How to grow watermelon in greenhouse

1, main technical requirements of watermelon in greenhouse

1. 1 Watermelon Variety Screening in Greenhouse

Watermelon varieties suitable for greenhouse cultivation in early spring require early maturity, high quality, easy fruiting, disease resistance, high yield and market demand. Through the summary in recent years, the varieties suitable for planting in Huxian area mainly include Jinmei Daguo, Supreme, Lido and so on.

1.2 Screening of Watermelon Rootstock Varieties in Greenhouse

Rootstock requires not only good and stable affinity with watermelon grafting, but also good disease resistance, which has no adverse effect on watermelon quality. Due to the high groundwater level in most parts of Huxian county, according to the observation in recent years, the gourd rootstock has poor resistance to acute wilt of watermelon, which is easy to cause incalculable losses, while the pumpkin rootstock is relatively good. So now Huxian basically uses pumpkin rootstocks as watermelon rootstocks. At present, the better rootstocks are: Zhuangsi, Pumpkin No.2, Pumpkin Changbai Board, etc.

1.3 watermelon seed treatment in greenhouse

Like watermelon seeds, rootstock seeds were soaked in warm water at 25℃ ~ 30℃ for 48 hours. After soaking, the seeds are washed with clear water for several times, rubbed repeatedly, and harmful substances on the surface of the seeds are washed away. Then, they are wrapped with fine cloth and placed in a constant temperature box at 27℃ ~ 30℃ to accelerate germination, or a thermometer is inserted and placed on a kang to accelerate germination. The length of accelerating germination is as good as that of just showing white.

2. The sowing date and method of watermelon in greenhouse.

2. 1 sowing date: the solar calendar is about 65438+February 20th in Huxian area.

2.2 Sowing method: Put the middle germ of the germinated rootstock seeds downward, and then cover it with 1.5-2cm floating soil (fine sandy loam). Generally speaking, watermelon seeds can germinate about 5 days after rootstock seeds are sown, and watermelon seeds can germinate in sandbox.

3. Transplantation method

3. 1 Grafting time: The cotyledons of rootstock seeds can be grafted after flattening, which is also the best time for grafting.

3.2 Grafting method: the top-inserting method is adopted, when grafting, the growing point of the rootstock is removed, a bamboo stick is inserted into the lower shaft of the cotyledon obliquely downward at 45 degrees along the direction of straight leaf connection, and the depth is 0.5- 1cm, then the top end of the bamboo stick reaches the cortex on the other side of the lower shaft of the cotyledon, and then the scion seedlings are taken out, placed on the index finger, cut with a blade at 45 degrees, and cut off.

3.3 Management of grafted seedlings: keep the temperature at 25℃ and the low temperature at 24℃, and keep it closed and ventilated for the first three days after grafting, so that the air humidity can reach saturation. One week before planting, the ground temperature drops to 15℃ ~ 13℃, the daytime temperature drops to 23℃, the nighttime temperature drops to 13℃, and the minimum temperature at night is not lower than 10℃, so that the seedlings are close to the ambient temperature after planting.

4. Planting watermelons in greenhouses

4. 1 colonial period

In recent years, due to the abnormal climate, the planting time has been generously postponed, generally from the end of February to the beginning of March in the solar calendar at the latest, that is, when the ground temperature 10cm passes stably 13℃.

4.2 Planting density

Generally, the row spacing is 3 meters, the plant spacing is 0.4 meters, and about 555 plants are planted per mu.

4.3 Colonial methods

Choose sunny weather, put the grafted seedlings without nutrition bowl into the planting hole, make the clods flush with the border surface, fill them around, enclose them, and water them by point watering (with bowls or scoops). When planting, pay attention to that the grafting knife edge is larger than lcm.

5. Fertilization of watermelon in greenhouse

5. 1 fertilization amount

Apply ternary compound fertilizer (n: p: k =15:15:15)15-25 kg per mu or apply a certain amount of biogas slurry downstream.

5.2 Fertilization method

Topdressing should be combined with watering. When the watermelon grows to the size of an egg, it should be combined with watering the melon to make it topdressing again.

6. Watermelon irrigation technology in greenhouse

After the survival of planting, if the water is insufficient, it should be watered once, which is called "slow seedling water"; When the seedlings grow to about 30cm, small water should be poured into the ditch, which is called "pumping rattan water". Watermelon should be watered slightly according to the soil moisture in the shed before flowering, and water should be controlled during flowering and fruit setting to prevent melon seedlings from being too prosperous, which will make fruit setting difficult and melting. After the fruit is set, when the watermelon grows to the size of an egg, water it with "swollen water". Water should be stopped 7 ~ 10 days before harvesting.

7. Field management of watermelon planting in greenhouse

7. 1 Pruning and pressing vines

The pruning method is three vines, and the pressing method is open pressing.

7.2 Artificial pollination

Artificial pollination is carried out at 7-9 am on the day when the female flower opens, and the pollen of the male flower that opens on the day of picking is smeared on the stigma of the female flower.

7.3 Select and keep the melon embryo

Set six leaves with watermelon: rootless melon; Do not leave extra-long melons; Don't leave two; Leave no deformed fruit; Leave no pests and diseases; No scratches.

7.4 Timely harvest

It usually takes 30 ~ 35 days for early-maturing watermelon to mature from fruit setting. It is necessary to calculate its maturity time and harvest it in time, which is conducive to improving yield and ensuring fruit quality.

8. Integrated pest control of watermelon in greenhouse

8. 1 Main pests and diseases

Seedling stage: cataplexy and cataplexy.

Growth period: anthracnose, epidemic disease, powdery mildew, Fusarium wilt.

Main pests during growth: aphids, red spiders and whiteflies.

What needs special attention is the maturity of watermelon: fleshy fruit (physiological disease fruit)

8.2 Prevention and control methods

① Agricultural control: select disease-resistant varieties. According to the main local pests and diseases and the cultivation season, select varieties with high resistance and multi-resistance.

② Physical control: hanging silver-gray film strips around the facilities to avoid aphids, or trapping and killing with insecticidal boards.

③ Chemical control: Nongkang 120 (broad spectrum), Wuyimen (Fusarium wilt control), agricultural streptomycin, liuyangmycin, avermectin, Iveden, etc.