Cultivating healthy seedlings is essential for achieving successful outcomes after the park's establishment. In the nursery, several key factors must be carefully managed. First, selecting and cultivating rootstocks is crucial. In Hebei and Shandong, common walnut seedlings are typically used as rootstocks. However, many wild walnut varieties can also be utilized depending on the region. Wild walnuts are a natural resource that can be tapped for propagation. When collecting seeds, timing is important—walnuts harvested in early September have a germination rate of less than 50%, while those collected from late September to early October have a germination rate over 90%. After harvesting, remove the green husks, and if they are dried, treat them with sand before the soil freezes. Use salt water to select plump seeds, then layer them in wet sand, placing one layer of sand followed by a layer of walnuts, repeating this until the pile reaches 20 cm. Cover the top with wet sand and mound soil around it. Place a bundle of straw in the center to allow air circulation. Check the seeds 1–2 times before spring planting. If the seeds are dry, soak them in cold water for 5–7 days, changing the water daily, or soak them in 10% lime water for 10–13 days, stirring 1–2 times a day. After soaking, expose them for a few hours and then place them in a warm bed or fire pit at 20–25°C. Germination usually takes about a week. Once the soil thaws, you can begin sowing. Apply 5,000 kg of organic fertilizer per acre, level the ground, and create 1-meter-wide beds. Plant seeds with 30 cm between rows and 15–20 cm between plants, digging trenches 10 cm deep and covering them with 5–7 cm of soil. When planting, ensure the seed’s suture is perpendicular to the ground, and position the tip properly. The seeding rate is approximately 110–130 kg per acre, resulting in 7,000–8,000 seedlings. After emergence, focus on proper fertilization, watering, weeding, and pest control during the seedling stage. In drier areas, live gardens are often established by sowing 2–3 seeds per hole, allowing the rootstock to grow for 1–2 years before grafting. Dig pits 25–30 cm deep, loosen the soil, add organic fertilizer, and plant the seeds. Cover the seeds with 12 cm of soil and leave a small pit 14–16 cm deep above them to help retain moisture and promote seedling growth. Second, grafting is an important technique. Common methods include branch grafting and bud grafting. (1) Branch grafting is best done from the rootstock’s growing period to the early flowering stage, typically mid-April in North China. Use branches from the middle or lower part of a vigorous, well-developed branch or a long fruit branch. Cut the scion into bud branches, and dip the cut ends in melted wax at 95–100°C. Grafting techniques such as cleft grafting and bark grafting can be used. It is essential to tightly wrap the graft interface. To reduce the impact of wound exudate on graft survival, the rootstock should be watered before grafting. Make 3–5 diagonal cuts around the base of the rootstock, cutting into the xylem to allow the wound fluid to drain. The number of cuts depends on the rootstock thickness and the amount of exudate. (2) Bud grafting is commonly performed in North China from mid-July to mid-August. The best time is right after picking, and leaves should be removed immediately. Common methods include T-budding and square budding. T-budding has proven effective in recent years, as it allows the micro-injury flow to cross the transverse cut, reducing damage to the bud and significantly improving survival rates. (3) After grafting, it is important to remove the binding material promptly once the grafts survive. When the scion begins to sprout, apply 10–15 kg of urine fertilizer per acre. Fertilization should always be combined with irrigation. When seedlings reach 20 cm in height, support them to prevent wind damage. Additionally, monitor for pests and diseases to ensure healthy growth.

API

what is API?

High-purity plant monomer refers to one or more single chemical components with specific biological activity or pharmacological effects extracted from plants, and its purity is usually high, meaning that the content of the component in the extract reaches a certain percentage, and the content of other impurities or irrelevant components is low.

These plant monomers are usually secondary metabolites of plants, such as flavonoids (flavonoids), alkaloids (alkaloids), terpenoids (terpenoids), phenolics (phenolics), etc., which play a variety of physiological functions in plants such as defense, signal transduction, and antioxidant. Due to their pharmacological activity, high-purity plant monomers are often used in pharmaceuticals, health products, cosmetics and other biotechnology products.

For example, Naringenin is a high-purity plant monomer extracted from citrus plants with antioxidant and anti-inflammatory activities; Corosolic acid is a high-purity active monomer extracted from loquat leaves, which is considered to be effective in treating type 2 diabetes and obesity.

Extraction and preparation of high-purity plant monomers usually require a complex separation and purification process, including extraction, column chromatography, crystallization, recrystallization and other steps to ensure the purity and activity of the final product. These processes may be required by specialized biotechnology companies.

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