Suitable conditions for growth of tea trees

The shape of heat is generally expressed by temperature, while the main factors affecting the growth of tea trees are air temperature and soil temperature. The biological lowest temperature of tea plant is generally about 10 ℃ (growth threshold temperature). The early bud species are less than 10 ℃, while the late bud species are higher than 10 ℃. The optimum temperature for the growth of tea trees refers to the most vigorous and active temperature of tea trees, which varies with different varieties and producing areas, mostly 20 ℃ ~ 30 ℃. The temperature difference and the temperature difference between day and night directly affect the accumulation of photosynthetic matter. High temperature during the day, more light and matter synthesis, low temperature at night, less consumption of respiratory products, so the temperature difference between day and night is large, which is conducive to the formation of biological yield. From the perspective of different seasons, the effect of air temperature on shoot growth in spring was significantly greater than that in summer and autumn. The annual growth of tea plant is suitable for accumulated temperature, and the active accumulated temperature of no less than 10 ℃ should be about 5000 ℃. After December, when the average temperature is lower than 10 ℃, the tea trees will go into hibernation, when the temperature drops to 1 ℃ ~ 2 ℃, the germinated tea buds will scorch, and when the temperature drops to-2 ℃, most of the camellias will fall off and die. Generally, shrub tea has strong low temperature tolerance (about-12 ℃), small tree tea takes the second place (- 8 ℃), and tree tea has the weakest (Yunnan big leaf species is about-5 ℃). The lowest critical temperature of tea tree varies with variety, tree age, tree potential and weather conditions when low temperature occurs. The highest critical temperature for tea plant tolerance is 45 ℃. Under natural conditions, when the daily average temperature is more than 30 ℃, the tea shoot grows slowly, and when 35 ℃ lasts for several days, the new shoot will wither and lose leaves. The varieties with southern type genes tend to have strong high temperature tolerance.

Soil temperature affected the growth of tea root system, and the optimum temperature for root growth was 25 ℃ ~ 30 ℃. When soil temperature was 10 ℃, it had little effect on root growth, but there was a very significant positive correlation between soil temperature and shoot growth. 14 ℃ ~ 20 ℃ soil temperature was the most suitable for new shoot growth, and the effect of soil temperature on new shoot and root growth was related to soil texture, water condition and tea varieties.