How to Grow and Raise Watermelon Seedlings in Winter? Latest Technical Method Tutorial
Improve the insulation and heating measures of the seedling shed. Replace polyethylene film with polyvinyl chloride non-drip film; insulation and non-drip performance are greatly improved, and the shed temperature can be raised by 1-2 degrees. Temporary heating equipment such as a firewall or heating stove should be installed in the shed. Carry out artificial heating when necessary.
Subject watermelon and rootstock seeds to low-temperature treatment to enhance the cold resistance of the seedlings
Place the seeds that have been soaked and are about to be germinated in a freezing environment of about 0 degrees for 24 hours, then place them under suitable temperature conditions to germinate. When the seeds begin to show white, treat them at -1 degree for 12-18 hours each day. Then transfer to 18 degrees for 12-6 hours, for a total of 3-5 days, and then germinate them again under suitable temperature conditions.
Strengthen management after grafting
Within 1 week after grafting is the wound healing stage; keep the shed temperature at 20-30 degrees. When the nighttime temperature is below 18 degrees, artificial heating should be carried out. The grafted seedling bed should be strictly sealed for 3-6 days, maintaining a relative humidity of 100% in the bed. For the first 3 days, it must be completely shaded, with only weak scattered light allowed to pass through. On the 4th day, gradually expose to light; after 6 days, gradually ventilate; after the 7th day, remove the shading material and increase ventilation. This allows the grafted seedlings to adapt to the normal seedbed environment.
Strengthen management during severe weather
Management during severe weather such as continuous overcast, rain and snow, and strong cold waves is an important part of the success or failure of seedling raising. Pay attention to listening to weather forecasts and take insulation and heating measures before a cold wave arrives. During rain and snow, a second layer of film must be placed over the straw mat. During continuous overcast days, increase light as much as possible on the premise that frost damage does not occur. If the bed temperature drops after the mat is uncovered, the straw mat should be uncovered, and then covered again before 3 p.m. If the bed temperature drops only slightly, it can be uncovered and covered as needed. Do not leave the mat uncovered for several days. During rain and snow, uncover and cover the straw mat as needed during pauses in the rain and snow. If light is insufficient for a long time, fluorescent lamps can be used for artificial supplemental lighting. After a long period of overcast followed by sudden clearing, uncover the mat slowly, otherwise it is easy to cause seedling scorching or even seedling collapse. If the seedlings are found to be wilting, cover them with shade immediately, and wait until the watermelon seedlings recover to normal before uncovering again. Repeat this several times until they no longer wilt. Then uncover all the straw mats, and afterward enter normal management.
7-10 days before planting, increase ventilation and lower the temperature to harden the seedlings
During the day, 15-20 degrees; within the limit that the watermelon seedlings are not damaged by freezing, lower the nighttime temperature as much as possible, down to 8-10 degrees, so that the watermelon seedlings adapt to the environmental conditions after planting.