Key points of tea cultivation: selecting improved varieties and reasonable close planting

1. Selecting improved varieties Seeds (seedlings) are the basic means of production in tea cultivation, and any cultivation method is built on the improved varieties of a given period. Since the 1980s, tea cultivation has entirely adopted the close-planted, dwarfed, no-tillage method. Because individual space is reduced and population density increased, it is all the more necessary to match this with suitable improved varieties in order to achieve the desired results. For example, Fuding Dabaicha, Qianmei 101, Qianmei 303 and others are all fine tea varieties suitable for close planting.

2. Collection and handling of tea seeds The best time for seed collection is from Cold Dew to the Beginning of Winter. If seeds are collected too early, the seed embryo is immature and material accumulation is insufficient, affecting emergence and seedling growth. If collected too late, the tea seeds fall to the ground, which not only wastes a great deal but also misses the suitable sowing period. After harvesting, the fruit shells of the tea fruits should be removed promptly, and the tea seeds spread out to dry in a cool, ventilated place, with a spreading thickness generally not exceeding 10 cm, and turned frequently so that the seeds are evenly aerated and uniformly dry and moist, after which they are sown immediately. To speed up seed germination, eliminate accompanying pathogens and promote uniform, vigorous seedlings, the tea seeds must also be disinfected before sowing. First remove seeds that are damaged by pests or disease, moldy, split in the seed coat, shriveled or empty-shelled, then screen them to separate large and small seeds for separate sowing, and after emergence strengthen the care of seedlings from small seeds to make up for their inherent deficiencies. For winter sowing, tea seeds may be sown directly without soaking to swell; before sowing, disinfect the seeds with 1%-2% formalin solution or 1% copper sulfate solution, soak for 1-2 hours, then immediately remove and rinse with clean water before sowing. For spring sowing, because the seeds have been stored for a longer time and their water content has decreased, they must be soaked in clean water for 3-4 days before sowing until they absorb water and swell to the point where part of the seed shells split, and only then are they taken out for sowing.

3. Reasonable close planting So-called reasonable close planting means selecting fine varieties, adopting a suitable planting density and planting method, and applying comprehensive agricultural techniques to establish a dynamic population structure that is reasonably balanced at every stage from seedling to maturity, so as to make full use of soil fertility and light energy and obtain the greatest economic benefit per unit area. For the planting specification, within a row width range of 120-150 cm, 2-3 small rows may be arranged, with a row-to-clump spacing of 30-40 cm x 23 cm, sowing 7-10 seeds per hole, and a seeding rate of 40-50 kg per 667 sq m. When planting, attention should be paid to mastering the following technical points:

(1) Deep plowing and sufficient pre-planting base fertilizer. For tea gardens that already meet the deep-plowing requirement when the land was opened up, sowing can be done as long as sufficient base fertilizer is applied. If the land-clearing depth is insufficient, supplementary plowing should be carried out before planting, followed by fertilizing and planting. If the base fertilizer per 667 sq m is barnyard manure, compost or decomposed green manure, 2000-4000 kg is needed, plus 100 kg superphosphate, and the seedlings can emerge 10-15 days earlier than with spring sowing, with a higher emergence rate as well. Where conditions permit, every effort should be made to sow promptly in November-December of the same year. In high, cold mountain areas with heavy winter snow and ice, or where externally sourced seeds have missed the suitable sowing period, spring sowing may also be carried out, but time must be grasped firmly and the entire sowing work completed before the end of March.

(2) Hole sowing with shallow soil covering. In newly planted tea gardens, multi-seed hole sowing should be practiced to strengthen the population advantage and stress resistance of the seedlings. The number of seeds sown per hole should be determined according to seed quality: generally 5-10 seeds for good-quality seeds, while 10-15 seeds are needed for poorer-quality seeds, and thinning and final spacing are carried out after emergence. After the tea seeds are sown, the soil covering should be shallow rather than deep, generally not exceeding 7 cm. If the soil covering is too deep, the seedlings have difficulty emerging, and a large amount of nutrients is consumed in growth within the soil; after emergence the seedlings are often weak and cannot withstand the high-temperature environment under the scorching sun, and are very easily scalded. With poor-quality seeds, the nutrients of the mother body may even be exhausted before the seedlings emerge, resulting in missing plants. If the soil covering is too shallow, it cannot withstand rain erosion, and the tea seeds exposed on the ground surface cannot germinate and emerge either. The soil covering the tea seeds should be loose, soft and finely broken, not cloddy or lumpy. Some protective material, such as sawdust, forest leaf mold or rice husks, may also be spread on the soil surface, which can both keep the soil loose and moist and prevent erosion by water, and is very beneficial for tea seed germination and emergence.

(3) Transplanting tea seedlings. Transplanting tea seedlings is highly technical and must be treated seriously, so that each patch planted survives and each patch quickly reaches high yield. The main keys are as follows: 1) Timely transplanting. Grasp the suitable period for transplanting. Transplanting tea seedlings should be carried out when aboveground growth has stopped and the underground root system has begun to grow, because transplanting at this period favors the rapid restoration and development of the root system. Root growth activity is more vigorous and lasts longer in late autumn and early spring, so transplanting is generally suitable in September-November and in February-March of spring. 2) Lifting seedlings. When lifting seedlings, carry as much soil as possible and injure the roots as little as possible. The root system of tea seedlings is closely interwoven with the soil; if no soil is carried or only a little soil is carried, a large number of absorbing roots will be damaged, affecting survival and growth after planting. In order to carry more soil when the tea seedlings leave the nursery, the nursery should be given one thorough watering the day before lifting the seedlings, so that the tea roots and soil, and soil and soil, bind together easily and more soil can be carried; if the nursery is sandy soil, even greater care should be taken. At the same time as lifting the seedlings, selection of the stock should be carried out, removing diseased plants, weak plants, impure plants of mixed varieties, and seedlings that are relatively severely damaged. Where long-distance transport makes it inconvenient to carry soil, or sandy land makes it difficult to carry soil, after taking out the seedlings the roots should be dipped in yellow mud slurry, and water management strengthened during transport and after planting. 3) Doing transplanting well. Transplanting seedlings is best done on cloudy days or after rain. Before setting out the tea seedlings, planting trenches should be dug and base fertilizer applied well. When planting, first place the seedlings according to the previously calculated density and row-to-plant spacing, then plant them. The planting method is to hold the seedling with one hand so that the tea roots spread out evenly in their original natural form, while the other hand slowly fills in fine soil, pressing lightly while filling so that the tea roots combine with the soil. After the trench is filled with soil, tread it firm with the foot, then water in the settling water, and after the water has soaked through the soil, cover the surface with a layer of loose soil. The planting depth should preferably exceed the original root crown by 2-3 cm. After transplanting is completed, pruning should be carried out in good time, with the amount pruned depending on the degree of root damage: where root damage is slight, the plants may be pruned to a height of 20-25 cm; where root damage is greater, 15-20 cm is preferable, so as to balance aboveground and underground income and expenditure, enable the seedlings to recover from root wounds quickly and develop and grow normally on schedule. If continuous sunny days occur before aboveground growth is normal, the seedlings should be shaded and watered so that the soil remains moist at all times, and only then can the tea seedlings survive.