Technical measures for Prevention of Heat damage in Tea trees

The heat damage of tea tree refers to the meteorological disaster which results in the reduction of tea production, the hindrance of tea tree growth or the death of tea plant under the condition of long-term high temperature and dry climate. Tea is native to the subtropics and belongs to perennial evergreen plants. It has the habit of being warm, humid, shady and afraid of drought. When the persistent high temperature and excessive drought, the red sun is hot, the rainfall is less, and the air relative humidity is less than 50%, the transpiration of the leaves is enhanced, and the water absorbed by the roots can not make up for the consumption of the aboveground part, thus withering and falling leaves of the tea tree, and even death. In order to prevent the heat damage of tea trees, in addition to selecting heat-resistant tea varieties, suitable three-dimensional growth conditions and paying close attention to the local weather forecast, the main measures are to do a good job in summer management of tea gardens and improve the ability of heat resistance and drought resistance of tea trees.

First, the tea garden is covered. The covering of tea garden is mostly in the form of grass laying between rows. Grass laying between rows is economical and affordable, and all kinds of weeds, leaves, straw and so on can be used. According to the Fujian Tea Research Institute, the annual soil moisture content of the 0-50 cm soil layer in the grass-paving tea garden is more than 1% higher than that of the unpaved grass, and 4% during the summer drought. Grass laying in the tea garden should be carried out before the disaster occurs, otherwise it will affect the effect. Generally, the effect of laying grass is better at the end of June and the beginning of July. The suitable amount of grass laying is 1500 kg / mu and the thickness is about 10 cm.

Second, tea garden irrigation. The tea garden with low groundwater level and dry soil can be irrigated at the right time. It is reported that the irrigation of tea garden in dry season can reduce the soil surface temperature by 6-7 ℃, thus alleviating the situation of baking and baking on tea trees in summer. Summer irrigation is best carried out at night (usually when the temperature drops below 30 ℃) and finished before 8 o'clock in the morning.

Third, tea garden intercropping. The effect of tea garden intercropping is ideal for young tea garden. Intercropping black cowpea, mung bean and peanut in 1-2-year-old tea garden can not only replace the grass laying of tea garden, increase soil organic matter, improve soil structure, but also improve the microclimate of tea garden in summer and prevent direct sunlight. Reduce tea transpiration and soil water evaporation. Thus play the role of heat prevention, drought resistance and seedling protection. According to the investigation, the heat damage rate of summer tea trees in young tea gardens intercropped with green manure is 20-40% lower than that in non-intercropping tea plantations.

Fourth, fattening management. As far as tea garden management is concerned, there are many measures to improve the ability of tea trees to prevent heat and drought. In addition to the above measures, fertilizer cultivation is an important link. If the tea tree is nutritious, it will grow vigorously, and its stress resistance will be enhanced accordingly. From the investigation of heat damage of tea trees, it is found that the tea gardens with severe damage are often those with no basal fertilizer or insufficient fertilization in the winter of the previous year. Therefore, sufficient basic fertilizer should be applied to the tea garden in winter and topdressing should be applied after spring tea to improve the heat resistance of tea trees.

Fifth, establish a tea forest (fruit) compound ecological tea garden. From the ecological point of view, the tea forest (fruit) compound ecological tea garden can effectively improve the microclimate of the tea garden and create a good compound ecological environment for the growth of tea trees, which is beneficial to the heat resistance and drought resistance of tea trees and improve the quality of tea.