The winter and spring season is when the weather is cold. At this time, the melon vegetable nursery needs to be carried out in a greenhouse or a small arch. If we want to breed high quality and strong seedlings, we must strengthen the management of the greenhouses, scientifically adjust the temperature, humidity, light and other factors in the greenhouse to promote the emergence of seedlings and seedlings as soon as possible. Now we will introduce the following points:
1 Temperature Management
After the melon vegetables are sown, the temperature of the seedbed is the main factor affecting the seedling emergence. The soil temperature is too low, and rotten seeds are prone to occur. Therefore, in the cold season sowing, it is best to use heating hotbeds, electric hotbeds, or temporary warming and other measures (such as adding plastic film, small arch, night cover insulation material, greenhouse heating, etc.), so that the temperature, ground temperature to maintain In the optimum temperature range of 25-30 °C, the minimum night temperature of 15-18 °C or more, the night temperature of 18-20 °C, prompting the rapid emergence, Miao Qi Miao. This period is mainly to promote the emergence of seedlings, management is based on the principle of insulation, warming, generally do not conduct ventilation. Under these conditions, most of them can emerge in 3-5 days.
Hypocotyls are very sensitive to temperature and humidity when the seedlings are newly emerged. Under high temperature and high humidity, the hypocotyls will rapidly elongate to form leggy seedlings. The goal of management after emergence of seedlings is to promote the growth of seedling hypocotyls and the rapid development of roots. When the seedlings are out of alignment (the cotyledon tops out of the soil surface), the ventilation and cooling will be timely, and the humidity shall be maintained at about 25°C during the day and 15°C at night. After the first true leaf is unfolded, the night temperature can be appropriately reduced by 1-2°C to form a large temperature difference between day and night, promoting the growth of thick seedlings and female flowers, and preventing the hypocotyls from being excessively elongated. In case of rainy weather, the temperature should be properly reduced.
After cotyledon flattening, management aims to promote true leaf growth, flower bud differentiation and cultivating strong seedlings. The temperature control is mainly controlled by controlling the timing of the air release and the amount of air discharge, and the time of uncovering the heat-insulating material. It is necessary to gradually increase the amount of air release and the time of air release as the temperature rises, and the amount and position of the air release should be as uniform as possible in the seedling bed so that the growth of seedlings is consistent. The spread technology of the glutinous rice vinegar vegetable intercropping technology is firstly middle or top wind, and then it transitions to both sides or bottom. According to the changes in the weather and seedbed temperature changes to control the amount of air release and ventilation site. About 10 days before planting, the seedlings enter the hardening period.
2 Water Management
When raising seedlings in winter or early spring, watering too much or too large in the early stage can make the temperature of the seedbed fall, which is not conducive to the growth of seedlings. If the water is watered at a high temperature, it can easily cause leggy seedlings to grow. Therefore, the bottom water must be poured before planting so as to meet the water requirement for the growth of seedlings and early seedlings. Minimize watering or even watering during nursery. In the early stage of nursery, it is also possible to use the method of covering the moist soil to adjust the moisture and reduce the contradiction of the ground temperature. In the middle and late period of raising seedlings, as the temperature rises, the amount of water evaporation increases. At this time, you can choose to spray with a sprayer on a sunny day with high temperature. Under normal circumstances do not sprinkle irrigation, so as not to reduce the temperature or cause seedlings leggy. The principle of watering at the seedling stage is “no cloudy days, sunny days, no afternoon pouring, and morning pouringâ€. Seedlings should be seeded with water before sub-seedling, and seedling water should be poured when sub-seedlings are planted; watering should also be carried out on the first day before cut-off seedlings.
3 Lighting Management
Adequate light during the nursery period is conducive to the cultivation of strong seedlings. Therefore, in the winter and early spring when the low-temperature and low-light season is growing seedlings, the seedlings should be allowed to receive more sunlight as much as possible. In the nursery of protected land, the light conditions of the seedlings are not only related to the climate, but also related to the uncovering and management of the opaque cover in the protected land. These managements not only affect the light, but also affect the temperature in the protected land. In summer, vegetables should be protected as much as possible from the seedlings of the four types of pests in order to increase the temperature of the seedbed. In addition to early release of opaque cover to cover the extension of the lighting time, management should always clean the transparent cover film to increase the amount of light transmission. The film is preferably dripless. On cloudy days, opaque coverings should also be uncovered, and in the rain and snow days, opaque coverings should be uncovered for a short period of time. If we encounter successive shades, rain, and snow, the seedlings will mainly consume nutrients in their own bodies, and they will easily cause seedlings to grow yellow and grow weak, and even yellow wilt will die. Therefore, in the event of such weather, opaque coverings should be uncovered as much as possible. The seedlings receive sunlight, and even take measures to fill the light or hang a reflective film on the north side of the greenhouse.
4 cultivators and foliar fertilizers
Soil loosening can occur when soil moisture is excessive, compaction occurs, or in winter and early spring to improve the ground temperature of the nursery bed. The loose soil can be used bamboo sticks or 8 small wire to make a small lotus root, loosen or loosen the topsoil, breaking the depth of the principle of not hurting the root. The ripping soil can be carried out once after the seedlings are flushed out, when two cotyledons are flattened and when two true leaves are present.
In order to promote the normal growth of seedlings, foliar fertilization may be performed according to seedling growth conditions and fertility of the nursery bed. Generally, foliar fertilizers can be applied to two true leaves and 3-4 leaves before planting. The foliar fertilizers are mainly 0.2% urea and 0.3% potassium dihydrogen phosphate or other nutrient-type foliar fertilizers. Foliar fertilization usually takes place after 3 pm.
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