concentrate on fertilizing and making borders. During soil preparation, the roots of the previous crop should be picked out of the shed.

Generally, small high ridges and high borders can be used to make borders in greenhouses, with a row spacing of 1-1.2 meters. In the case of dense planting with brackets, grafting cultivation, double-vine pruning and leaving one melon per plant, it is appropriate to make small high ridges with a row spacing of 1 meter. When cultivating on the ground, a north-south border (parallel to the longitudinal direction of the greenhouse) can be used.

The amount and type of base fertilizer: Generally, 4000-5000 kilograms of high-quality manure (or 3000-4000 kilograms of decomposed chicken manure), 50 kilograms of superphosphate, 15-20 kilograms of potassium sulfate, and 100 kilograms of decomposed cake fertilizer are applied per mu. Half of the organic fertilizer in the base fertilizer is applied during general plowing, and the other half is applied in the high-yield ditch.

2. Transplanting and planting. When watermelons are covered with three layers of film in greenhouses, they can be planted about 10 days earlier than in double-covered greenhouses. The planting density in a greenhouse can generally be higher than that in a double-covered greenhouse, and requires more careful pruning of branches. Cultivation using scaffolding is denser than cultivation on the ground. It is not appropriate to plant too densely in a greenhouse, especially in areas with heavy rain and weak light in spring.

How to plant watermelons in greenhouses: First, mark the planting points according to the spacing between plants on the border of the film, then choose a sunny day for planting, and finish planting between 9 a.m. and afternoon. The size of the planting hole should be compatible with the size of the soil lump or nutrient bowl. Then pour an appropriate amount of bottom water into the hole, and plant the seedlings when the water just seeps down. When planting seedlings, first carefully take off the plastic bowl and plant the complete soil lump into the planting hole so that the surface of the soil lump is flush with the border surface or slightly exposed. After arranging the melon seedlings, fill them with soil. Gently compact the filled soil with your hands along the perimeter of the soil lump. You can also leave the nest temporarily unsealed on the day of planting, and then water a small amount of water the next day before sealing the nest to facilitate slowing down the seedlings. After the whole shed is planted, the border surface can be cleaned, and a small arch frame can be inserted on the ridge surface, and a film can be buckled on it to form a one-stop small arch shed. Since there is no wind in the greenhouse, the arch frame can be simpler, and the small arch shed can also be covered with mulch film, and it does not need to be pressed tightly so that it can be uncovered during the day and night when the weather is warm. In order to replenish the seedlings, some more backup seedlings should be planted in the shed at the same time. In order to increase the soil temperature on the day of planting, it is best to complete the planting before 2-3 pm.

3. Temperature and humidity control in the greenhouse.

① Humidity management. Within 5 to 7 days after planting, attention should be paid to raising the ground temperature and keeping it above the temperature to promote the growth of seedlings. If the temperature is higher than 35 degrees during the day, you should try to shade and cool down. After slowing down the seedlings, ventilation can be started to adjust the temperature in the shed. Generally, it should not be higher than 3T-32 degrees during the day and not lower than 15 degrees at night. During this period, the temperature of the shed can be controlled by opening and closing the skylight. When the melon vines are about 3T centimeters long, , the small shed can be removed. During the flowering period of greenhouse watermelon, sufficient light and high night temperature should be maintained, because if the night temperature is low after artificial pollination, it will cause fruit drop and affect fruit hypertrophy. When the outside temperature exceeds 18 degrees, ventilation should be increased, and the skylight and both sides of the shed should be ventilated at the same time. Keep the daytime temperature no higher than 30 degrees to prevent excessive day-night temperature difference and excessive day temperature. During this period, the watermelon enters the expansion and maturity stages. High daytime and excessive daily temperature differences will cause the fruit flesh to deteriorate and its quality to decline.

②. Humidity management. The relative humidity of the air in the greenhouse is high. Under the condition of covering with plastic film, the air humidity can be significantly reduced. Generally, the air humidity in the shed is low in the early stages of watermelon growth. However, after the plants are full of vines and leaves (for scaffold cultivators) or the rows are closed (for crawling cultivators), due to the large amount of transpiration, the amount of irrigation water also increases, causing the air humidity in the shed to drop. increase in height. The relative humidity is generally between 60% and 70% during the day and reaches 80% and 90% at night. In order to reduce the air humidity in the shed and reduce diseases, measures such as closing the shed appropriately at night during sunny and warm days, increasing air circulation, and spreading grass between rows to reduce soil surface evaporation can be adopted. In the middle and later stages of growth, it is appropriate to maintain the relative humidity at 60-70%.

4. Adjustment of light and gas components.

① Increase the amount of lighting. Watermelon requires strong light intensity. However, due to condensation on the surface of the greenhouse film or the surface being unclean, the light intensity in the greenhouse is often reduced, especially when it is covered with multiple layers. Therefore, you should pay attention to keeping the shed film clean and do not use old films with poor light transmission. The light in the greenhouse mainly comes from the top (upper light) and the side (side light). The ground film also has a certain reflective effect in the early stage of growth. In the case of close-planting cultivation on scaffolds, the normal photosynthesis of the leaf area more than 1 meter above the ground has a great impact on watermelon yield. Therefore, during the growth period of watermelon, the light from the top and both sides of the greenhouse should always be kept unobstructed to enter the greenhouse, so that the leaves above 1 meter in the greenhouse can get enough light in the middle and late stages of growth. Therefore, strict pruning, timely pruning and cutting are required. Topping, keep the top blades 30-40 cm away from the roof film to prevent the rows, top and sides from being blocked. When tying the vines, pay attention to leaving a 20-30 cm gap between the leaf layers to prevent them from overlapping.

②. Gas regulation in the shed.

Under the closed conditions of the greenhouse, the carbon dioxide content in the air is seriously insufficient, which affects the normal progress of photosynthesis and the accumulation of assimilation products. Carbon dioxide fertilization is to artificially increase the carbon dioxide concentration in the greenhouse and supplement the insufficient carbon dioxide content in the greenhouse. Methods include: first, stacking fresh horse manure in the shed, which can release carbon dioxide during the fermentation process. Stack 5 to 6 kilograms per cubic meter of space; second, burning propane gas can produce carbon dioxide. In a greenhouse with an area of ​​600 square meters, burning 1.2-1.5 kilograms can increase the carbon dioxide concentration in the greenhouse to 1.3 ml/liter. The amount of burning propane gas can be determined according to the area of ​​the greenhouse; the third is to use a coke carbon dioxide generator. Carbon dioxide can be released when coke is fully burned; fourth, the simplest way is to put concentrated hydrochloric acid in a non-corrodible container, and then put a small amount of stone flow (calcium carbonate) into it, and carbon dioxide can be produced through a chemical reaction. The period for carbon dioxide fertilization is mainly during the peak growth period of watermelon, especially the fruit development period; the suitable time is around 10 a.m. when photosynthesis is at its peak, and the optimal concentration is 1-1.5 ml/L. Ventilation methods must be adopted to keep the air in the shed fresh and prevent the accumulation of harmful gases.

5. Prune and tie vines.

①. Pruning. Under dense planting conditions in greenhouses, stricter pruning should be implemented. When the main vine is stretched out, the main vine is 30-50 cm long, and the side vines have also obviously stretched out. When the side vines grow to about 20 cm, select one strong side vine and remove the rest. Later, the side vines growing on the main and side vines will be removed as needed. Leave another 10-15 leaves above the melon joints for topping. The pruning work is mainly carried out before the melons sit down. In the case of support cultivation, the work of removing side vines (forking) should be carried out until the frame is full and topping. When removing the side vines, remove the tendrils.

②. Build a frame and tie the vines. In the case of greenhouse support cultivation, vertical stands should be used. Bamboo poles and hanging ropes can also be used, but it is better to use thick bamboo poles, because bamboo poles are not easy to fall. More than 20 days after planting, the main vine is about 30 cm long. After removing the small arch in the greenhouse, insert it immediately. You can insert two bamboo poles for each melon seedling. On both sides of the plant, more than 10 cm away from the root of the plant, the bamboo poles It should be inserted firmly and upright. After inserting the stand, start to lead and tie the vines. When the vines are 30 to 40 centimeters long, the creeping melon vines can be led onto vertical poles, one pole for each vine. Pay attention to managing the vines during the vine tying operation. In the later stage, be careful not to knock down the large melon. When tying the vines, Can be combined with pruning work. In the case of ground climbing cultivation, the vine management method of greenhouse watermelon is basically the same as that in double-cover cultivation. However, because it is in a greenhouse, the vines can be introduced and pruned in time after the vines are stretched, and measures such as pressing the vines can also be omitted. In the case of climbing cultivation in greenhouses, stricter pruning should also be adopted, and the double-vine pruning method should be used when planting densely.

6. Artificial pollination. Due to the flowering habit of watermelons in the greenhouse, pollination should be carried out at 8-9 am. On cloudy days, the male flowers will disperse their powder late, so it can be delayed appropriately. In order to prevent the male flowers from dispersing their pollen late on cloudy and rainy days, you can retrieve the male flowers that can bloom the next day in the afternoon of the first day and place them indoors under dry and warm conditions so that they bloom and disperse on time the next morning, and then use these flowers to pollinate the female flowers. Pollination should begin with the second female flower. In order to keep the melon.

7. Choose melons or melons. In order to increase the weight of a single melon and make the melon shape correct, you should choose a melon with the second female flower sitting on it. If you leave the melon too early, the melon will be small and the shape of the melon will be incorrect. If you leave the melon too late, it will not be conducive to early market. Generally, 3-5 days after pollination, When the melon fetus grows obviously, the melons should be left on the main vines first; if the melons are left on the main vines, the melons can be left on the side vines. In the case of support cultivation, when the melons grow to about 0.5 kilograms as big as the mouth of a bowl, the melons should be hung in time to prevent the young melons from falling after enlarging. In the case of ground climbing cultivation, melon selection, cushioning and turning of melons should be carried out as in greenhouse cultivation.

8. Topdressing and irrigation. Watermelons in greenhouses should not be watered too much in the early stage. Generally, after slowing down the seedlings, if the ground is not dry, there is no need to water; if it is too dry, water can be irrigated once along the ditch. After that, keep the ground wet and dry, control irrigation, and increase the ground temperature to make the melon seedlings strong. During the spreading period, water can be poured twice before inserting the stent. Just a moderate amount of water. Do not water during the flowering and fruit setting period to prevent leggy growth and promote melon setting. After the young melons grow to the size of an egg, they enter the melon expansion stage. You can water them once every 3-4 days to promote the expansion of the young melons. For top dressing of watermelons in greenhouses under scaffold cultivation, shallow ditches can be opened on both sides of the melon ridges before the scaffold and after the small arches in the greenhouse are removed, and 20 kg/acre of nitrogen-phosphorus compound fertilizer and 5-10 kg/acre of potassium sulfate can be applied. Promote root extension and plant growth, and lay the foundation for flowering and fruit setting. After the young melons sit down and grow to the size of eggs, apply 20 kilograms of compound fertilizer per mu (combined with irrigation and flushing) to promote the growth of the melons. After the fruit is set, 0.3% potassium dihydrogen phosphate can be used as foliar top dressing 1-2 times. When harvesting the second crop of melons, you can sit on the second crop of melons and topdress 15 kg/acre of ternary compound fertilizer after the first crop of melons are harvested.

9. Pest and disease prevention and other management. The main pest of watermelon in greenhouses during the growth period is aphids. To prevent and control aphids, DDV + dimethoate (1:1) 2000 times can be sprayed on the seedbed before planting. During the peak period of melon expansion, the vines and leaves in the shed are lush, the air circulation is poor, and the occurrence of aphids is severe. Care must be taken to prevent and control the crops by spraying pesticides closely. The main disease is powdery mildew, which should be prevented and treated as soon as possible. Anthracnose prevention and treatment should be started during the melon expansion period. In the middle and later stages of growth, attention should be paid to strengthening ventilation and reducing the air humidity in the shed, which can greatly reduce watermelon diseases. Watermelons are cultivated in greenhouses, especially on supports. Since the watermelon fruits are under good protection conditions and receive good light, the fruits have a correct shape, bright skin color, and no yin and yang sides, so high-grade watermelons can be produced.

How to grow watermelons in greenhouses

1. Choose improved varieties

[1] Varieties

Choose cold-resistant, disease-resistant, high sugar content, good commercial properties, and Early-maturing watermelon varieties for storage and transportation, such as specially selected Jingxin, Xinhongbao, King of Kings, Xinong No. 8, Jingxin No. 2, etc.

[2] Seed quality

Seed purity should be above 98%, germination rate should be around 90%, and clarity should be above 90%.

2. Crop arrangement

In early spring large arch shed cultivation, multi-layer covering techniques such as adding small arch sheds and covering with mulch film are used to increase the ground temperature and air temperature as much as possible. Huachi County is suitable for sowing in mid-to-late February, planting in late April, and harvesting in early to mid-June. The yield is high and the benefits are good.

3. Seedling cultivation

[1] Production methods and specifications of seedling pots

Use old newspapers, waste mulch films, shed films and other materials to make bottomless circles Tube, the specifications are 8cm×8cm or 10cm×10cm; the finished plastic nutrition bowl can also be used directly.

[2] Preparation of nutrient soil

Mix 7 parts of pastoral soil (fertile soil that has not been planted with Cucurbitaceae crops), 4 parts of fully decomposed high-quality farmyard manure, 1 part of decomposed Pound horse manure and 1 part of plant ash finely, mix well and sift, add 40g of 50% carbendazim to every cubic meter of nutrient soil (make it into an aqueous solution and mix it with the nutrient soil), and use 40% isosaphos-methyl 1,000-1,500 times liquid to kill insects (eggs). Cover the pile of nutrient soil with plastic film and stuff it for 2-3 days before loading it into a pot for later use. When filling the pot, leave a 3cm-high space in the pot to facilitate covering with soil after sowing.

[3] Seed treatment

Choose a sunny day to dry the seeds for 1 day, and use 50-100g of seeds for 667 square meters. Soak the seeds in warm water of 55 ℃, and stir continuously when pouring the warm water. , wait until the water temperature drops to 30°C, soak the seeds for 1 hour, and then soak the seeds with 40% formaldehyde 200 times for 30 minutes. After washing the seeds, soak them with 30°C warm water for another 8-10 hours, take them out, wrap them in a wet towel, and put them away. Germinate under 30℃ conditions, wash with warm water once a day, and sow after 80% of the seeds are white.

〔4〕Selection of seedling fields

Use sunny borders to raise seedlings. The seedling fields should be chosen with an east-west leeward direction and facing the sun, which is convenient for transplanting and transportation. A 60cm high earth wall was built on the north side of the border, and gables were built on the east and west sides in an arc shape. The top was covered with film and covered with thatch at night. The width of the seedling border is 1.5-2 m and the depth is 25-30 cm. The length is determined according to the number of seedlings.

[5] Sowing

Choose sunny and good weather for sowing around February 15th. Place the nutrient pots neatly in the seedling bed, water them thoroughly, and after the water has seeped down, spray 3 kg of water per square meter with 2 mL of Transplanting Spirit on the bed surface, and then sow the seeds after the water has penetrated into the soil. Sow 2 seeds to promote germination in each nutrient pot, cover them with 2-3 cm thick nutrient soil, then cover the entire seedbed with film, and cover with thatch at night.

[6] Seedbed management

Before emergence, the thatch should be uncovered during the day and covered at night. The shed film should not be opened. The temperature should be controlled at 30-35 ℃ during the day and 20 ℃ at night. After the seedlings have emerged, cover them with 1cm of nutritious soil to support the seedlings. Before the first true leaf unfolds, the temperature is slightly lowered to 25-28 ℃ during the day and 15-18 ℃ at night. Watering depends on the condition of the seedbed, usually every 2-3 days. Allow the air to cool down the seedlings 7 days before planting to improve the survival rate.

4. Planting

[1] Land preparation and fertilization

Watermelon fields must be plowed deeply in autumn and plowed 1-2 times after thawing the following year. During autumn plowing, apply 5000kg of high-quality farmyard manure, 15kg of diammonium phosphate, 25kg of superphosphate, and 10kg of potassium sulfate to 667m2. Apply them all at once during land preparation, and then plow deeply; at the end of March of the following year, plow and rake the land, and then apply phosphoric acid. 30kg of diammonium, 10kg of potassium sulfate, 50kg of decomposed bean cake, and 30kg of high-efficiency compound fertilizer.

[2] Ridging and covering with film

Ridging 10 days before planting, ridge width 1.2m , the width of the ditch is 0.3m, the middle of the border is slightly higher and is arcuate, and then covered with a film with a width of 1.4 m. The direction of the border is east-west.

[3] Build a shed

Warm the ground 5 days before planting. The steel frame greenhouses in Huachi County are built according to the specifications of 40m×6m, and the shed membrane is fixed with ropes or lamination lines to prevent the membrane from being damaged by strong winds.

〔4〕Planting

Choose a good day for planting around April 15th. Plant 1 row per ridge, row spacing 1.5 m, plant spacing 45-50cm, 850-980 plants planted in 667 m2 . When planting, use a seedling transplanter to drill holes, and fill each hole with 1 kg of water. Plant the seedlings after the water has seeped down. After planting, seal the holes tightly with soil, and then tighten the shed film. After the seedlings are planted, water them along the ditch.

5. Post-planting management

[1] Temperature management

After transplanting, close the shed on time, let the air out, and adjust the temperature inside the shed. Before slowing down the seedlings, keep the temperature at 30°C during the day and above 15°C at night; after slowing down the seedlings, keep the temperature at 25-28°C during the day and 12°C at night.

〔2〕Water and fertilizer management

〔3〕Promoting water for the plant

After slowing down the seedlings, the watermelon grows rapidly and enters the mass stage (5-leaf stage). In order to promote the growth of the plant and make it spread quickly, it is necessary to irrigate and topdress as soon as possible, and topdress 10kg of urea and 10kg of diammonium phosphate to 667m2. Then water the furrow and till dry to maintain moisture and promote root development.

[4] Expanded melon water

After the fruit is firmly set, fill the melon with expanded melon water once more when it is about the size of an egg, and topdress 15 kg of potassium sulfate and 15 kg of potassium sulfate to 667 square meters 20 kg of high-efficiency compound fertilizer. During the watermelon expansion period, you can re-irrigate with a small amount of water once depending on the situation. The water amount is generally 1/3 of the ditch depth. Flooding with large water should be avoided to avoid flooding the border surface and causing rotten seedlings and dead seedlings. In the late stage of melon formation, use 0.3% potassium dihydrogen phosphate or 0.2%-0.3% urea solution to foliarly spray the watermelon leaves until the leaves turn yellow and eventually wither. Topdress the roots. You can also spray watermelon, amino acids, organic ecological fertilizers, etc. Spray once every 10 days. How to grow watermelons in greenhouses in early spring 8424

(flush application) 5 kg of seaweed water-soluble fertilizer for leaf melons/acre

(spray application) 40 g/mu of special foliar fertilizer for leaf melons Mu

Melon nutrition plan

1. After transplanting - during the vine extension period

Flush application: Water the root once after transplanting and during the vine extension period Spray once to promote root retardation and seedling growth, and reduce dead seedlings;

Spraying: Spray twice continuously, 7-10 days apart, to promote and strengthen flowers, and increase the melon setting rate;

2. The melon sitting period - the melon swelling period

Flush and apply: When the melon is about the size of an egg, flush it once. The melon shape is correct, the melon expands quickly, the flesh is bright red, and the taste is crisp and sweet; during the expansion period, Spray 1-2 times for fast expansion and sweet taste;

Leaf spray: Continuously spray 2 times from the beginning of the melon setting period to promote strong flowers, increase the melon setting rate, and reduce cracked melons and navel rot. ;

3. Post-harvest recovery - end of two melons

Fertilization: 2 consecutive applications with an interval of 5 days. In the future, each batch of melons will be irrigated twice to prevent vines from falling. Restore vine vigor, reduce yellow leaves lacking nutrients, expand melons quickly, and increase yield in the later period;

Leaf spray: reduce yellow leaves lacking nutrients;

Utilize greenhouses The cultivation of high-end gift watermelons in protected areas such as Shanghai, Zhejiang, Shandong, Beijing and other places has now reached a large scale. In recent years, the introduction, research and promotion have also begun in southern provinces, especially the Yangtze River Basin, which has produced good economic and social benefits. For example, the "Early Spring Ruby" watermelon, which is commonly seen on the market, is sold in most large and medium-sized cities across the country and is favored by consumers. Using greenhouses to cultivate gift melons in early spring is a good way to generate income and increase efficiency.

Greenhouse construction Watermelons are cultivated in greenhouses in the south. The primary function of the greenhouse is to prevent rain, followed by heat preservation. Watermelons are most afraid of too much rain. In the south, there is a lot of rain, especially in spring and summer, which results in unstable watermelon production in the region. Rain-proof cultivation under greenhouse cover can better solve this problem. Plastic greenhouses should be built on land with high terrain, easy drainage, sufficient sunshine, and suitable for growing watermelons. Paddy fields and fields that have not been planted with melons for many years are better. Generally, the width is 7 to 8 meters, the length is 25 to 30 meters, and the height is 2 to 2.5 meters. Bamboo frame sheds, cement sheds or steel frame sheds can be used. This form of cultivation requires a large investment, and site selection is the key. Generally, it is only suitable for planting in the same location for one year. In the second year, it should be changed to a suitable planting plot that has not been planted with melon crops for many years. Therefore, when building a greenhouse, it should be considered to be detachable. efficacy.

Variety selection It is advisable to choose high-end varieties for greenhouse cultivation of watermelons in early spring to achieve the goals of high-end, high quality and high efficiency. At present, the most widely used variety in production is early spring ruby. Other varieties include Zaojia, Xiaolan, Xinjinlan, Xiuli, Xiuya, Bingjing, Huameiren, Hongxiaoyu, Huangxiaoyu, etc.

Seedling raising Early seedling raising is the basis of this technology. Generally, seedlings should be raised in January to February around the Spring Festival when there are 7 to 10 consecutive sunny days. Nutrient bowls are used to concentrate the seedlings in the greenhouse, with multi-layer coverage. There should be thermal insulation and anti-freeze facilities, such as geothermal heating wires and high-power light bulbs, to facilitate germination and sowing, so that seedlings can emerge as soon as possible and reduce the chance of frost damage. From January to March, the temperature in the Yangtze River Basin is low and there are frequent cold snaps. When raising watermelon seedlings, frost damage is most likely to occur from sowing to the seedling stage, especially from sowing to the emergence stage. There is a danger in 1 to 2 days below 10 degrees, so try to avoid cold waves. Or use heating protection facilities. In addition, keeping the seedbed and nutrient soil as dry as possible is also an effective measure to improve cold and disease resistance. In order to promote the growth of seedlings, watering with fertilizers and water must be carried out on sunny days. The nutrient soil will dry out 1 to 2 days after watering, which will help improve the plant's resistance to cold and disease.

Covering: Three layers of covering are generally used for early spring cultivation, namely greenhouse, small shed and mulching film. The advantages of full coverage with plastic film are: enhanced heat and water retention performance, no weeds growing, watermelon vine leaves and fruits not stained with soil, fertilizer and water can be irrigated under the film, reducing the infection of diseases and insect pests, and improving the appearance of the fruit.

Fertilization Since the mulch is fully covered, top dressing is relatively difficult, so sufficient base fertilizer must be applied before planting. The base fertilizer is suitable for slow-acting fertilizers such as cake fertilizer, livestock manure, soil fertilizer, potassium sulfate compound fertilizer, etc., but it must be fermented, and quick-acting fertilizers should be used sparingly. For watering and top dressing, drip irrigation under the film is used, that is, a drip irrigation pipe is placed 50 cm away from the planting in front of the film cover. The fertilizer is fermented, soaked, and filtered before drip irrigation, which is beneficial to protecting the watermelon vine leaves and fruits.

After each batch of melons is picked, top-dress fertilizer in time to facilitate continuous fruit setting.

Plant and fruit management: When the plant grows to about 1 meter, perform 3-4 vine pruning to ensure that each plant sets 2-3 fruits at a time. Generally, pruning is done in the afternoon on a sunny day to avoid breaking and damaging the vine leaves. , and is beneficial to wound healing and reducing disease infections. In early spring, due to low temperatures and few insects, it is difficult to set melons. Measures such as artificial pollination and bee release can be used to promote fruit setting. In order to improve economic efficiency, melons can also be sold at low festivals and listed early. Deformed melons and cracked fruits should be removed promptly. Small watermelons are generally of good quality. They are of high quality when they are eight ripe. Especially in high-temperature seasons, they mature more than 20 days after fruit setting. They should be picked and put on the market in time, otherwise they are prone to overripeness. If long-distance transportation is required, carton packaging should be used to avoid cracking. How to grow red jade watermelons in greenhouses in early spring

Early spring ruby ​​​​right? Ruby is a gift type watermelon, ranking first among watermelons with its unique taste and sweetness! My planting usually involves three-arm pruning, two main arms and one negative arm! Erdao Guanniu Zuomei Watermelon cultivation in greenhouses can withstand several degrees of low temperature

The temperature and humidity in the greenhouse should not be lower than 15 degrees at night. ① Humidity management. Within 5 to 7 days after planting, attention should be paid to raising the ground temperature and keeping it above the temperature to promote the growth of seedlings. If the temperature is higher than 35 degrees during the day, you should try to shade and cool down. After slowing down the seedlings, ventilation can be started to adjust the temperature in the shed. Generally, it should not be higher than 3T-32 degrees during the day and not lower than 15 degrees at night. During this period, the temperature of the shed can be controlled by opening and closing the skylight. When the melon vines are about 3T centimeters long, , the small shed can be removed. Greenhouse watermelon planting technology

Land preparation and planting. Watermelon likes sandy loam with strong permeability, and low-lying water storage land and rice fields cannot be chosen. Apply 5,000 kilograms of farmyard manure per acre at one time, and add 15 kilograms of diammonium and 5 kilograms of potassium fertilizer. Drill the ridges normally, plant two ridges and leave one empty ridge, and leave a ditch between the two ridges. The seedlings can be transplanted in late April, and 1,700 seedlings per acre are maintained. The pits are dug according to a spacing of 0.4 meters, and a small amount of diammonium is applied to each pit. After watering, plant the seedlings and cover them with mulch. Prick the mulch on the seedlings to allow the seedlings to protrude from the holes, seal the roots of the seedlings with fine soil, fasten them with a small arch, and then use a large arch and then fasten the small arch.

Management: Open the air when the temperature exceeds 25℃ during the day, and close the air when the temperature drops to 20℃. When the outside temperature remains above 15°C during the day, dismantle the small shed and leave only the mulch film and the large shed. The large shed should be kept from beginning to end. The large shed should be closed at night and on rainy days to avoid direct contact with rain and dew, which can cause melon vine bunch disease in the event of drought. Irrigate the furrows under the mulch. The humidity in the shed is within 50-60%, and if it exceeds 70% for a long time, it will easily cause disease. Pick when the seedlings have 4 to 6 true leaves. After 3 to 4 vines have formed melons, remove all the vines behind the melons and leave 3 to 4 leaves on the vines in front of the melons.

Pest and disease control The main diseases of melons include downy mildew, powdery mildew, and fusarium wilt. The pest is aphids. Rotate the sprays of Aphrodisiac and Trichosanthes every 7 days. If aphids are found, they can be controlled with dimethoate. Stop using pesticides 15 days before harvest.

1. Site selection and land preparation. Watermelons are drought-tolerant and afraid of waterlogging, so they cannot be cropped continuously. The site should be well-ventilated and fertile sandy loam soil. Generally, gardens for continuous watermelon planting are not selected. The land preparation must be deeply plowed and carefully cultivated, and the border ditch, waist ditch, and surrounding ditch are connected to facilitate the cultivation. irrigation and drainage.

2. Fertilizer and water management. Applying sufficient base fertilizer and reasonable top dressing is the prerequisite for high yield and high quality of watermelon. Base fertilizer accounts for about 60%-70% of the total amount. The application method is to apply it in trenches between rows or in holes. The main application is organic fertilizer. 100kg of cake fertilizer per mu. 50kg of bone meal. Farmers without cake fertilizer and bone meal can use 50-80kg of ternary compound fertilizer, 2000kg of stable manure, and 2000-3000kg of high-quality compost. Top dressing depends on the watermelon breeding period. After the watermelon is successfully established, sufficient seedling fertilizer should be applied, that is, 20kg of ternary compound fertilizer per mu should be applied in the ditch or hole, and 10-10 kg of ternary compound fertilizer should be applied when there are 5-6 true leaves. 20kg. When the young fruit is firmly established (the size of an egg), the melon fertilizer will be used to expand the melon and strengthen the fruit. That is, apply 1000kg of decomposed human excrement or 50kg of ternary compound fertilizer per acre in ditches or holes. The watermelon growth period can be combined with disease and insect control. Top dressing outside the roots (0.3% potassium dihydrogen phosphate + 0.3% urea solution) preserves leaves and increases yield. Greenhouse watermelon planting technology ppt

), requiring artificial pollination.

Pay attention to diseases. Watermelons can be planted in greenhouses in August

. Greenhouses are said in the south, and greenhouses with only skeletons and film are said in the north. They have earth walls, skeletons, films, and heating devices. Jilin belongs to the northeastern region. Winter is cold and suitable for greenhouses. I hope this can help you.