Key points of watermelon seedling cultivation in greenhouse in winter

1. Improving the heat preservation and heating measures of the seedling shed, using the new high fat film instead of polyethylene film, the heat preservation and performance can be greatly improved, and the greenhouse temperature can be increased by 1 ℃ ~ 2 ℃. Temporary heating equipment such as fire wall or heating furnace should be installed in the greenhouse. Artificial warming should be carried out when necessary.

2. The seeds of watermelon and rootstock were treated at low temperature, and the seeds were soaked with new high-fat membrane to enhance the cold resistance of seedlings. The seeds to be germinated after soaking were placed in a freezing environment of about 0 ℃ for 24 hours, and then germinated under the condition of suitable temperature. when the seeds were white, they were treated with-1 ℃ for 12 hours a day. Transfer to 18 ℃ treatment for 12 hours for a total of 3 to 5 days, and then accelerate germination under suitable temperature conditions.

3. Strengthening the management after grafting within 1 week after grafting is the stage of wound healing, and the greenhouse temperature should be kept at 20 ℃ ~ 30 ℃. When the night time is less than 18 ℃, artificial spraying should be carried out to increase the temperature of the new high fat film. The grafted seedling bed should be strictly sealed for 3 to 6 days to maintain the relative temperature in the bed. It should be completely shaded in the first 3 days, only through weak scattered light, gradually see light on the 4th day, gradually ventilate after 6 days, remove the shade and increase ventilation volume after 7 days. Make the grafted seedlings adapt to the normal seedling bed environment.

4. strengthening the management of disastrous weather, and the management during severe weather such as overcast, rain and snow, strong cold current and so on is an important link in the success or failure of seedling breeding. Pay attention to listen to the weather forecast and take measures to keep warm before the cold spell comes. Two layers of film must be covered with grass grass in rainy and snowy days. In continuous cloudy days, increase the light as much as possible without freezing damage. If the bed temperature drops after uncovering, the grass should be opened and covered before 3 p.m. If the bed temperature drops slightly, it can be covered with the cover. Do not not uncover for a few days, when there is rain and snow, cover the grass with the break between the rain and snow. If the light is insufficient for a long time, you can use fluorescent lamps to make up the light manually. Uncover after a long overcast should be carried out slowly, otherwise it is easy to cause flashing seedlings or even falling seedlings. If it is found that the seedlings are withered, they should be covered with shade immediately and wait for the melon seedlings to return to normal. Repeat this several times until it doesn't wither. Then uncover all the grass grass, and then enter the normal management. Sun Shuli