The Latest Key Points to Note for Rapid Apple Seedling Propagation
Apple is one of the most common fruits in daily life, and it is also one of the fruit trees with the largest planting area in our country. In cultivation, rapid seedling propagation techniques can produce robust young seedlings extremely quickly, saving a great deal of time for production. However, there are several points to note with rapid seedling propagation. Let's take a look together below.
1. Choose fast-growing rootstock
Among apple grafting rootstocks, crabapple (Malus prunifolia) and Midget crabapple (Malus micromalus) are relatively cold-resistant, drought-resistant, waterlogging-tolerant and salt-alkali-tolerant, and they have strong grafting compatibility with apple, well-developed root systems and fast seedling growth. Generally, they can grow to grafting thickness by the summer of the same year. Choosing fast-growing rootstock is the foundation of rapid seedling propagation.
2. Grasp the seedling propagation time
For apple seedling propagation, autumn sowing is preferable. The climate at this time is mild, which is favorable for seed germination. After sowing, mulch film should be applied immediately. For spring sowing, sowing should be done early to avoid the seedlings encountering high-temperature weather during growth, which is unfavorable for seedling growth. At the same time, cold protection and moisture retention measures should be taken. Common protection measures include windbreak barriers against cold wind, sun-facing seedbeds, hotbeds, and plastic film mulching. Concentrated seedling propagation is done by covering the seedbed with plastic film and greenhouse film. Then the seedlings are transplanted to an open-field grafting nursery. This method can advance the sowing period, but transplanting must wait until after the late frost.
3. Pinching and grafting
When the rootstock seedlings grow to 30 cm, pinch off the growing tip to promote thick, sturdy stems. When the stem diameter reaches 0.5-0.6 cm, grafting can be carried out, and grafting must be completed before the end of June. Grafting generally adopts the high-position bud grafting method. After the seedling survives, do not cut it immediately; instead, at 1-2 cm above the grafted bud, bend and damage the rootstock without breaking it, to promote the grafted bud to sprout. Wait until the grafted bud grows 5-6 true leaves before cutting the rootstock.
4. Strengthen fertilizer and water management
Choose loose, fertile plots as the nursery, and increase the amount of base fertilizer applied. From seedling establishment to before grafting, apply 10-15 kg of urea per mu along with watering. After successful grafting, apply 8-10 kg of urea per mu; in August-September, apply 8-15 kg of compound fertilizer per mu each time, and at the same time spray foliar fertilizer once every half month, spraying a 300-fold urea solution in the early stage and a 300-fold monopotassium phosphate solution in the later stage.
The above are the key points to note for rapid apple seedling propagation. We hope it can help you. If you want to learn more related knowledge, please stay tuned to us.