Detailed Explanation of the Short-Cutting Cutting Propagation Technique for Tea Plants in Nutrient Bags

The short-cutting cutting propagation technique for tea plants in nutrient bags is the process of using nutrient bags to directly insert short cuttings and cultivate plants. This asexual propagation method can effectively maintain the characteristics of the mother tea plant, produce offspring with uniform traits, help cultivate strong seedlings, avoid damaging the root system during transplanting, and effectively increase the survival rate. However, the seedling propagation technique is demanding, and the process is relatively complicated; if not mastered well, it can easily lead to failure. The following technical points should be noted in seedling propagation:

1. Build a shade shed

The shade shed has the functions of sun protection, wind protection, and frost protection. It is an important part of the success or failure of nutrient bag seedling propagation. The shade shed is generally built as a flat-topped high shed, with a height of 2-2.5 m. Multiple bamboo poles or wooden stakes are used as top supports, and the top and surroundings are pulled into a net shape with No. 8 iron wire, then covered with shade netting of 40%-60% shading degree. The surroundings should be covered tightly and pulled tight, leaving only one door for personnel to enter and exit and to operate inside. The size of the shed is determined according to the scale of seedling propagation.

2. Preparation of nutrient bags, nutrient soil, and sterile soil

1. Preparation of nutrient bags. Select plastic bags 10-15 cm long and 8-10 cm wide as nutrient bags. Punch 2-4 small holes of 0.5 cm around them to allow air and water permeability.

2. Preparation of nutrient soil. It is made by mixing red-yellow soil topsoil or mountain base soil with fertilizer. For every 100 kg of soil, mix 30 kg of farmyard manure, add 0.2 kg of ammonium sulfate and 0.3 kg of superphosphate, or use 100 kg of soil, mix 30 kg of farmyard manure, and add 5 kg of compound fertilizer. When preparing nutrient soil, both soil and fertilizer must be fully crushed, sieved, and mixed evenly.

3. Preparation of sterile soil. Take uncontaminated red or yellow subsoil (also called new soil or raw soil) that has not been in contact with the outside, crush it, and sieve it. This type of soil has few microorganisms, which is beneficial for the healing and rooting of cutting wounds, while also reducing weed growth.

3. Bag filling and bed building

1. Bag filling. When filling bags, first fill 2/3 with nutrient soil, shake tightly and compact, then fill 1/3 with sterile soil and compact again.

2. Bed building. Before building beds, first use herbicide to weed and seal the seedling plot. Then, arrange the filled nutrient bags closely into beds, with a bed width of 1-1.2 m, and the length determined by the plot. The distance between beds is 30-40 cm, used as walkways. The surroundings of the beds are enclosed and fixed with bamboo strips, and soil is banked up to the same height as the nutrient bags. The gaps between bags are filled with soil, which helps keep the nutrient bags stable and preserve water and prevent drought.

4. Selection of branches and cutting of short cuttings

1. Selection of branches. Select branches that are free from disease and insect damage, grow robustly, have intact leaves, plump axillary buds, and are semi-lignified reddish-brown branches grown in the previous season. Branches that are too old or too tender are not conducive to rooting.

2. Cutting of short cuttings. Cut cuttings 3-4 cm long, retaining one internode, one axillary bud, and one leaf, and cut off 1/3-1/2 of the leaf. The upper and lower cut ends of the cutting should be slanted and parallel, consistent with the direction of leaf attachment, and the upper cut should be 3-4 mm from the petiole. When cutting cuttings, if the branch internodes are too short but the buds and leaves are still good, two nodes can be cut as one cutting, and the lower leaf can be removed.

5. Cutting technique

1. Cutting time. In most areas, it is carried out from March to November. According to the climatic conditions and farming arrangements of Lianghe County, the cutting time is mostly chosen from August to November.

2. Treatment of short cuttings. Soak the base of the cut short cuttings in 30-80 ppm naphthalene acetic acid or a 1:1000 rooting powder solution for 30 minutes. After treatment, the wounds can heal earlier, rooting can occur earlier, and the survival rate can be increased.

3. Cutting. Before cutting, water the soil in the nutrient bags until wet and thoroughly soaked, watering at least twice, so that after the cuttings are inserted into the soil, they are not damaged and the bark does not peel off. Wait until the soil does not stick to the hand when pressed, then proceed with cutting. When cutting, hold the upper end of the short cutting between the thumb and index finger, insert it gently into the soil at a certain slant angle, and use the two fingers to slightly press and compact the soil around the cutting. The leaf and petiole should be exposed above the ground, and the leaf should not be pressed tightly against the ground, so as to avoid adhering to mud and falling off, which would affect survival. To ensure the survival rate, 1-2 cuttings can be inserted into each nutrient bag. After cutting, water once more to ensure the stability of the cuttings and close contact between the cuttings and the soil.

6. Build small arched sheds

After cutting is completed, each bed should be covered with a small plastic arched shed. The method is to use bamboo strips 3-4 cm wide, 1 cm thick, and 130-150 cm long, insert the two ends into the two sides of the bed respectively to form an arch, insert one every 1.5-2 m, and insert one each at the head and tail of the bed, then cover with plastic film and press the surroundings tightly and compactly with soil so that no air leaks. In this way, it can both preserve water and keep warm, and the average temperature can be maintained between 25°C and 28°C, which is beneficial for speeding up the healing and rooting of cuttings, rapid growth, and earlier release from the nursery. The small arched shed is also protected by shade netting, which can also protect against sun, wind, and frost, forming double protection above and below.

7. Management after seedling propagation

Whether tea plant cutting propagation in nutrient bags can survive and grow robustly depends greatly on management after seedling propagation. The following points should be carried out well:

1. Observe frequently. If soil moisture is found to be insufficient, uncover the film in time to water or irrigate, then cover it again.

2. Observe the temperature inside the arched shed. If it is higher than 30°C, uncover the film at both ends of the small arched shed in time to cool it down so as to avoid burning the seedlings.

3. Remove weeds in time and strengthen the prevention and control of diseases and insect pests.

4. Reasonable fertilization. Three months after cutting, fertilization can be carried out together with weeding and disease and insect pest control, or separately. Spray an appropriate compound fertilizer aqueous solution with a watering can, or apply an appropriate urea combined with Genbao dissolved into a solution, spraying once every half month or one month, and fertilization can be carried out multiple times.