Cultivation Techniques of Watermelon in Green Food Greenhouse in Early Spring

Cultivation techniques of watermelon in early spring in green food greenhouse

1 selection of place of production

The producing area should choose areas with no industrial and mining areas, non-urban transportation lines, no "three wastes" pollution, good ecological environment and clean water sources within the range of 5 km. Mainly considering the topography, soil quality, stubble and so on, it is required that watermelons have not been planted within 3 years to prevent repeated cropping and reduce the influence of soil pathogenic bacteria. Local people should pay attention to the spring flood to prevent waterlogging. Environmental selection should meet the requirements of "Environmental quality of Green Food producing areas" (NY/T391).

2 Variety selection and seed treatment

Select early-maturing varieties with high quality, such as 84-24, Jingxin, Nabit, early spring ruby and so on. Sow the seeds before sowing. Sunny days should be selected for seed drying for 1 day. Then the seeds were soaked in warm water. The suitable water temperature is about 55 ℃, the soaking time is controlled between 15 min and 30 min, and the soaking time is stirred evenly, then the seeds are soaked in room temperature water for 2 hours, and then germinated. After soaking the seeds, wash and dry the seeds, wrap them with wet gauze, and place them in the environment of 28032 ℃ to accelerate germination. Usually, the seeds can be exposed after 24 hours and 30 hours, and then the seeds will be placed in the environment of 1520 ℃ for 12 hours. At this time, the seeds can be sown.

3 sowing and raising seedlings

3.1 preparation of nutritious soil

Greenhouse cultivation usually begins to raise seedlings from the end of January to the beginning of February. When selecting watermelon seedling land, the plots with shelter from the wind and sun, high dryness and convenient drainage and irrigation should be selected. The nutritious soil needs to be prepared more than one month in advance, and the paddy soil that is fertile, loose, moist and has not been planted with melons for more than 5 years is selected, and an appropriate amount of 0.2% compound fertilizer, 5% rotten feces and urine, 0.2% calcium superphosphate and 0.1% potassium sulfate are added, which can be used after being covered with film for more than 15 days.

3.2 sowing

The watermelon seedling shed should be covered with plastic film about 7 days before sowing, and the bottom water should be poured 2 days before sowing, so that the temperature of sowing should be above 25 ℃. Watermelon sowing is usually carried out in the afternoon on a sunny day, 1 seed per bowl, and the seeds are covered with soil thickness of 0.5 cm, and then an arch shed is set up to keep warm.

3.3 Seedling stage management

In order to promote the emergence of watermelon, the temperature should be on the high side before emergence, and the temperature should not be lower than 22 ℃ in daytime, 28-30 ℃ in daytime, and 18-25 ℃ at night. When the emergence rate of watermelon reaches 30% to 40%, the plastic film should be opened in time, and the arch shed should be ventilated in time to appropriately reduce the temperature. At this time, the temperature can be about 25 ℃ in the daytime and below 15 ℃ at night, and the temperature can be increased by appropriate heating measures [4].

Watermelon has a large demand for water before emergence, so the soil of the seedling bed should be kept moist. After emergence, the first real leaf should not be watered too much, and the soil should be watered thoroughly when the soil is white. For seedling topdressing, there is no need for topdressing normally. If the plant grows weakly before transplanting, nutrients can be replenished by topdressing 0.2% urea and potassium dihydrogen phosphate.

Watermelon is a light-loving plant. Therefore, sufficient light should be ensured at the seedling stage, and the arch shed can be removed to supplement the light when the weather is clear, and artificial light can be used to make up for the light in case of continuous overcast and rainy weather.

The standard of strong seedling: the watermelon seedling with developed root system, sturdy plant, 5 ~ 6 leaves, no diseases and insect pests and about 50 days old can be regarded as strong seedling.

(4) soil preparation and fertilization to make beds

The melon field was required to turn deep ridges before winter. 15 days before planting, 225 kg/hm2 of potassium sulfate compound fertilizer, 2250 kg/hm2 of rapeseed cake and 15 t/hm2 of mature farm manure were applied in the furrow and covered with soil. The watermelon cultivation plot can be deeply turned over and cultivated in deep trench and high border in winter, and the border surface should be about 3 m, with tortoise back shape, deep trench in the middle and no ditch on both sides. The temperature of watermelon was increased by buckling shed more than 7 days before planting.

5 suitable time for colonization

For early-maturing cultivation in spring, it is usually appropriate to choose strong seedlings with a seedling age of about 50 days. Reasonable close planting, one row per row, the plant spacing of 3 vines is 50 ~ 80 cm, and the density is about 4500 plants / hm2. Planting method: watering enough water one day in advance, after opening the hole, take out the soil from the nutrition bowl and take out the seedlings for planting. After planting, the seedlings were compacted with soil and poured through the root water.

6 field management

6.1 temperature and humidity management

In order to improve the survival rate, ventilation should not be carried out within 3 days after planting. In the later stage, when the daytime temperature is in the range of 30-35 ℃, it can be properly ventilated and humidified. After the watermelon enters the expansion period, the temperature in the greenhouse should be kept above 30 ℃ to promote the rapid expansion of watermelon. When the watermelon grows to the size of commercial melon, the temperature and humidity can be reduced appropriately in order to improve the quality of watermelon.

6.2 Fertilizer and Water Management

Watermelon has little demand for fertilizer and water at flowering stage. When it enters the fruit-setting stage, it is necessary to increase the supply of fertilizer and water to promote fruit expansion and achieve the purpose of high yield and high yield. Generally, the potassium sulfate compound fertilizer was applied for 225 kg/hm2, then 75 kg/hm2 for each harvest and about 375 kg/hm2 for the whole stubble. Keep the field moist during the expansion period, but do not accumulate water, and control moisture 7 days before harvest [6].

6.3 pruning and pressing vines

When watermelons are growing vigorously, they should be pruned properly, usually in the form of two-vine or three-vine pruning. In order to ensure that the main vines and individual stout lateral vines are nutritious, the rest of the lateral vines should be removed.

6.4 Fruit setting and melon protection

The second and third female flowers of the main vine are used to set fruit, usually in the 15th ~ 20th section. In order to improve the fruit-setting rate of watermelon, artificial pollination can be adopted, and it is suitable to work with 8-meter-00-10-meter. When the watermelon fruit grows to the size of an egg, the fruit can be thinned in time, and the small, deformed fruit, disease and insect fruit will be removed, leaving a young melon with a big head, straight and thick stalk and furry hair.

7 Prevention and control of diseases, pests and weeds

For watermelons in early spring in greenhouse, diseases and insect pests should be dominated by agricultural control, supplemented by biological control and chemical control. Agricultural control can carry out flood-drought rotation for more than 3 years or dry land rotation for more than 5 years; timely clean the countryside, prune and branch, remove diseased leaves and old leaves, timely ventilation and light, reduce air humidity, increase light, improve ecological conditions, and improve plant disease resistance; remove weeds, reduce the number of disease sources, and reduce the occurrence of diseases and insect pests. Pest control should meet the requirements of NY/T393 "guidelines for the use of Green Food pesticides".

In the prevention and control of leaf spot and downy mildew, 50% carbendazim wettable powder was sprayed once at the early flowering stage. In the prevention and control of anthracnose, downy mildew and powdery mildew, 80% mancozeb wettable powder 1000 times can be sprayed once. In the prevention and control of vine blight and Fusarium wilt, 99% dimethrin 4000 times solution was sprayed once. The main method of pest control is physical control, such as anti-insect net, sticky aphid board, anti-pest lamp and so on. The main purpose of chemical control is to control aphids. In April, 10% imidacloprid wettable powder was sprayed once. In weed control, plastic film mulching can be used to control weeds by artificial means.

8 timely harvest

The harvest of watermelons in early spring in greenhouse should depend on specific varieties, sowing time and transportation distance. Sowing around January in early May can be harvested on the market; if sold locally, watermelons can be harvested when they grow to 9: 10, or if shipped to other places, they can be harvested in advance when watermelons are ripe at 8: 9.