What technical points should be noted when introducing tea plants?

Tea plant introduction is simple and easy to achieve results. Since the 1950s, the area planted with improved varieties has been expanded. For example, the Yunnan large-leaf variety was introduced to Guangdong, Guangxi, Sichuan, Guizhou and other provinces and autonomous regions, and the area has reached more than 1 million mu. Fujian, Zhejiang and other provinces used introduced and acclimatized Yunnan large-leaf varieties as original material to breed a group of excellent high-yield new varieties. New progress has been made in introducing tea from the south to the north. The northernmost boundary of tea plant distribution in China has shifted from about 34°40'N to near 37°49'N, advancing northward by more than 350 km. Tea varieties have also been introduced successively from the former Soviet Union, Japan, India, Vietnam and other countries, such as Georgian No. 1, No. 4, No. 6 and No. 8, Yabukita, Assam and Vietnam large-leaf, etc.

There are mainly two points in introduction and acclimatization:

First, introduction from areas with similar ecological conditions is likely to succeed. Before introduction, it is first necessary to understand the degree of difference in ecological conditions such as latitude, altitude, climate and soil between the introduction area and the place of origin, among which the absolute minimum winter temperature and soil pH are the main factors. If the degree of difference is small, direct introduction can be carried out; if the degree of difference is large, the "gradual migration planting method" should be adopted.

Second, the success and difficulty of introduction and acclimatization are determined not only by the age of the plant's individual development, but also by the age of phylogenetic development. Using seed-grown seedlings as introduction material means the individual development age is young, the adaptability is strong, and the possibility of success is great; the phylogenetic age of hybrids is much younger than that of pure species, so they have a stronger ability to adapt to a new environment.

After tea was introduced from the south to the north, the tea plant changed from tall to short, the leaves changed from large to small, from thin to thick, the number of palisade tissue layers increased from one to two or three, the tea polyphenol content decreased, the water extract increased, flowering and fruiting decreased, the spring sprouting period was delayed, and the cold resistance gradually increased. After tea was moved from the north to the south, it generally showed earlier sprouting, increased flowering and fruiting, and higher tea polyphenol content. During introduction, the introduction goal should be clarified according to natural conditions and the type of tea produced; before large-scale introduction, a small-scale trial planting must first be carried out to reduce unnecessary losses; seed and seedling quarantine work should also be done well to prevent the spread of pests, diseases and weeds.