Watermelon Greenhouse Planting Technology Tutorial, Full Analysis of the Latest Methods
Watermelon is a famous summer fruit, also known as summer melon, cold melon, Qingmen Lvyu Fang, etc. It is an annual trailing vine plant of the Cucurbitaceae family, genus Citrullus. Its original species may have come from Africa, and it has long been widely cultivated in tropical to temperate regions around the world. It was first introduced to China around the Jin and Yuan dynasties, and is now commonly cultivated throughout our country. Let us take a look together at watermelon greenhouse planting technology!
Variety Selection
There are many cultivated varieties of watermelon. Watermelon varieties suitable for early spring greenhouse cultivation are required to be early-maturing and high-quality, while also having characteristics such as easy fruit setting, disease resistance, high yield, and suitability for market demand. Based on summaries from recent years, the main varieties suitable for greenhouse cultivation include Jinmei Daguo, Zhizun, Lidu, etc.
Rootstock Selection
Watermelon rootstock is required not only to have good and stable compatibility with watermelon grafting, but also to have good disease resistance and no adverse effects on watermelon quality. According to observations in recent years, gourd rootstock performs poorly against watermelon acute wilt and can easily cause incalculable losses, while pumpkin rootstock performs relatively better. Therefore, at present, basically all watermelon rootstock uses pumpkin rootstock. Currently, the better rootstocks include Zhuangsi, Pumpkin No. 2, Pumpkin Changbai Daban, etc.
Seed Treatment
Rootstock seeds and watermelon seeds are treated in the same way. Soak the seeds in warm water at 25-30°C for 48 hours. After soaking, wash the seeds several times in clean water and rub them repeatedly to wash away harmful substances on the seed surface. Then wrap them well in fine cloth and place them in a constant-temperature cabinet at 27-30°C for germination, or insert a thermometer and place them on a heated kang for germination. The germination length is best when the seeds have just sprouted white.
Sowing Technology
The sowing period for greenhouse watermelon is preferably around December 20 on the solar calendar. Place the germinated rootstock seeds in the middle with the embryo bud facing down, then cover with floating soil (fine sandy loam) and cover with 1.5-2 cm of soil. Under normal circumstances, about 5 days after sowing the rootstock seeds, watermelon seeds can be germinated. Watermelon seeds can be germinated in a sand box.
Grafting Technology
1. Grafting time: Grafting can be carried out after the cotyledons of the rootstock seeds have flattened out, which is also the best time for grafting.
2. Grafting method: Use the top insertion method. During grafting, remove the growing point of the rootstock, use a bamboo skewer at the cut of the rootstock, insert obliquely downward at 45 degrees along the direction of the cotyledon line into the hypocotyl below the cotyledons, to a depth of 0.5-1 cm, with the top of the bamboo skewer reaching the cortex on the other side of the hypocotyl below the cotyledons. Then immediately take out the scion seedling, place it on the index finger, and cut it at 45° with a blade. After trimming the scion seedling, immediately pull out the bamboo skewer and insert the scion seedling along the direction of the bamboo skewer hole.
3. Grafting management: Keep the temperature at 25°C, and keep the low temperature at 24°C. For the first three days after grafting, keep it closed without ventilation and without air exchange, so that the air humidity reaches saturation. One week before planting, lower the ground temperature to 15-13°C, and lower the air temperature to 23°C during the day and 13°C at night, with the nighttime minimum not lower than 10°C, in order to harden the seedlings and bring the seedlings close to the environmental temperature after planting.