Detailed Explanation of Key Cultivation Techniques for Yongchun Finger Citron Tea

I. Planting Techniques

The construction of tea gardens should attach importance to ecological balance, without destroying natural resources, and to soil and water conservation. Proceeding from the actual local conditions of tea production, tea production bases should be built in a concentrated manner, appropriately concentrated and contiguous, so as to facilitate management, reduce costs, increase benefits, and be more conducive to centralized factory processing and improving tea quality. The construction of tea gardens should also adhere to high standards and high quality, and gradually achieve improved tea tree varieties, garden-style tea areas, water conservancy in tea gardens, and scientific cultivation.

1. Improved tea tree varieties: In light of the actual local tea types produced, ecological conditions, and so on, determine pure varieties free from contamination, and cultivate robust, high-yield, high-quality, pest- and disease-resistant Finger Citron tea seedlings.

2. Garden-style tea areas: Adjust measures to local conditions, carry out comprehensive planning, take soil and water management as the center, and implement comprehensive management of mountains, water, fields, forests, and roads, so as to achieve garden-style regionalization and specialization.

3. Water conservancy in tea gardens: When building the garden, vegetation should not be excessively damaged, and it should be conducive to conserving soil and water. Water sources should be extensively developed, and irrigation and drainage facilities for the tea garden should be well built. Water sources should meet ministerial standards, be free from contamination, and be capable of irrigation in the dry season and drainage in the flood season.

4. Scientific cultivation: Require rational close planting, heavy application of organic fertilizer (mainly farmyard manure), supplemented by chemical fertilizers (compound fertilizer, urea, etc.), correct use of plucking and pruning techniques, grasp the patterns of pest and disease occurrence, strengthen quarantine and forecasting, and adopt the plant protection policy of "prevention first, comprehensive control."

(1) Climatic conditions: The climatic requirements of Finger Citron tea trees are that they prefer warm and humid areas, with an annual average temperature above 13°C, an active accumulated temperature above 3500°C, atmospheric humidity of around 80% being best and not lower than 60%, and annual precipitation above 1000mm.

(2) Soil conditions: Finger Citron tea trees prefer acidic soil, with a pH value between 4.0 and 6.5. Within the territory of Yudou Town, the soil is red soil that is slightly acidic, which is very suitable for planting Finger Citron tea. However, when free calcium acid in the soil exceeds 1.5%, it is unfavorable to tea tree growth. In addition, attention should be paid to the effects of aeration, water storage, fertilizer retention, heat preservation, and other aspects on Finger Citron tea trees.

(3) Geographical conditions: Tea gardens should preferably be selected on hillsides or hilly areas at an altitude between 450 and 750m, with a slope below 25°, and sloping land of 10-20° is most ideal. For slope aspect, a north-facing to south-facing direction is relatively ideal, achieving comprehensive development of "afforestation on the mountain top, tea planting on the mountainside, and grain planting at the foot of the mountain."

(4) Construction of terraced tea gardens: Pay attention to the terracing principle of building along contour lines. The bed surface should be level to prevent soil and water erosion. Generally, follow the curves and terrain, and make it as straight as possible to facilitate management and lay a good foundation. It is advisable to return topsoil to the trench and use subsoil to build the embankment. Dig out the subsoil and build the embankment along the outer edge, with the embankment about 20cm high. The bed surface should slope slightly inward to help conserve water, soil, and fertilizer. The width of the bed surface depends on the slope, generally around 1.5-2.5m. Single-row or double-row planting may be adopted. A 1.5m-wide bed surface is suitable for single-row planting, and a 2m-wide bed surface is suitable for double-row planting, so as to achieve early canopy closure and early production. For plant spacing, single-row planting should adopt 0.30-0.35m, and double-row planting should adopt 0.3-0.4m plant and row spacing (planted in a staggered triangular arrangement).

(5) When building embankments with subsoil on the tea garden bed surface and returning topsoil to the trench, the trench width and depth should suit the development of the tea tree root system. It is advisable to dig a trench about 0.4m wide and about 0.5m deep, return topsoil and weeds to the trench, and apply per mu 30-40 loads of organic fertilizer (farmyard manure), 50 jin of lime powder, and 100 jin of calcium magnesium phosphate as base fertilizer, mix with soil, and then wait for planting. Choose to carry out planting during the Beginning of Spring to Rain Water solar terms. Select robust Finger Citron seedlings 15-20cm tall, free from pests and diseases, for planting. After planting, cover with rice straw and the like to help increase the survival rate.

II. Management Techniques

1. In the management of Finger Citron tea gardens, the cultivation and weeding management of young tea gardens differs from that of long-established old tea gardens. Attention should be paid not to cultivate too deeply, and the frequency should be relatively low. Cultivation and hoeing should be carried out together with the sowing of intercropped green manure and the broadcasting of fertilizer. For the depth of cultivation and hoeing, shallow cultivation should be carried out within 1-2 years, with a cultivation depth of about 8-10cm, and 2-3 cultivations and hoeings per year. As the seedlings in the tea garden grow, the cultivation and hoeing depth should continuously increase to 15-20cm. When deep cultivating, carry it out at a distance of more than 15cm from the plants, and take care to damage the roots as little as possible. At the same time, pay attention to weather changes. Cultivation and hoeing should not be carried out during long-term dry weather, so as to prevent water loss. Advocate grass cultivation and mowing grass to cover the garden, increasing humus fertilizer, so as to help loosen the soil.

2. Fertilizer and water management: Select decomposed stable manure, compost, green manure, cake fertilizer, and so on. Advocate applying organic fertilizer once a year, mainly farmyard manure, to improve the growth of young tea trees, thereby enhancing the tea trees' ability to resist pests and diseases, increasing chlorophyll, making leaves thick and plump, and improving tea quality. Applying organic fertilizer can not only provide comprehensive nutrition for tea trees, but also has a long fertilizer effect period, can increase or renew soil organic matter, promote microbial reproduction, and improve the chemical properties and biological activity of the soil. Supplement with chemical fertilizers such as compound fertilizer and urea. It is advisable to adopt the fertilization principle of thin fertilizer applied frequently, broadcasting compound fertilizer and urea once every 2 months (mixed at a ratio of 2:1). In addition, according to the characteristic that young tea trees need more phosphorus and potassium fertilizer, the ratio of the three elements is: 1:1:1 for 1-2 years old, and 2:1:1 for 3-4 years old. For the amount of fertilizer applied, 1-2 years old should receive 2-5 kg of pure nitrogen per mu, 2-3 years old should receive 5-7 kg of pure nitrogen per mu, and 3-4 years old should receive 7-10 kg of pure nitrogen per mu. The amount of fertilizer applied should also be determined according to the number of plants per mu, growth condition, soil, and fertilizer management conditions. As the tea trees grow, the amount of fertilizer applied should be appropriately increased year by year. Generally, to produce 100 kg of dry tea, 9 kg of pure nitrogen, 4 kg of phosphorus, and 2.66 kg of potassium need to be supplemented, with a nitrogen, phosphorus, and potassium ratio of 3:2:1. In short, the fertilization principle is: to achieve economical and rational fertilizer use and give full play to fertilizer efficiency, generally adopt a combination of trench application and broadcasting, and achieve scientific fertilization so as to maximize fertilizer efficiency.

3. Formative pruning: The principles of low-position pruning and dwarfing the tree canopy should be adopted to expand the plucking area and appropriately reduce height. This can reduce the number of branching levels, help the transport of water and nutrients within the tea tree, and also reduce the tree body's annual consumption of photosynthetic products, thereby increasing the economic coefficient of the tea tree. For the formative pruning of young trees, in the current year it is generally carried out in winter from September to October, cutting flat at a height of 30cm above the ground. In May of the second year, after the spring shoots harden, the formative pruning height is 40-50cm, and from September to October it is controlled within 60cm. Thereafter, depending on the growth rate of the Finger Citron tea tree, thin-branch pruning is carried out to form the canopy within 80cm, with the height generally not exceeding 1m plant height.

4. Transformation of low-yield tea gardens: For tea trees that decline before growing old, tea gardens with heavy plucking and light management, and so on, where the tree age is more than 15 years, technical measures such as deep pruning all the way to collar pruning and replanting (interplanting) should be adopted. Deep pruning generally controls the height at 50-60cm, and collar pruning controls it at 20-25cm above the ground. Because collar pruning produces shoots (new shoots) sprouting from the root crown, it has vigorous vitality, can form a neat canopy and robust tree vigor, and under strengthened fertilizer and water management can enable the tea tree to grow rapidly. It has far-reaching significance for building good Finger Citron quality, raising the grade, creating benefits, and striving for brand reputation. Practice has proved that it is feasible. For middle-aged trees around ten-plus years old, the method of deep pruning should be adopted, with the height of heavy pruning preferably 40-60cm above the ground, generally thinning and pruning away 1/3-1/2 of the tea tree, and requiring neat and level pruning. The timing of collar pruning and heavy pruning should be controlled to after the spring tea plucking.

5. Pest and disease control: The common pests and diseases in local tea gardens are tea geometrid, false-eye small green leafhopper, tea zonate leaf blight, tea tussock moth, black spiny whitefly, tea aphid, tea small leaf roller, tea leaf blight, and many other pests and diseases. Among them, the false-eye small green leafhopper, aphids, and whiteflies are the most rampant. The plant protection policy of "prevention first, comprehensive control" should be adopted. On the basis of increasing the application of farmyard manure and organic fertilizer, strengthen the robust canopy of tea trees, improve the ability to resist pests and diseases, strengthen forecasting, grasp the appropriate control period and control thresholds, and strictly implement the pesticide varieties permitted for use in pollution-free tea gardens and their safety standards, reduce pesticide residues, protect the ecological environment, and protect the number of natural enemies. Give priority to biological agents such as high-efficiency and low-toxicity ones, control pest and disease losses to the minimum extent, and follow the technical specification of giving priority to biological control and supplementing it with chemical control. The use of herbicides in tea gardens is strictly prohibited.