What important links must be paid attention to in the cultivation of ginkgo seedlings?

Nursery selection, soil preparation, seed selection and storage, sowing methods, seedling management and other important links must be paid attention to in seedling cultivation. A problem in one link may lead to seedling failure. Selection of nursery land: Ginkgo nursery land should be flat or gentle slope land, shady or semi-shady slope land with loose soil and good drainage, and sparse forest or orchard seedling raising effect is often very good. Ginkgo biloba seedlings are most afraid of stagnant water. Once they encounter stagnant water, the roots will rot, leading to the death of seedlings in pieces. Therefore, plots with high groundwater level and easy to accumulate water in rainy season are not suitable for seedling raising. Ginkgo seedlings can't be continuously planted. The previous crops were Chinese cabbage, potatoes and tomatoes, and it is not suitable for raising ginkgo seedlings. In places with direct sunlight and prone to drought, seedlings must have irrigation water sources. Nursery should be prepared in late autumn or early winter. For example, in early spring, 90% crystal trichlorfon powder or 3% carbofuran powder toxic soil is first sprinkled, turned into the soil, and raked to kill germs and pests in the soil. Border width 1.0 ~ 1.2m, height 30cm. First, turn the border soil to both sides, cover the border surface with decomposed manure, then cover the turned soil with manure, rake it flat, and water it for one day 10 ~ 15 days before seedling raising.

Seeds for seed selection and storage and seedling raising should be collected from mature trees free of pests and diseases, and there should not be too many seeds in that year, otherwise the embryo will be stunted. The seeds used to cultivate "four-sided" green seedlings and seedlings of timber forests and leaf forests should be above medium size, with 450-500 seeds per kilogram. If you cultivate rootstocks, try to use well-developed small seeds, more than 600 per kilogram, which can save the cost of seedling raising. Seeds for seedling raising should be harvested in the middle and late stage of complete maturity 10, and the embryo is still in the round embryo stage at the time of harvesting. It is difficult to see embryos with naked eyes when dissecting seeds. Therefore, after the seeds are harvested and peeled, they should be dried in the shade 1 ~ 2 days, and they should be dug on the sunny and dry gentle slope outdoors for storage. The depth of the cave is about 60 cm, and the size depends on the number of seeds. Fill the bottom of the cave with sand with a thickness of 10 ~ 15 cm, and then lay the seeds on the sand in layers for storage. The water content of sand is caked by hand and scattered by hand, and the water content is about 7%. The ratio of seeds to sand is about 1∶8, layered to 20 cm above the ground, covered with fine sand to form steamed bread, covered with straw, and ditched around the hole for drainage. This method of storage, moisture preservation and temperature change is beneficial to the physiological activities of seeds and the development of embryos. Also, seeds are stored on the edge of the nursery with sand layers, usually 3-3 layers, covered with 20 cm of sand and covered with straw. The seeds dried in the shade are directly placed in ventilated sacks, placed in a cool room or aired, and sown in the next spring, and the effect is also very good. In seed storage, it is absolutely necessary to prevent water from accumulating in the hole or the seeds from being buried too deep, and the seeds will rot due to poor ventilation. No matter how the seeds are stored, the seeds will be clearly visible after 1 month. At this time, it is necessary to check the development of seed embryos. If there are too many seeds without embryos, they cannot be used as seeds. Wash it in the shade immediately, and then put it aside to eat. Therefore, seeds purchased from other places must be collected 1 month, so as to check the development of embryos. The embryo-free rate of ginkgo seeds is generally 15% ~ 25%. If there are too many seeds, or if there are long-term droughts or other natural disasters during the seed development, the embryo-free rate can reach more than 60%, so it is necessary to check the embryo development of seedlings. Seeds stored in sand usually germinate from February to March in the following spring. When more than 50% of the seeds are found to be cracked, sow immediately, and don't wait for the germ to elongate, so as not to damage the germ. Dry seeds should be sown as early as possible in order to emerge early. Sowing, drilling, spacing of 20-30 cm, width 10 cm, depth of 2-3 cm, and plant spacing of 5-6 cm. After the strip is opened, flatten the soil at the bottom of the strip. After the seeds are placed, cover them with fine sand or burnt mud ash for 2 ~ 3 cm (2 cm for small seeds), and then cover them with a thin layer of straw. Sowing in early spring and mulching with plastic film can prevent rodent damage and early emergence.