The latest course of efficient cultivation techniques and methods of seedless watermelon

The growth of seedless watermelon is roughly the same as that of ordinary watermelon, so its cultivation technique is similar to that of ordinary watermelon, but seedless watermelon also has many unique characteristics, such as low seed germination rate, low seedling rate, slow growth in the early stage, exuberant growth in the middle and later stage, pollen abortion, low natural fruit setting rate and so on. Therefore, the corresponding technical measures should be taken in cultivation and management in order to obtain high yield and high efficiency.

Melon field preparation

Although seedless watermelon is not strict on soil, it is still necessary to create a better suitable environmental condition for its high yield in terms of high yield and high quality. Because seedless watermelon has the characteristics of continuous cropping, waterlogging, drought and developed root system, the fields with high dryness, sufficient sunshine, deep soil layer, good permeability and convenient drainage and irrigation should be selected to ensure the normal growth and development of seedless watermelon. After thawing in early spring, rake fine and level the melon field, dig the melon ditch according to the predetermined row spacing, the ditch is 30cm of depth and width. Irrigate enough moisture at the bottom, apply 4,000 kilograms of high-quality rotten farm manure per mu, 50 kilograms of nitrogen, phosphorus and potassium ternary compound fertilizer, or 50 kilograms of special fertilizer for watermelons, spray phoxim disinfection, and then cover the border with film. This work should be carried out 7 days before planting.

Sowing and raising seedlings

The temperature requirement of seed germination and seedling emergence of seedless watermelon is higher than that of seeded watermelon, the growth before the two-leaf stage is slow, and the cold resistance of seedlings is weak, so it is generally produced by seedling transplanting and direct seeding cultivation in some places.

1. Nursery bed preparation: establish a seedbed in a greenhouse or a small arch shed. The seedbed is generally 1.2 meters wide, 15-20 centimeters deep and 8-12 meters long. On the north side of the seedling bed in the small arch shed, the wind barrier is made of sorghum or corn straw. Nutritious soil is generally prepared according to the proportion of four parts of original soil and one part of rotten barnyard manure, adding appropriate amount of methyl thiophanate and trichlorfon to disinfect, fully mixed, sifted, loaded into a nutrition bowl, covered with plastic film to increase temperature.

2, soaking seeds to promote germination: first, pour boiling water and cold water into a clean basin in a ratio of two to one, set the temperature to about 55-60 ℃, put the seeds in and stir quickly until the temperature drops below 40 ℃, stop stirring, and soak the seeds for 1-1.5 hours. Remove the sticky material from the surface of the seed by scrubbing it repeatedly. Because the seed embryo of seedless watermelon is incomplete, the seed coat is thick, and it is difficult to germinate, so the shell-breaking treatment should be taken before germination to improve the germination rate. Generally use teeth to gently open the suture line of the seed navel 1/3, you can also use nail Clippers to open the seed navel, be careful not to damage the seed embryo. Do not open the hilum too much, so as not to peel off the seed coat in the process of budding. The chewed seeds are rolled with a dry wet cloth and placed in a 33-35 degree incubator to germinate. After 20 Murray for 24 hours, the budding seeds are picked out, and the remaining seeds continue to germinate. In rural areas, hot kangs, electric blankets and stoves are generally used to promote germination, but the temperature and humidity must be controlled to ensure the smooth germination of seeds. Special attention should be paid to the process of budding:

① maintain appropriate humidity, do not add water or leaching at will, prevent excessive moisture in germination bed and seeds, cause rotten seeds or rotten buds, and do not make seedbed humidity too low to prevent seeds from drying.

② maintains a relatively constant temperature to prevent drastic temperature changes, drastic cooling or excessive temperature will lead to the loss of germination ability of germinating seeds.

③ keep the seeds ventilated and do not germinate in tightly sealed, airtight containers or plastic films.

3. Sowing: it is suitable for North China to sow seeds at the end of March and the beginning of April, and water the soil moisture thoroughly the day before sowing. Sowing should be carried out under sunny and windless conditions. When sowing, use a small wooden stick to make a small hole in the center of each nutrition bowl, then place the seeds flat in the seedling soil, make the buds down close to the hole wall, and sow one seed at each nutrition bowl point. Cover it with sifted fine soil in time, and the thickness should not exceed 1 cm. Sowing starts from one side of the seedbed and covers the film while sowing.

4. Seedbed management: the seedling stage of seedless watermelon is generally about 30 days. According to the law of germination and seedling growth, seedbed management can be divided into three stages: the first stage, from sowing to unearthed cotyledons, the focus of management is to raise the temperature and "take off the cap". The temperature is kept at 30-35 ℃ during the day, the grass curtain is properly covered to prevent cold at night, and the ground temperature is kept at 18-20 ℃ at night. Unearthed seedless watermelon with shell is a common phenomenon in seedling rearing. When the seed coat is soft, gently remove the seed coat with both hands or tweezers every morning, and be careful not to damage cotyledons and young stems. In the second stage, from the micro-expansion of cotyledons to the exposure of the first true leaf, the focus of management is to control moisture and lower temperature to prevent high temperature from growing to form tall seedlings. During this period, the temperature should be controlled at about 25 ℃ during the day and 15-20 ℃ at night. If the temperature is too high, the film mouth should be opened for ventilation and cooling. The position of ventilation is generally on the leeward side, and ventilation is generally from 10 am to 4 pm. In the third stage, the seedlings break their hearts to 2-3 true leaves, and the management focuses on temperature and humidity. The seedling bed temperature was appropriately raised to 25-30 ℃, and the ventilation time was appropriately prolonged. The seedlings were exposed 3-5 days before transplanting to enhance the stress resistance of seedlings. Humidity is strictly controlled in the seedling stage, as long as there is sufficient water at the bottom of the seedling bed, do not water as far as possible, if there is a shortage of water, you can sprinkle the kettle in the sunny morning to maintain a certain degree of humidity. Water once in the afternoon before transplanting to prevent root damage when transplanting. In addition, timely attention should be paid to the removal of weeds and spraying to control stunting diseases and various pests.

5. Pollination varieties: the pollen of male flower of seedless watermelon has poor development and almost no vitality, which can not stimulate the ovary of female flower. Only by means of pollen stimulation of ordinary watermelon can it grow into seedless watermelon. Pollination varieties should be selected from the local main varieties of seeded watermelon, the skin color of fruit should be different from that of seedless watermelon, in order to identify, the ratio of seedless watermelon to seedless watermelon is generally 9-10: 1. In order to meet the flowering stage of pollinated varieties and seedless watermelons, pollinated varieties should be sowed late for 5 days.

The seedling raising technology of seedless watermelon is the key technology in the production of seedless watermelon. only by accurately grasping the key links in the process of raising seedlings can we ensure that the seedlings are strong and lay a good foundation for high yield and income.

Field planting

The planting time of seedless watermelon is suitable after the final frost, and the average daily temperature is more than 15 ℃. In North China, it is generally from the end of April to the beginning of May. The seedling age of 2-3 leaves and 1 heart is better. Planting should choose sunny and windless weather, and pay attention to listen to the weather forecast to prevent gale cooling weather. Planting density, the northern region generally planted 650-750 plants per mu, plant spacing of about 70 cm, row spacing of 1.4-1.6 meters. The planting method is to punch holes in the middle of the high ridge according to the planned plant spacing, and if necessary, spray to control soil pests or apply a small amount of hole fertilizer. The seedlings will be planted into the hole, the depth is slightly lower than the ground, cover the soil to make the nutrition bowl closely combined with the soil, watering and stabilizing the seedlings, after the underwater infiltration, seal the film holes with fine soil.

Field management

Seedless watermelon grows slowly at seedling stage, so early management should promote early development, control fertilizer and water after vine extension, prevent overgrowth, create conditions for fruit setting, and choose better nodes for artificial pollination.

1. Fertilizer and water management: water management, seedless watermelon is watered at least 3 times during the whole growing period, the leaves of watermelon increase after vine extension, sunshine time is long, water demand is increased, and "vine water" should be watered once. When the young melon grows to the size of the fist, pour the expanded melon water well to ensure the yield and quality of watermelon and normal growth and development. In the future, we can decide whether to water or not according to the climate and soil moisture at that time, and stop watering a week before harvest. Topdressing, watermelon is a fertilizer-loving crop, rational fertilization is one of the important measures to ensure high quality and high yield of watermelon. The general principle is: careful application of seedling fertilizer, skillful application of vine fertilizer, re-application of expanded melon fertilizer. Topdressing is mainly quick-acting fertilizer. In the case of sufficient base fertilizer, the non-sandy soil generally does not apply seedling fertilizer, but usually carries out two times of topdressing, and the extension fertilizer should be mainly nitrogen fertilizer, supplemented by potassium fertilizer and quick-acting fertilizer to promote the vegetative growth of watermelon. in order to ensure the formation of developed roots and sufficient leaf area needed for high yield of watermelon, generally 8 kg of urea and 5 kg of potassium sulfate per mu. The second time is to apply quick-acting chemical fertilizer before the fruit expansion period, and the topdressing should be mainly potassium and nitrogen fertilizer, which is beneficial to the formation of fruit yield and the improvement of fruit quality. Generally, urea is 20-25 kg per mu, and potassium sulfate is 10 Murray 15 kg per mu. Water and fertilizer management should be reasonably controlled according to the local soil climatic conditions and the growth of melon seedlings, so as to achieve the combination of tracking and control, irrigation and drainage.

2. Pruning and pressing vines: seedless watermelons are generally pruned with double or three vines. Double vine pruning is to choose to stay in addition to the main vine, and select a strong side vine at the base of the main vine, and remove all the other side vines. In this way, the distribution of stems and vines is reasonable, the leaves are ventilated and transparent, and the ability of photosynthesis and disease resistance is enhanced, so as to increase yield and improve quality. Pressing the vine can fix the melon seedlings, prevent them from being turned over by the strong wind, and control the growth of the melon seedlings. When the main vine of the melon seedling grows to about 30cm, the melon seedling will be removed from the upright type, forcing the melon seedling to grow in the prescribed direction. Generally speaking, there are two ways to press the vine: open pressure and secret pressure. Open pressure refers to the use of clods or branches to fix melon vines on the ground; dark pressure is to shovel and flatten the soil, and the melon vines are buried in the ground. In general, the main vine is pressed for the first time at 40-50cm, and then pressed every 4 Murray 6 knots, requiring 2 Murray 3 times.

3. Artificial pollination: in order to ensure the fruit of female flowers at suitable nodes, artificial pollination must be carried out. The quality of the third female flower of the main vine or the second female flower of the lateral vine is the best and the yield is the highest. Pollination takes place at 7 am-10:00 every morning. When the watermelon blossoms in the morning, the newly opened male flowers are collected from the pollinated varieties, the petals are folded back to reveal the stamens, and then the stigma of the seedless watermelon female flower opened that day is gently dabbed for a week to pollinate evenly.

4. Fruit setting and leaving fruit: when the young fruit grows to the size of steamed bread, the fruit begins to expand rapidly, and the fruit is no longer falling at this time. The fruit with good node position and positive fruit shape should be selected in time, and one fruit should be left for each tree with double or three vines.

5. Pest control: pest control is a regular work of field management and an important part of high yield. The main diseases of seedless watermelon are vine blight, anthracnose, leaf blight and so on. 75% chlorothalonil 600 times solution, or 70% methyl thiophanate 500 times solution, or 70% Daimeng zinc 600 times solution should be sprayed in time, and used alternately. Stop spraying 7-10 days before harvest.

6. Cover melon: in the late growth stage of seedless watermelon, the plant gradually decays, and the leaves can not cover the sun effectively. Cover the melon with newspaper in time to prevent it from being damaged by the sun.

Timely harvest

Seedless watermelon takes about 35-40 days from flowering to fruit ripening. Moderately ripe fruits are good in color, juicy, sweet and refreshing, and should be picked in time.