What is the reason for the yellowing of egg flower leaves? pay attention to topdressing / controlling the amount of water.

Egg flower is a kind of flower with high ornamental value, which can be seen in many gardens in our country. However, if this beautiful flower appears yellowing, it will also affect its overall aesthetic feeling. What is the reason for the yellowing of egg flower leaves? Next, the editor will take you to learn about it.

What is the reason for the yellowing of egg flower leaves?

1. Improper fertilization

Fertilizer is one of the main nutrients in the process of egg flower growth, only sufficient fertilizer can make egg flower grow better, if the fertilizer is too little, its nutrients will be insufficient, which will also cause egg flower leaves to turn yellow.

Note: although fertilizer is one of the main nutrients of egg flower, it must be diluted with water before fertilization, so that egg flower can be absorbed. If it is not diluted, it will burn the plant.

two。 Too little watering

In the process of breeding, if too little watering is also one of the reasons leading to the yellowing of egg flower leaves, although the requirement of egg flower for water is not too high, it is not good to water too little. Generally, it needs to be watered once in 3-4 days during the growing period.

Note: when watering egg blossoms, we should keep the principle of dry watering, not too little, but not too frequently, generally wait for the basin soil to dry, water thoroughly when watering, do not cause stagnant water, otherwise it is easy to cause rotten roots.

3. Long-term exposure

Although egg flower is a kind of light-loving plant, it can not be exposed for a long time in strong light, which will also lead to egg flower leaves yellowing. Other seasons are fine. Summer is also the season with the highest temperature of the year. In this season, we must control the light, do not leave it outside for a long time.

Note: spring and autumn festival photos are relatively mild, we can put egg flowers outside breeding, but in summer, it is best to move to indoor semi-shade breeding, so as to avoid the phenomenon of yellowing caused by direct light.

4. Diseases and insect pests

In the process of cultivating egg flower, if it is not properly maintained, there will be diseases and insect pests, such as shell insects, whitefly, aphids, diseases and insect pests will cause egg flower leaves yellowing, so we must pay special attention to the maintenance process.

Note: in the process of egg flower culture, if there are diseases and insect pests, it must be dealt with in time, if the time is prolonged, it will not only cause the leaves to turn yellow, but also lead to the phenomenon of plant withering and death. specific prevention and control methods can refer to the article on pest control of egg flower, which is introduced in detail.

Planting conditions and cultivation management techniques of watermelon

Watermelon is the main summer fruit in summer, the flesh is crisp and tender, sweet and juicy, rich in mineral salts and a variety of vitamins, is the largest fruit sold in summer and autumn in China. In order to improve the yield and quality, the cultivation techniques of watermelon are introduced as follows:

Biological characteristics

1. Morphological characteristics.

① root: the root of watermelon belongs to deep root, the main root is more than 1 meter deep, and the lateral root extends 4-6 meters laterally. The main root group is distributed in 10-40 cm soil layer and has strong ability to absorb fertilizer and water. The ability of root regeneration is weak, and it is not easy to recover after injury. Direct seeding is often used in production. If seedlings are transplanted, we must pay attention to the protection of roots.

② stem, leaf: watermelon stem, also known as vine, the main vine grows upright in front of 5-6 leaves, and when it grows more than 30 cm to a certain length, it grows on the ground because the mechanical tissue is underdeveloped and cannot support its own weight. The branching ability of the stem is very strong, and it can germinate 3-4 grade lateral branches, but the lateral branches from 3-5 leaf axils of the main vine are more strong. Adventitious roots are easily produced on the stem nodes of watermelons. The method of pressing vines can promote the formation of adventitious roots, increase the absorption area, fix plants and prevent seedling rolling. The leaves are alternate, and there are deep, lobed, entire and other types.

③ flowers, fruits, seeds: watermelon flowers small yellow, monoecious, solitary in leaf axils. The early-maturing varieties gave birth to the first female flower at the sixth and seventh nodes of the main vine, while the middle and late-maturing varieties produced the first female flower after the tenth section. The number of internodes of female flowers is 7-9 nodes. A small number of bisexual flowers can appear in the peak flowering period, and the flowers open in the morning and close in the afternoon. The fruit is oval, spherical, dark green, light green, or with black-green stripes or markings. The flesh of melon is red, yellow, white and so on. The seeds are black, white, or red. Watermelon can also be divided into big-seed watermelon, small-seed watermelon and seedless watermelon according to the size of its seeds. the 1000-seed type is 100g ~ 150g, the medium seed type is 40g ~ 60g, and the small seed type is 20g ~ 25g.

2. Birth cycle

The whole growth period can be divided into four stages: germination stage, seedling stage, vine stage and fruit stage.

① germination stage: from seed germination to cotyledon expansion, true leaf exposure is the germination stage. After the seedlings are unearthed, it is necessary to prevent overgrowth in order to promote the development of roots and leaves.

② seedling stage: from true leaves to 5-6 leaves are seedling stage. The growth in this period is small, and good conditions should be given in cultivation to promote the differentiation of seedling roots and organs.

③ trailing stage: from the beginning of 5-6 leaves to the opening of female flowers with melon nodes. In this period, the growth rate is fast and the growth rate is large. In cultivation, it is necessary to promote the growth of stems and leaves and form certain nutrients. at the same time, it is necessary to control overgrowth and ensure the formation of flower organs.

④ fruiting stage: from the flowering node of the female flower to the exuberant growth of the fruit. It can be divided into three periods: fruit setting period, fruit growth peak period and fruit changing period.

⑤ fruit setting period: from the opening of female flowers to the beginning of exuberant fruit growth. Photosynthate begins to be fed into the fruit. In cultivation, it mainly regulates the balance between vegetative growth and fruit development to ensure melon setting.

The vigorous growth period of ⑥ fruit: from the rapid growth of the fruit to the time when the size of the fruit is basically fixed. In this period, the fruit has a large growth and absorbs the most nutrients, which is the key period for the formation of yield. Large fertilizer and water should be given in cultivation to promote the rapid growth of fruit.

⑦ ripening period: the fruit size is basically fixed to the mature stage. In this period, the sugar content is transformed rapidly, and the appearance has the inherent color of the variety. In cultivation, premature senescence of stems and leaves should be prevented in order to ensure yield and quality.

3. Requirements for environmental conditions

① temperature: watermelon likes warm, dry climate, not cold-resistant, the optimum temperature for growth and development of watermelon is 24-30 degrees, the optimum temperature for root growth and development is 30-32 degrees, and the lowest temperature for root hair generation is 14 degrees. Watermelon needs a large day-night temperature difference in the process of growth and development, and a large day-night temperature difference can cultivate high-quality watermelon.

② moisture: watermelon is drought-tolerant, not moisture-tolerant, overcast and rainy days, excessive humidity, susceptible to disease, low yield and poor quality.

③ light: watermelon likes light. Under the condition of sufficient sunshine, the yield is high and the quality is good.

④ nutrients: watermelon has a long growth period and high yield, so it needs a lot of nutrients. Every 100kg watermelon needs to absorb 0.19kg of nitrogen, 0.092 kg of phosphorus and 0.136 kg of potassium. However, there are obvious differences in the amount of nutrients absorbed by different growth stages, accounting for 0.01% in the germination stage, 0.54% in the seedling stage and 14.6% in the vine stage. The fruiting period is the most vigorous period for watermelon to absorb nutrients, accounting for 84.8% of the total nutrient content. Therefore, with the growth of the plant, the fertilizer requirement of watermelon gradually increased, and reached the maximum value when the fruit grew vigorously.

⑤ soil: watermelon has strong adaptability, and the sandy soil with loose soil, deep soil layer and good drainage is the best. Like weak acid, PH5-7.

Suitable sowing time

The open field cultivation of watermelon is the cultivation without protective equipment. Generally speaking, the local final frost has passed, and the suitable time for sowing in the open field is when the ground temperature is stable at about 15 ℃. The best time for sowing should also be determined according to the variety, cultivation season, cultivation mode and consumption season. Generally sowing and raising seedlings in mid-and late-March, planting in mid-and late-April, harvesting and listing in late June; sowing in the first and middle of July and harvesting in late September.

Apply sufficient base fertilizer for soil preparation

The cultivation of watermelon should choose the land with loose soil, deep soil layer, fertile soil, good drainage, sufficient light and western sun; watermelon field is not suitable for continuous cropping and should be rotated every 4-5 years. Otherwise, the Fusarium wilt is serious; the previous crops such as rice and corn are the best, followed by potatoes, cabbages and other vegetable crops, but the watermelon disease is serious and should not be selected.

Melon fields must be ploughed deeply, preferably in winter. In the land that has been deeply ploughed or has a deep ploughing foundation, drainage ditches are opened around, ditches are opened according to the cultivated row spacing of 2.4-3.0 meters (0.5 meters wide), and basic fertilizers are applied on one side of the border. 2500-3000 kg of farm manure is applied per mu, 15 kg of phosphate fertilizer, 20 kg of 45% compound fertilizer, 2 kg of borax and 1 kg of zinc fertilizer are applied. In order to control underground pests, a small amount of crystal trichlorfon can be mixed with base fertilizer. Cover the basal fertilizer ditch, form a melon ridge and finally cover the plastic film, waiting for sowing or transplanting. When opening the box, it should be noted that the box line is perpendicular to the spring and summer wind direction, and the wind first blows into one side of the box surface to apply basic fertilizer, so that the melon vine is consistent with the wind direction after planting.

Soaking seeds to accelerate germination

1, seed soaking: soak the seeds in the sun for 1 day before soaking the seeds, soak the seeds in warm water that is not hot (about 30 ℃) for 6-8 hours, and then remove the mucous membrane on the seed coat by wrapping the seeds with a towel or coarse cloth. In order to prevent Fusarium wilt, soak the seeds with 1000-fold solution of methyl topiramate for another 4 hours, the general soaking time is 12 hours, and the seed coat can be taken out and rinsed with clean water to prepare for germination.

2. Sprouting: put the soaked seeds flat on a wet towel, cover the seeds with a layer of wet towels, put them in an environment of 30-35 degrees and germinate in 72 hours. 85-90% of the seeds can be sown.

Sowing or transplanting

1. Direct seeding: open a shallow trench or hole with a depth of 8 cm ~ 10 cm near the application of basic fertilizer on the melon ridge, plant spacing 45-50 cm, sow 1-2 seeds in each hole, (after watering once in drought) cover soil 2 cm ~ 3 cm, those who accelerate germination and direct sowing can emerge after 2-3 days; generally use 150 grams ~ 200 grams per mu.

2, seedling transplanting: seedling age 30-35 days, melon seedlings 3 leaves and 1 heart began to transplant, plant spacing 45-50 cm, about 450-500 trees per mu, fixed root water after transplanting.

Field management

1. Intermediate ploughing and drainage: mid-ploughing begins after sowing or planting and returning seedlings, which is generally carried out by the combination of interseedling, loosening soil and soil cultivation. Watering at the seedling stage should be less, and attention should be paid to "squatting seedlings" to facilitate root growth. When the vine is 30 cm long, it is necessary to apply heavy fertilizer and then cultivate the soil. Watermelon has large fruit, high yield and large water demand. Irrigation should be paid attention to in dry land cultivation, while drainage is particularly important in paddy field cultivation. It is emphasized that the drainage ditches around the border and field should be connected with each other, and there is no stagnant water in the field after rain, which is the basis to ensure the high and stable yield of watermelons. Stop irrigation 6-8 days before fruit ripening to promote sugar transformation and increase sweetness.

2. Topdressing: the basic principle of topdressing in melon field is: light application of seedling fertilizer, first promotion and then control, skillful application of vine fertilizer, and re-application of expanded melon fertilizer after sitting on the young fruit.

① fertilizer for promoting seedlings: fertilizer for promoting seedlings is generally applied within a week after transplanting or at the 4-5 leaf stage of direct seeding seedlings, and a small amount of available fertilizer is applied when the base fertilizer is insufficient or the fertilizer effect of the base fertilizer has not been brought into full play. Generally, each plant is applied 8 grams of urea (or 20 grams of ammonium sulfate) and covered with soil after ditching and fertilization.

② trailing fertilizer: can be carried out before and after vine extension, generally when melon seedlings grow to 40-60 cm, urea 10-12 kg per mu, calcium superphosphate 8 kg, potassium sulfate 13 kg per mu, or 45% potassium sulfate ternary compound fertilizer 18-22 kg per mu, 25 cm 30 cm away from the melon root or between the two plants, the ditch depth is 10 cm 15 cm. After application, cover soil and water to promote the absorption of fertilizer.

③ expanded melon fertilizer: the expansion period is the period when the watermelon needs the largest amount of fertilizer in its lifetime. When the watermelon eggs are big, the root system is covered with the whole bed. Many melon farmers will apply expanded melon fertilizer in the hole at this time. Because the hole fertilizer is too concentrated, it will burn out the roots around the fertilizer application site, and at the same time, it is not conducive to the rapid decomposition and transformation of fertilizer, which is quite different from the characteristics of large fertilizer, large water, quick and comprehensive fertilizer in the watermelon expansion period. Therefore, it is best to use human and animal manure water and dissolved chemical fertilizer to expand melon fertilizer. When the watermelon egg is large, the circle about 30-45 cm from the root base of the melon (the extension side of the key melon vine) is poured with dung water plus compound fertilizer and urea, and the melon farmers without manure are mixed with water after dissolving with compound fertilizer 8 kg, urea 4.5 kg and potassium sulfate 5 kg. The concentration of expanded melon fertilizer should be light, and water should be used to adjust fertilizer, so that the fertilizer can play a role quickly in a short time, especially when the soil is drier. Foliar fertilizer spraying was carried out in the later stage, and 0.4% potassium dihydrogen phosphate solution was sprayed every 7-10 days for a total of 2-3 times.

3. Pruning: the leaves of watermelons are luxuriant. If the watermelons are allowed to overlap each other, it will not only affect close planting, but also delay melon bearing. Watermelon pruning methods generally have single vine, double vine and three vines and so on. Single vine pruning leaves only one vine per plant. The method of removing all the other lateral vines is simple, with more plants per unit area and more melons, but less leaves per plant, fruit is not easy to grow, yield and quality are low. Double or three-vine pruning generally leaves the main vine, when the main vine grows to more than 30 cm, double-vine pruning is to leave a strong side vine at the base, three-vine pruning leaves two strong side vines as auxiliary vines or reserve vines, and the rest of the side vines are removed; double-vine pruning is often used in production. When pruning watermelons, one should pay attention to timely pruning. Generally, when the length of the main vine is 40-50 cm, the lateral vine is about 15 cm, and then every 3-5 days; second, no matter which pruning method is adopted, it is required to be carried out seriously before fruit setting, and generally no longer pruning after fruit setting, so that there are more branches and leaves to provide nutrition for fruit growth. When the fruit begins to expand rapidly, the heart can be removed in order to prevent the vegetative growth from becoming too prosperous.

4. Press the vine: when the vine is 30 cm long, the vine should be adjusted to make its distribution uniform, and a lump of soil should be used to press the vine on the node to promote the production of adventitious roots, fix the leaf vine, prevent each other from shading each other and being damaged by the wind, and then press every 5 to 6 knots until the vine leaves grow all over the border. There are two ways to press the vine: open pressure and dark pressure. In rainy areas, the soil moisture is high, in order to prevent rotten vines, it is not necessary to bury all the melons and vines in the soil, only the soil blocks are pressed on the nodes, and the internodes are still exposed to the ground, which is called "open pressure". In order to promote the occurrence of adventitious roots in dry areas with less rain, all melons and vines should be buried in the soil as "secret pressure". In order to prevent breaking the crisp tender melon vines, pruning and pressing should be carried out in the afternoon. No matter which pressure method is used, it should be determined according to the growth of the plant. Strong growth should take heavy pressure, diligent pressure, weak growth of light pressure, less pressure. Generally, it is pressed once every 5-6 knots, and two places are pressed before and after each melon. Leave 2-3 leaves before and after leaving the female flowers without pressure, in order to prevent stagnant water rotten melons, or melons grow up to be restrained.

5. Artificial pollination: watermelon is a cross-pollinated crop that relies on insects as a vector. In rainy weather or less insect activity, it will affect the spread of pollen and it is not easy to set fruit. In order to improve the fruit setting rate and realize the ideal fruit setting position, artificial pollination should be carried out.

① female flower selection: the well-developed female flowers on the main vine and lateral vines should be selected during pollination. The flowers with thick bud stalk, enlarged ovary, normal appearance, bright green and glossy color are easy to set fruit and grow into high-quality melons after pollination. The female flowers on the side vines are used as reserve melons.

② pollination time: the flowers of watermelon began to loosen at 5 ~ 6 o'clock in the morning, and the physiological activity was the most exuberant at 8 ~ 10:00, which was the best time for pollination. In cloudy days, the time of pollination was postponed to 9 ~ 11:00 because of late flowering.

③ pollination method: using the fresh male flowers that opened and pollinated on the same day, squeeze the petals toward the pedicel with your hands, and then point the stamens of the male flowers at the stigma of the female flowers and dip them gently. One male flower can give 2 to 3 female flowers.

6. Melons: generally leave the second and third female flowers to bear melons. Early-maturing varieties can reserve the first to third female flowers, after sitting, according to the "two, one, three" order to retain a melon. The second to fourth female flowers can be reserved for middle and late maturing varieties, and one melon will be selected after sitting down in the order of "three, two, four". If the melons on the main vine are not seated, the melons should be kept in the same order on the side vine. It is appropriate to leave 1 melon per plant.

7. Watermelon fruit care: in the stage of flowering, fruit setting and fruit development of watermelon, careful care of fruit is also the key link to improve the yield and quality of watermelon. Nursing measures include protecting melon, cushion melon, turning melon, vertical melon, sun melon and cover melon and so on. From the female flower to before and after fruit setting, the epidermis of ovary and young melon are very delicate and vulnerable to wind, insect bite and mechanical damage. at this time, paper bags and plastic bags are used to cover the young melons. When the fruit grows to 1-1.5 kg, break the soil under the melon and cover it with grass or fine sand, that is, the melon. Turning the melon means constantly changing the landing position of the fruit, so that the surface of the melon is evenly exposed to light, the skin color is the same, and the maturity of the flesh is uniform. Turning melon is generally carried out in the middle and later stage of expanding melon, turning once every 5-6 days, can turn 2-3 times, turn melon should be reduced in sunny afternoon stalk moisture, not easy to break, with both hands operation, each turning angle is not easy to be too large, touch the ground can be exposed, so as to avoid sprain and twist melon handle, each turn melon should be carried out in the same direction. A few days before the watermelon is ripe and harvested, the melon can be erected so that the fruit shape is round and the peel is well colored, otherwise, there is no sunlight and yellowish white, which not only affects the appearance of the fruit, but also the thickness of the pericarp is uneven, the fruit taste is light, and the quality is poor. The drying and covering of melons should be based on the principle of "drying when hours and covering when ripe". In the immature green pericarp, there is a large amount of chlorophyll, and the photosynthates produced are directly transported to the fruit to promote the accumulation of sugar, so it is necessary to sun when it is small. When the fruit is about to ripen, the chlorophyll in the pericarp gradually decomposes. Photosynthesis decreases, and the internal part of the fruit is mainly the transformation of organic matter, rather than production and accumulation. If it is directly illuminated by strong light, it is easy to cause sunburn, so when the fruit is about to mature, it should be covered with leaves.

8. Accelerated ripening of watermelon: when it needs to be put on the market in advance, ethephon (dichloroethyl phosphoric acid) can be used to accelerate ripening. The method of treatment is that when the fruit is large enough and not yet ripe (that is, 25 murmur29 days after flowering), each kilogram of watermelon is smeared with 200 mg ethephon solution before and after evening, a small amount of neutral soap powder can be added to the solution to increase adhesion, and it can be harvested and put on the market two days later. The treated fruit was supplied to the market 5 days earlier than the natural ripe fruit, and the quality was not decreased, but improved.

9. Pest control: the main diseases of watermelon are Fusarium wilt, anthrax, virus, powdery mildew, blight, and the main pests are small land tiger, aphid, red spider, Huangshou melon, melon maggot, leaf miner and so on.

① disease control: rotation for more than 4 years, disease-free seeds were selected, and seeds were soaked in 100-fold formalin solution for 30 minutes. The main methods for the prevention and control of fungal diseases: disinfect the diseased plants in time and burn them, and disinfect them with lime or 50% Dysenamine 400 times. At the initial stage of the disease, 50% Dysenamine 500 / 1000 times solution can be irrigated in the rhizosphere to control the disease. Popularize the root-changing technique of watermelon grafting. Apply mature organic fertilizer and increase the application of phosphorus and potassium fertilizer. During the growth of watermelon from May to July, 1000 times of topiramine, 500 times of carbendazim, 1000 times of zinc and 200 times of Bordeaux solution were used alternately every 7 to 10 days.

Prevention and control of ② pests: for small land tigers, melon maggots and Huangshou melons, ploughing and harrowing in early spring can be used to eliminate eggs, sweet and sour to trap moths to kill adults, and use 80-1000 times liquid of trichlorfon to irrigate roots or add a small amount of water to mix fresh grass and fried cake fertilizer. Red spider and leaf miner can spray 50% dimethoate 1000 times or 80% dichlorvos 1000-1500 times.

Harvest

After pollination, the early-maturing variety matured about 28 days, the middle-maturing variety matured about 32 days, and the late-maturing variety matured about 35 days. Intuitively judge that the tendrils near the melon turn yellow and the sunken navel becomes smaller. Note that when picking at high temperature, it can be picked 1-2 days in advance to prevent it from being sold in time after picking, resulting in excessive ripening and declining quality. The maturity of watermelon can be identified by calculation, seeing, listening, testing and other methods.

① calculation: watermelon from sowing to harvest for more than 100 days, early ripening for 30 days, late ripening for 35 days, the fruit has matured.

②: several tendrils withered near the ripe fruit, the hairs of the stalk disappeared, the pedicel was concave, the stripes of the fruit surface scattered, the skin was smooth and shiny, and the fruit powder receded.

③ listen: play melon with fingers, mature sound, otherwise crisp voice for raw melon.

④ test: determined by the specific gravity method, the specific gravity of mature melons is 0.9-0.95, and those who sink in clear water are raw melons; the melons that come out of the water are very overripe. Only a few melons with proper maturity have surfaced.

Planting method of watermelon

Watermelon is the main summer fruit in summer, the flesh is crisp and tender, sweet and juicy, rich in mineral salts and a variety of vitamins, is the largest fruit sold in summer and autumn in China. In order to improve the yield and quality, let's learn about the cultivation techniques of watermelon with Xiaobian.

Morphological characteristics of watermelon

The main results are as follows: 1. the root of root watermelon belongs to deep root system, the main root is more than 1 meter deep, and the lateral root extends 4-6 meters laterally. The main root group is distributed in 10-40 cm soil layer and has strong ability to absorb fertilizer and water. The ability of root regeneration is weak, and it is not easy to recover after injury. Direct seeding is often used in production. If seedlings are transplanted, we must pay attention to the protection of roots.

2, stem, leaf watermelon stem also known as vine, the main vine in front of 5-6 leaves upright growth, more than 30 cm continue to grow a certain length, because the mechanical tissue is not developed, can not support their own weight, will crawl ground growth. The branching ability of the stem is very strong, and it can germinate 3-4 grade lateral branches, but the lateral branches from 3-5 leaf axils of the main vine are more strong. Adventitious roots are easily produced on the stem nodes of watermelons. The method of pressing vines can promote the formation of adventitious roots, increase the absorption area, fix plants and prevent seedling rolling. The leaves are alternate, and there are deep, lobed, entire and other types.

3. Flowers, fruits, seeds watermelon flowers small yellow, monoecious, solitary in leaf axils. The early-maturing varieties gave birth to the first female flower at the sixth and seventh nodes of the main vine, while the middle and late-maturing varieties produced the first female flower after the tenth section. The number of internodes of female flowers is 7-9 nodes. A small number of bisexual flowers can appear in the peak flowering period, and the flowers open in the morning and close in the afternoon.

The fruit is oval, spherical, dark green, light green, or with black-green stripes or markings. The flesh of melon is red, yellow, white and so on. The seeds are black, white, or red. Watermelon can also be divided into big-seed watermelon, small-seed watermelon and seedless watermelon according to the size of its seeds. the 1000-seed type is 100g ~ 150g, the medium seed type is 40g ~ 60g, and the small seed type is 20g ~ 25g.

The growth cycle of watermelon

The whole growth period can be divided into four stages: germination stage, seedling stage, vine stage and fruit stage.

The main results are as follows: 1. The germination stage is from seed germination to cotyledon expansion, and the true leaf exposure is the germination stage. After the seedlings are unearthed, it is necessary to prevent overgrowth in order to promote the development of roots and leaves.

2. The seedling stage is from the exposure of true leaves to 5-6 leaves. The growth in this period is small, and good conditions should be given in cultivation to promote the differentiation of seedling roots and organs.

3. The trailing period begins from 5-6 leaves to the female flower blooming in the melon node. In this period, the growth rate is fast and the growth rate is large. In cultivation, it is necessary to promote the growth of stems and leaves and form certain nutrients. at the same time, it is necessary to control overgrowth and ensure the formation of flower organs.

4. The fruiting period is from the female flower in the node position to the exuberant growth of the fruit. It can be divided into three periods: fruit setting period, fruit growth peak period and fruit changing period.

The fruit setting period is from the opening of the female flower to the exuberant growth of the fruit. Photosynthate begins to be fed into the fruit. In cultivation, it mainly regulates the balance between vegetative growth and fruit development to ensure melon setting.

During the vigorous growth period, the fruit grows rapidly until the size of the fruit is basically fixed. In this period, the fruit has a large growth and absorbs the most nutrients, which is the key period for the formation of yield. Large fertilizer and water should be given in cultivation to promote the rapid growth of fruit.

The ripening period is basically fixed from the fruit size to the mature stage. In this period, the sugar content is transformed rapidly, and the appearance has the inherent color of the variety. In cultivation, premature senescence of stems and leaves should be prevented in order to ensure yield and quality.

Requirements of Environmental conditions for planting Watermelon

1. Temperature Watermelon likes warm, dry climate and is not cold-tolerant, the optimum temperature for growth and development is 24-30 degrees, the optimum temperature for root growth and development is 30-32 degrees, and the lowest temperature for root hair generation is 14 degrees. Watermelon needs a large day-night temperature difference in the process of growth and development, and a large day-night temperature difference can cultivate high-quality watermelon.

2. Water watermelon is resistant to drought and humidity, and when it is overcast and rainy, the humidity is too high, it is susceptible to disease, the yield is low and the quality is poor.

3. Light watermelon likes light. Under the condition of sufficient sunshine, the yield is high and the quality is good.

4. Nutrient watermelon has a long growth period and high yield, so it needs a lot of nutrients. Every 100kg watermelon needs to absorb 0.19kg of nitrogen, 0.092 kg of phosphorus and 0.136 kg of potassium. However, there are obvious differences in the amount of nutrients absorbed by different growth stages, accounting for 0.01% in the germination stage, 0.54% in the seedling stage and 14.6% in the vine stage. The fruiting period is the most vigorous period for watermelon to absorb nutrients, accounting for 84.8% of the total nutrient content. Therefore, with the growth of the plant, the fertilizer requirement of watermelon gradually increased, and reached the maximum value when the fruit grew vigorously.

5. the adaptability of soil watermelon is strong, and the sandy soil with loose soil, deep soil layer and good drainage is the best. Like weak acid, PH5-7.

Cultivation techniques of watermelon

I. suitable time for sowing

The open field cultivation of watermelon is the cultivation without protective equipment. Generally speaking, the local final frost has passed, and the suitable time for sowing in the open field is when the ground temperature is stable at about 15 ℃. The best time for sowing should also be determined according to the variety, cultivation season, cultivation mode and consumption season. Generally sowing and raising seedlings in mid-and late-March, planting in mid-and late-April, harvesting and listing in late June; sowing in the first and middle of July and harvesting in late September.

2. Apply sufficient basic fertilizer for soil preparation

The cultivation of watermelon should choose the land with loose soil, deep soil layer, fertile soil, good drainage, sufficient light and western sun; watermelon field is not suitable for continuous cropping and should be rotated every 4-5 years. Otherwise, the Fusarium wilt is serious; the previous crops such as rice and corn are the best, followed by potatoes, cabbages and other vegetable crops, but the watermelon disease is serious and should not be selected.

Melon fields must be ploughed deeply, preferably in winter. In the land that has been deeply ploughed or has a deep ploughing foundation, drainage ditches are opened around, ditches are opened according to the cultivated row spacing of 2.4-3.0 meters (0.5 meters wide), and basic fertilizers are applied on one side of the border. 2500-3000 kg of farm manure is applied per mu, 15 kg of phosphate fertilizer, 20 kg of 45% compound fertilizer, 2 kg of borax and 1 kg of zinc fertilizer are applied. In order to control underground pests, a small amount of crystal trichlorfon can be mixed with base fertilizer. Cover the basal fertilizer ditch, form a melon ridge and finally cover the plastic film, waiting for sowing or transplanting. When opening the box, it should be noted that the box line is perpendicular to the spring and summer wind direction, and the wind first blows into one side of the box surface to apply basic fertilizer, so that the melon vine is consistent with the wind direction after planting.

Third, soaking seeds to accelerate germination

1. Soak the seeds in the sun for 1 day before soaking the seeds, soak the seeds in warm water that is not hot (about 30 ℃) for 6-8 hours, then remove the mucous membrane of the seed coat by wrapping the seeds with a towel or coarse cloth. In order to prevent Fusarium wilt, soak the seeds with 1000-fold solution of methyl topiramate for another 4 hours, the general soaking time is 12 hours, and the seed coat can be softened and rinsed with clean water to prepare for germination.

2. To accelerate germination, put the soaked seeds flat on a wet towel, cover the seeds with a layer of wet towels, and place them in an environment of 30-35 degrees. After 72 hours, they basically come out, and 85-90% of them can be sown.

4. Sowing or transplanting

1. A shallow trench or hole with a depth of 8 cm ~ 10 cm was opened on the melon ridge near the application of basic fertilizer, and the plant spacing was 45-50 cm. 1-2 seeds were sown in each hole, and the soil was covered with 2 cm ~ 3 cm (after being watered once in drought). Those who accelerate germination and direct sowing can emerge after 2-3 days; generally use seed 150 g ~ 200 g per mu.

2. Seedling transplanting seedling age 30-35 days, melon seedlings 3 leaves and 1 heart began to transplant, plant spacing 45-50 cm, about 450-500 trees per mu, and fixed root water after transplanting.

V. Field management

1. Middle ploughing and drainage ploughing begins after sowing or planting seedlings, which is generally carried out by the combination of interseedling, loosening soil and soil cultivation. Watering at the seedling stage should be less, and attention should be paid to "squatting seedlings" to facilitate root growth. When the vine is 30 centimeters long, it is necessary to apply heavy fertilizer and then cultivate the soil. Watermelon has large fruit, high yield and large water demand. Irrigation should be paid attention to in dry land cultivation, while drainage is particularly important in paddy field cultivation. It is emphasized that the drainage ditches around the border and field should be connected with each other, and there is no stagnant water in the field after rain, which is the basis to ensure the high and stable yield of watermelons. Stop irrigation 6-8 days before fruit ripening to promote sugar transformation and increase sweetness.

2. The basic principles of topdressing melon field are as follows: light application of seedling fertilizer, first promotion and then control, skillful application of vine fertilizer, and heavy application of expanded melon fertilizer after sitting on the young fruit.

① fertilizer promoting seedlings is generally applied within one week after transplanting or direct seeding seedlings at 4-5 leaf stage, and a small amount of available fertilizer is applied when the base fertilizer is insufficient or the fertilizer effect of the base fertilizer has not been brought into full play. Generally, each plant is applied 8 grams of urea (or 20 grams of ammonium sulfate) and covered with soil after ditching and fertilization.

② trailing fertilizer can be carried out before and after extending the vine. Generally, when the melon seedlings grow to 40-60 cm, urea 10-12 kg per mu, calcium superphosphate 8 kg, potassium sulfate 13 kg per mu, or 45% potassium sulfate ternary compound fertilizer 18-22 kg per mu, 25 cm 30 cm from the melon root or between the two plants, the ditch depth is 10 cm 15 cm. After application, cover soil and water to promote the absorption of fertilizer.

③ expanded melon fertilizer is the period when watermelon needs the largest amount of fertilizer in its lifetime. When the watermelon eggs are large, the root system is covered with the whole border, and many melon farmers will apply expanded melon fertilizer at this time. Because the hole fertilizer is too concentrated, it will burn out the roots around the fertilizer application point, and it is not conducive to the rapid decomposition and transformation of fertilizer, which is quite different from the characteristics of large fertilizer and water, quick and comprehensive fertilizer in watermelon expansion period. Therefore, it is best to use human and animal manure water and dissolved chemical fertilizer for watermelon fertilizer. When the watermelon egg is large, the circle about 30-45 cm from the root base of the melon (the extension side of the key melon vine) is poured with dung water plus compound fertilizer and urea, and the melon farmers without manure are mixed with water after dissolving with compound fertilizer 8 kg, urea 4.5 kg and potassium sulfate 5 kg. The concentration of expanded melon fertilizer should be light, and water should be used to adjust fertilizer, so that the fertilizer can play a role quickly in a short time, especially when the soil is drier. Foliar fertilizer spraying was carried out in the later stage, and 0.4% potassium dihydrogen phosphate solution was sprayed every 7-10 days for a total of 2-3 times.

3. Pruning watermelon has luxuriant vines and leaves. If the growing vines are allowed to overlap each other, it will not only affect close planting, but also delay melon fruiting. Watermelon pruning methods generally have single vine, double vine and three vines and so on. Single vine pruning leaves only one vine per plant. The method of removing all the other lateral vines is simple, with more plants per unit area and more melons, but less leaves per plant, fruit is not easy to grow, yield and quality are low. Double or three-vine pruning generally leaves the main vine, when the main vine grows to more than 30 cm, double-vine pruning is to leave a strong side vine at the base, three-vine pruning leaves two strong side vines as auxiliary vines or reserve vines, and the rest of the side vines are removed; double-vine pruning is often used in production. When pruning watermelons, one should pay attention to timely pruning. Generally, when the length of the main vine is 40-50 cm, the lateral vine is about 15 cm, and then every 3-5 days; second, no matter which pruning method is adopted, it is required to be carried out seriously before fruit setting, and generally no longer pruning after fruit setting, so that there are more branches and leaves to provide nutrition for fruit growth. When the fruit begins to expand rapidly, the heart can be removed in order to prevent the vegetative growth from becoming too prosperous.

4. Press the vine when the vine is 30 cm long, it should be adjusted to make its distribution uniform, and press the vine with a lump of soil on the node to promote the production of adventitious roots, fix the leaf vine, prevent each other from shading each other and being damaged by the wind, and then press every 5 to 6 knots until the vine leaves grow all over the border. There are two ways to press the vine: open pressure and dark pressure. In rainy areas, the soil moisture is high, in order to prevent rotten vines, it is not necessary to bury all the melons and vines in the soil, only the soil blocks are pressed on the nodes, and the internodes are still exposed to the ground, which is called "open pressure". In order to promote the occurrence of adventitious roots in dry areas with less rain, all melons and vines should be buried in the soil as "secret pressure". In order to prevent breaking the crisp tender melon vines, pruning and pressing should be carried out in the afternoon. No matter which pressure method is used, it should be determined according to the growth of the plant. Strong growth should take heavy pressure, diligent pressure, weak growth of light pressure, less pressure. Generally, it is pressed once every 5-6 knots, and two places are pressed before and after each melon. Leave 2-3 leaves before and after leaving the female flowers without pressure, in order to prevent stagnant water rotten melons, or melons grow up to be restrained.

5. Artificial pollination watermelon is a cross-pollinated crop that relies on insects as a vector. In rainy weather or less insect activity, it will affect the spread of pollen and it is not easy to set fruit. In order to improve the fruit setting rate and realize the ideal fruit setting position, artificial pollination should be carried out.

① female flowers should be pollinated with well-developed female flowers on the main vine and lateral vines. The flowers with thick bud stalk, hypertrophy of ovary, normal shape, bright green and glossy color are easy to set fruit and grow into high-quality melons after pollination. The female flowers on the side vines are used as reserve melons.

② pollination time the flower of watermelon began to loosen at 5 ~ 6 o'clock in the morning, and the physiological activity was the most exuberant at 8 ~ 10:00, which was the best time for pollination. In cloudy days, the time of pollination was postponed to 9 ~ 11:00 because of late flowering.

③ pollination method uses fresh male flowers which are open and pollinated on the same day, squeeze the petals toward the pedicel with hands, and then point the stamens of the male flowers at the stigma of the female flowers and dip them gently. One male flower can give 2 to 3 female flowers.

6. The second and third female flowers are generally left to bear melons. Early-maturing varieties can reserve the first to third female flowers, after sitting, according to the "two, one, three" order to retain a melon. The second to fourth female flowers can be reserved for middle and late maturing varieties, and one melon will be selected after sitting down in the order of "three, two, four". If the melons on the main vine are not seated, the melons should be kept in the same order on the side vine. It is appropriate to leave 1 melon per plant.

7. Watermelon fruit nursing in the stage of watermelon flowering, fruit setting and fruit development, careful care of fruit is also the key link to improve the yield and quality of watermelon. Nursing measures include protecting melon, cushion melon, turning melon, vertical melon, sun melon and cover melon and so on.

From the female flower to before and after fruit setting, the epidermis of ovary and young melon are very delicate and vulnerable to wind, insect bite and mechanical damage. at this time, paper bags and plastic bags are used to cover the young melons. When the fruit grows to 1-1.5 kg, break the soil under the melon and cover it with grass or fine sand, that is, the melon. Turning the melon means constantly changing the landing position of the fruit, so that the surface of the melon is evenly exposed to light, the skin color is the same, and the maturity of the flesh is uniform. Turning melon is generally carried out in the middle and later stage of expanding melon, turning once every 5-6 days, can turn 2-3 times, turn melon should be reduced in sunny afternoon stalk moisture, not easy to break, with both hands operation, each turning angle is not easy to be too large, touch the ground can be exposed, so as to avoid sprain and twist melon handle, each turn melon should be carried out in the same direction. A few days before the watermelon is ripe and harvested, the melon can be erected so that the fruit shape is round and the peel is well colored, otherwise, there is no sunlight and yellowish white, which not only affects the appearance of the fruit, but also the thickness of the pericarp is uneven, the fruit taste is light, and the quality is poor.

The drying and covering of melons should be based on the principle of "drying when hours and covering when ripe". In the immature green pericarp, there is a large amount of chlorophyll, and the photosynthates produced are directly transported to the fruit to promote the accumulation of sugar, so it is necessary to sun when it is small. When the fruit is about to ripen, the chlorophyll in the pericarp gradually decomposes. Photosynthesis decreases, and the internal part of the fruit is mainly the transformation of organic matter, rather than production and accumulation. If it is directly illuminated by strong light, it is easy to cause sunburn, so when the fruit is about to mature, it should be covered with leaves.

8. When the ripening of watermelon needs to be put on the market in advance, ethephon (dichloroethyl phosphoric acid) can be used to accelerate ripening. The method of treatment is that when the fruit is large enough and not yet ripe (that is, 25 murmur29 days after flowering), each kilogram of watermelon is smeared with 200 mg ethephon solution before and after evening, a small amount of neutral soap powder can be added to the solution to increase adhesion, and it can be harvested and put on the market two days later. The treated fruit was supplied to the market 5 days earlier than the natural ripe fruit, and the quality was not decreased, but improved.

9. The main diseases of watermelon controlled by diseases and pests are Fusarium wilt, anthrax, virus, powdery mildew and blight, and the main pests are small land tiger, aphids, red spiders, yellow melon, melon maggots, leaf miner and so on.

The control of ① disease was carried out for more than 4 years, and the disease-free seeds were selected. The seeds were soaked in 100-fold formalin solution for 30 minutes. The main methods for the prevention and control of fungal diseases: disinfect the diseased plants in time and burn them, and disinfect them with lime or 50% Dysenamine 400 times. At the initial stage of the disease, 50% Dysenamine 500 / 1000 times solution can be irrigated in the rhizosphere to control the disease. Popularize the root-changing technique of watermelon grafting. Apply mature organic fertilizer and increase the application of phosphorus and potassium fertilizer. During the growth of watermelon from May to July, 1000 times of topiramine, 500 times of carbendazim, 1000 times of zinc and 200 times of Bordeaux solution were used alternately every 7 to 10 days.

② pest control to small land tiger, melon maggot, Huangshou melon can be used in early spring ploughing and harrowing to kill eggs, sweet and sour to trap moths to eliminate adults, with 80-1000 times liquid of trichlorfon to irrigate roots or add a small amount of water to mix fresh grass and fried cake fertilizer. Red spider and leaf miner can spray 50% dimethoate 1000 times or 80% dichlorvos 1000-1500 times.

6. After harvest and pollination, the early-maturing varieties matured in about 28 days, the middle-maturing varieties matured in about 32 days, and the late-maturing varieties matured about 35 days. Intuitively judge that the tendrils near the melon turn yellow and the sunken navel becomes smaller. Note that when picking at high temperature, it can be picked 1-2 days in advance to prevent it from being sold in time after picking, resulting in excessive ripening and declining quality.

How to identify the maturity of watermelon

The main results are as follows: 1. It is calculated that the watermelon is ripe for more than 100 days from sowing to harvest, 30 days for early ripening and 35 days for late ripening.

2. The tendrils withered near the ripe fruit, the hairs of the stalk disappeared, the pedicel was concave, the stripes scattered, the skin was smooth and shiny, and the fruit powder receded.

3, listen to play melon with your fingers, mature and voiced, on the contrary, the voice is crisp for raw melon.

4. Measured by the specific gravity method, the specific gravity of mature melons is 0.9-0.95, those who sink in clear water are raw melons, and the melons that come out of the water are very overripe. Only a few melons with proper maturity have surfaced.

The cultivation of watermelons is still very fastidious, but also to pay attention to methods, to learn from the winners of their experience and methods, in order to avoid detours, grow high-yield and high-quality watermelons. The market demand for watermelon is very large, so the planting prospect of watermelon is still very broad!