What are the precautions for green seedlings to leave the nursery?

Seedlings leaving the nursery is the last step of cultivating seedlings, and the quality of seedlings directly affects the quality of seedlings and the survival rate of planting. When raising seedlings, we should pay attention to the following two issues: the standard and time of leaving the nursery. Only when the seedlings reach the conditions of strong branches on the ground, good maturity, full buds, sound roots, many fibrous roots and no pests and diseases can they leave the nursery. Seedlings usually emerge during the dormancy period of seedlings. Deciduous tree species can be carried out from the beginning of defoliation in autumn to the beginning of sap flow in the following spring. Besides the above time, evergreen trees can germinate in rainy season. Raise seedlings in early spring, and raise them well before they start to sprout. For example, the seedling raising time of Cinnamomum camphora should be in mid-June 165438+ March of the following year, when the new buds of Cinnamomum camphora are obviously prominent until the new buds appear light green. If the seedlings are regenerated after budding, the survival rate of the seedlings will be greatly reduced. Sowing in autumn should be carried out after the growth of seedlings on the ground stops, when the roots are growing. If the seedlings can be planted in time, they can start to grow earlier in the next spring. In addition, the heel in the program can be reduced by sprouting in spring. The first way out of the nursery is that the seedling depth should be based on the root distribution law of tree species, and it should be deep rather than shallow, because too shallow will easily damage the root system. If the seedlings have few roots, it will lead to low survival rate or weak growth after planting, so it is necessary to minimize root damage. Dig far away. If the fruit trees begin to sprout, dig 20 cm deep from the side of the seedlings and keep the length of the main lateral roots of the seedlings at least 20 cm. Be careful not to damage the cortex and bud eyes of seedlings. For long taproots and lateral roots, they can be cut off because they are inconvenient to dig, and it is forbidden to close seedlings by hand. Second, water the nursery before raising seedlings. Because of the drought in winter and spring, the soil in the nursery is easy to harden and it is difficult to raise seedlings. It is best to water the seedlings 4-5 days before emergence, so that the seedlings can absorb enough fertilizer and water and have rich nutrient reserves, ensure the integrity of the root system of the seedlings and enhance the drought resistance of the seedlings. The third is to bring soil balls when digging seedlings. When raising seedlings, soil balls are brought to the roots, and the diameter of the soil balls can be 6 ~ 12 times of the diameter of the roots, so as to prevent the roots from losing water when exposed to air. Precious tree species or trees can also be wrapped with straw ropes to prevent soil balls from scattering. At the same time, after planting, they are closely connected with the soil, and the roots can recover and absorb quickly, which is conducive to improving the survival rate. From buying and selling seedlings