A method for evaluating the frost index of tea leaves
By establishing a tea bud dormancy model and temperature response model, combined with support vector machine interpolation, the problem of dynamic germination rate changes in tea frost assessment is solved, and accurate assessment and loss assessment of tea bud germination period is achieved.
Patent Information
- Application Number
- CN202111551317.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2021-12-17
- Publication Date
- 2025-07-29
- Estimated Expiration
- 2041-12-17
AI Technical Summary
The existing tea frost evaluation method fails to accurately consider the dynamic changes in tea bud germination rate, resulting in large evaluation errors and cannot accurately reflect the impact of frost on tea output.
By establishing a forgetful curve model that simulates dormant cold adaptation memory in winter and a tea bud germination initial date prediction model, combining the tea bud germination rate temperature response curve model, the tea garden temperature data was interpolated using the support vector machine model to evaluate the tea frost index.
It realizes accurate determination of the tea bud germination period, reduces evaluation errors, provides a scientific basis for evaluating tea frost loss, and improves evaluation accuracy and applicability.
Smart Images
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Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of agricultural loss assessment, and more specifically to a method for evaluating the tea frost index. Background Art
[0002] The tea tree is a perennial plant. Evaluating the freezing injury rate of tea buds caused by the spring frost process is different from that of other crops. First, due to the different winter temperatures every year, the dormancy period in tea buds varies greatly between years. Second, the temperature fluctuates greatly in late winter and early spring. The length of the ecological dormancy of tea buds is determined by the competition result between the effective accumulated temperature during the ecological dormancy period and the low temperature accumulation value below the threshold temperature when the tea buds start internal dormancy. Third, tea is made from tea buds that reach a certain standard after germination. After the tea buds start to germinate, the germination rate of tea buds is a dynamic increasing process. Therefore, the injury rate of tea buds caused by frost at different tea bud germination periods is different, and the economic output of tea is different.
[0003] Currently, the tea frost assessment method adopted in China uses the effective accumulated temperature, determines the tea bud germination period (or the picking period) by a certain threshold temperature or by using the average temperature of a certain period, without considering the dynamic change process of the tea bud germination rate, which will cause a large error between the frost loss assessment value and the actual value.
[0004] First, an assessment method for the frost loss corresponding to the tea bud germination period determined by the effective accumulated temperature. Suppose the temperature in late winter and early spring rises steadily in the first year, and the tea buds start to germinate when the effective accumulated temperature above 10°C reaches 100°C.day. However, in the second year, when the effective accumulated temperature above 10°C reaches 60°C.day, there is a low temperature weather with a temperature below 5°C for several consecutive days. In the second year, the tea buds may start to germinate when the effective accumulated temperature above 10°C reaches 120°C.day (or even more).
[0005] Second, an assessment method for the frost loss corresponding to the tea bud germination period determined by a certain threshold temperature. Since the end time of the internal dormancy of tea buds and the temperature changes before and after passing through the threshold temperature are not considered, the determined picking period has a large difference from the actual value.
[0006] Third, an assessment method for the frost loss corresponding to the tea bud germination period determined by the average temperature of a certain period. The temperature fluctuates greatly in late winter and early spring. Since the temperature changes before and after this period are not considered, the determined picking period has a large difference from the actual value.
[0007] Fourth, a frost loss assessment method that does not consider the dynamic change process of the tea bud germination rate. The germination of tea buds is a dynamic process. This method cannot accurately evaluate how many tea buds are damaged by the frost process, resulting in a large error between the loss assessment value of tea frost to the tea output and the actual value.
[0008] Due to the lack of a reasonable loss assessment method, there is a large error in loss assessment, and it cannot correctly reflect the tea frost situation in a certain area. Summary of the Invention
[0009] The purpose of the present invention is to provide an assessment method that can accurately evaluate the damage of spring frost to tea buds in a tea garden in view of the deficiencies of the prior art.
[0010] A tea frost index assessment method includes the following steps:
[0011] 1) Collect meteorological data of the tea production area, tea tree variety information, tea bud dormancy data, tea bud sprouting data, data on the damage of tea tree buds and leaves during the process of meteorological disasters, phenological period data reflecting the growth of tea tree buds and leaves, and daily production data of tea from the start of spring tea picking to the end of spring tea picking;
[0012] 2) Establish a tea frost index according to the collected meteorological data of the tea production area, tea tree variety information, and data on the damage of tea buds during the process of meteorological disasters;
[0013] 3) Establish a forgetting curve model for simulating the cold adaptation memory of tea buds during winter dormancy and a prediction model for the initial date of tea bud germination according to the collected data;
[0014] 4) Establish a temperature response curve model for the germination rate of tea buds according to the collected data;
[0015] 5) Determine the germination rate of tea buds according to meteorological conditions;
[0016] 6) Evaluate the tea frost index according to the germination rate of tea buds and the meteorological indicators of tea frost.
[0017] As a further improvement and supplement to the above solution, the present utility model further includes the following additional technical features:
[0018] In step 2, the tea frost index is divided into 10 levels according to the percentage of frost-damaged buds on the tea tree canopy per unit area in the total number of buds, and 0 indicates that the tea buds are not frost-damaged.
[0019] In step 3, during the cold acclimation process of tea buds during winter dormancy, the effective low-temperature cumulative amount (CR t ) on a given date t is determined by the following formula:
[0020]
[0021] In the formula, n is the number of days since entering the dormancy period, n = 1 represents the first day of entering the dormancy period, T a,n is the daily average temperature on the nth day, T ta is the threshold temperature when the tea tree starts internal dormancy in autumn, and k and c are the forgetting curve model parameters.
[0022] CRt Reaching the low - temperature cumulative amount value (CR de ) required for the end of endodormancy within the tea tree variety or the sunshine duration reaching the sunshine duration (P de ) required for the end of endodormancy within the tea tree variety, the tea buds enter ecological dormancy from endodormancy. The effective accumulated temperature (GDD de ) of the tea buds on the de - th day of entering ecological dormancy is determined by the following formula:
[0023]
[0024] In the formula, T e is the threshold temperature value during the ecological dormancy of the tea buds. Let:
[0025] AF t = CR end+de + GDD de (3)
[0026] In the formula, end is the number of days of endodormancy. When AF t reaches the critical value (AFct), the ecological dormancy is released, and the tea buds begin to germinate (that is, the germination rate of the tea buds exceeds 0% for the first time).
[0027] In step 4 described above, the germination rate (P b,t ) of the tea buds on the t - th day after the tea buds begin to germinate is determined by the following formula:
[0028]
[0029] In the formula, T 50 is the daily average temperature when the germination rate of the tea buds reaches 50% in a day, T a,t is the daily average temperature on the t - th day, a is the parameter of the germination rate temperature response curve model (logistic model); when t - 1 = 0, P b,0 = 0.
[0030] In steps 3 and 4 described above, the parameters in the forgetting curve model for simulating the cold - adaptation memory of tea bud winter endodormancy, the prediction model for the initial date of tea bud germination, and the logistic curve model for the temperature response of tea bud germination rate are evaluated by minimizing the root - mean - square error (RMSE) between the estimated value and the observed value of the tea bud germination rate, and the double - cross - validation model parameters are used.
[0031] In step 5 described above, according to the historical daily average temperature and daily minimum temperature data, combined with the data of meteorological observation stations within a distance of 6 km and the digital elevation model (DEM), a fitting model of the daily average temperature and daily minimum temperature varying with topography is established using the support vector machine model, and 5×5m 2The daily average temperature and daily minimum temperature on the grid, and the predicted temperature data are interpolated to a 5×5m grid using intelligent grid prediction data, digital elevation model (DEM), and support vector machine model. 2 on the grid.
[0032] In step 2 described above, the meteorological index for the germinated tea buds damaged by frost is that the air temperature at 1.5m above the ground where the tea tree is located ≤ 0°C.
[0033] Using the present invention can achieve the following beneficial effects:
[0034] 1. The germination period of tea buds is determined by adopting the forgetting curve model simulating the cold adaptation memory of tea buds during winter dormancy and the prediction model of the initial date of tea bud germination. Compared with determining the germination period by using effective accumulated temperature, passing a certain threshold temperature, or using the average air temperature during a certain period, the determined germination period is consistent with the actual value.
[0035] 2. By adopting the evaluation method for the dynamic change process of tea bud germination rate, compared with the frost loss evaluation method that does not consider the dynamic change process of tea bud germination rate, the error of frost loss evaluation caused by the dynamic change of tea bud germination is avoided.
[0036] In summary, the method of the present invention can accurately evaluate the impact of spring frost on the economic output of tea leaves, has high precision and applicability, and can evaluate the injury rate of tea buds caused by frost in real time, providing a scientific basis for reducing the economic loss of tea leaves caused by frost. Description of the Drawings
[0037] Figure 1 is the flow chart of the present invention.
[0038] Figure 2 is the flow chart for determining the frost index of grid tea buds in the present invention.
[0039] Figure 3 is the weather statistical chart of Xinchang, Zhejiang in the present invention.
[0040] Figure 4 is the temperature statistical chart of Daming Tea Farm in Xinchang, Zhejiang from March 2 to March 16 in the present invention. Detailed Embodiments
[0041] The following describes the detailed embodiments of the present invention with reference to the drawings.
[0042] As Figures 1-4 shown, the present invention is a method for evaluating the tea leaf frost index.
[0043] First, the dormancy period of tea trees will be explained below.
[0044] Dormancy refers to the temporary cessation of visible growth of plant structures containing meristems. It is a periodic stage in plant development and a biological adaptation formed during plant evolution in response to environmental conditions and seasonal climate changes. Tea plants are perennial plants. In winter, they have to encounter severe cold. To survive, they must enhance their cold resistance through bud dormancy to adapt to the severe cold during the overwintering period. Endodormancy refers to dormancy controlled by the external structure of plants and regulated by physiological factors within the dormant structure itself (such as the need for low temperature and photoperiod response). Even when environmental conditions are favorable and there are no restrictions from nearby organs, the dormant structure cannot grow, and the influence of exogenous growth hormones is extremely weak at this time. When the temperature drops below a certain level in autumn or the day length is less than a certain duration, tea buds enter endodormancy. After tea buds enter endodormancy, when a certain chilling requirement is met or the day length is greater than a certain duration, the endodormancy of tea buds is released, and they enter ecodormancy. Ecodormancy refers to dormancy caused by environmental conditions, such as nutrient deficiency, water stress, light, oxygen deficiency, and unsuitable temperature, etc. After tea buds enter ecodormancy, when a certain heat condition is met, the tea buds resume growth and begin to germinate.
[0045] Generally, when the average daily temperature of the new shoots of tea plants is around 10°C, they begin to germinate. When it reaches 14 - 16°C, they start to elongate, the leaves unfold, and when it is 17 - 30°C, they grow rapidly. If the temperature drops below 10°C, the tea buds stop growing. For the new shoots of tea plants under picking conditions, the average growth period for each round is generally about 40 days. However, due to differences in varieties, climate, and other factors, it can be as short as more than 30 days or as long as 70 - 80 days. It takes from 2 - 3 days to 15 - 18 days, generally about 7 days, to unfold a new leaf. In most tea-growing areas in China with distinct seasons, the formation of new shoots is seasonal. From the germination of tea buds in spring to dormancy in winter, it takes 7 - 9 months. In the southern tea-growing areas of China (such as Hainan Island, etc.), although there are still growth periods and rest periods distinguishable on the same new shoot. However, due to the relatively high temperature throughout the year, for the same tea plant, new shoots can germinate and grow continuously throughout the year. Only because of the uneven distribution of rainfall (with dry and rainy seasons), the growth of new shoots is faster or slower, but there is no obvious dormancy period. In the northern tea-growing areas with long and cold winters (such as Shandong), the growth period of tea buds is 5 - 6 months, and they are in a dormant state for nearly 6 - 7 months.
[0046] Currently, for tea plant dormancy, tea plants are cultivated in the region between 49° north latitude and 35° south latitude. Near the equator or in areas close to the equator, the monthly yield distribution of tea plants is relatively balanced throughout the year. However, in areas far from the equator with distinct seasons, tea plants enter a dormant state in winter. Generally speaking, the dormant time increases with the increase in latitude.
[0047] Tea plants also rely on dormancy (forced dormancy) to endure unsuitable environments, enabling the smooth progression of their life cycles. In most tea-producing areas of China, when the late autumn temperature is still within the range suitable for the growth of tea buds, the tea plants stop sprouting, and the photosynthetic products produced by the branches and leaves are mainly stored in the roots and stems. After winter sets in, the starch stored internally is converted into sugar to increase the concentration of cell sap and enhance the cold resistance of the plants. After the tea plants enter forced dormancy, the growing buds are surrounded by waxy scales, forming so-called winter buds. These scales play a mechanical protective role for the buds, preventing the winter buds from losing water and facilitating safe overwintering.
[0048] After the tea plants overwinter, when the spring temperature rises, they repeat the activities of the second annual cycle.
[0049] The two main factors for the winter dormancy of tea plants are temperature and daylength. It cannot be entirely attributed to low temperature. Because in the high-altitude areas near the equator, although the temperature there is even higher than that in the plain areas in winter, the tea plants sprout new shoots throughout the year; on the contrary, there is a three-month dormancy period in this plain area. In the vast tea-producing areas of China with distinct seasons, although the temperature is still within the range suitable for the growth of tea buds in the late autumn season, the new shoots have long stopped sprouting. This shows that the dormancy of tea plants is also controlled by daylength.
[0050] Based on the data of monthly yields and average daylengths in some tea-growing areas from the equator to the north or south latitudes, when the daytime in winter is at least six weeks shorter than the critical value of 11 hours and 15 minutes, the tea plants will enter a complete dormancy period. The longer the duration of this night, the longer the dormancy period. From the observation of the growth process of new shoots of tea plants in Hangzhou, this critical value is during the Frost's Descent season (late October), with the daytime sunshine duration being 11 hours and 13 minutes, and the tea plants are gradually entering dormancy. Therefore, the winter dormancy of tea plants may be the result of short daylight (or long night) affecting the internal growth regulators of the tree body. Of course, daylength and low temperature usually affect each other as well.
[0051] The method for evaluating the tea leaf frost index described in this embodiment includes the following steps:
[0052] 1) Collect meteorological data of the tea production area, tea tree variety information, tea bud dormancy data, tea bud sprouting data, data on the damage of tea tree buds and leaves during the process of meteorological disasters, phenological data reflecting the growth of tea tree buds and leaves, and daily production data of tea leaves from the start of spring tea picking to the end of spring tea picking;
[0053] For example, the weather statistics of Xinchang, Zhejiang are shown in the appendix Figure 3 :
[0054] For example, on March 2, 2019, the Wuniuzao tea trees in the Daming Tea Farm in Xinchang, Zhejiang entered the picking period, and the temperature in the Daming Tea Farm in March is shown in the appendix Figure 4 :
[0055] The more detailed the data collection is, the closer the evaluated value is to the reality.
[0056] 2) Establish a tea leaf frost index based on the meteorological data of the tea production area, the information of tea tree varieties, and the data of tea bud damage during the process of meteorological disasters affecting tea production.
[0057] 3) Establish a forgetting curve model for simulating the cold adaptation memory of tea buds during winter dormancy and a prediction model for the initial date of tea bud germination based on the collected data.
[0058] 4) Establish a temperature response curve model for the germination rate of tea buds based on the collected data.
[0059] 5) Determine the germination rate of tea buds according to the meteorological conditions.
[0060] 6) Evaluate the tea leaf frost index based on the germination rate of tea buds and the meteorological indicators of tea leaf frost.
[0061] Furthermore, in step 2, the tea leaf frost index is divided into 10 levels according to the percentage of frost-damaged buds on the tea tree canopy per unit area in the total number of buds. 0 indicates that the tea buds are not frost-damaged. From level 1 to level 10, the larger the value, the larger the percentage of frost-damaged buds in the total number of buds.
[0062] Furthermore, in step 3, during the cold acclimation process of tea buds in winter dormancy, the effective low-temperature accumulation amount (CR t ) on a given date t is determined by the following formula:
[0063]
[0064] In the formula, n is the number of days since entering the dormancy period. n = 1 represents the first day of entering the dormancy period. T a,n is the daily average temperature on the nth day. T ta is the critical temperature when the tea tree starts internal dormancy in autumn. k and c are the parameters of the forgetting curve model.
[0065] CR t reaches the value of the low-temperature accumulation amount required for the end of internal dormancy of the tea tree variety (CR de ) or the sunshine duration reaches the sunshine duration required for the end of internal dormancy of the tea tree variety (P de ), then the tea buds enter ecological dormancy from internal dormancy. The effective accumulated temperature (GDD de ) on the de-th day when the tea buds enter ecological dormancy is determined by the following formula:
[0066]
[0067] In the formula, T e is the critical temperature value during the ecological dormancy of the tea buds. Let:
[0068] AF t = CRend+de + GDD de (3)
[0069] where end is the number of days of internal dormancy. When AF t reaches the critical value (AFct), the ecological dormancy is released, and the tea buds begin to germinate (i.e., the germination rate of tea buds exceeds 0% for the first time).
[0070] Furthermore, in step 4, the germination rate (P b,t ) on the t-th day after the tea buds begin to germinate is determined by the following formula:
[0071]
[0072] where T 50 is the daily average temperature when the germination rate of tea buds reaches 50% in a day, T a,t is the daily average temperature on the t-th day, and a is the parameter of the germination rate temperature response curve model (logistic model); when t - 1 = 0, P b,0 = 0.
[0073] Taking the evaluation of the frost index of Wuniuzao tea trees in Mingfu Tea Farm, Xinchang County, Zhejiang Province as an example, according to the historical tea tree growth data, the parameters in formulas (1) to (4) are determined as shown in Table 1.
[0074] Table 1 Parameters in Formulas (1) to (4)
[0075] parameter <![CDATA[T ta > k c <![CDATA[T e > <![CDATA[CR de > <![CDATA[AF ct > <![CDATA[T 50 > a value 9.7℃ 12.1 3.2 -3.7℃ -184.6℃.d 56.3℃.d 31.9℃ -0.137
[0076] The critical sunshine duration (P de ) for the tea tree to end dormancy is 11:15, which occurred on February 17 in Mingfu Tea Farm, Xinchang County.
[0077] The tea leaf frost index is shown in Table 2.
[0078] Table 2 Tea leaf frost index and corresponding tea bud frostbite rate
[0079]
[0080] On December 11, 2020, the daily average temperature stably passed 9.7°C, and the Wuniuzao tea trees in Mingfu Tea Farm, Xinchang County entered the internal dormancy period on December 11. According to the data of the meteorological station in Mingfu Tea Farm and formula (1), the effective low-temperature cumulative amount (CR t)Reaching -185.1 °C, the Wuniuzao tea trees ended their endogenous dormancy on that day and entered the ecological dormancy state. According to the calculations using formula (2) and formula (3), the AFt values on February 8th, 9th, and 10th, 2021 were 47.0 °C·d, 56.3 °C·d, and 65.8 °C·d respectively, and the tea buds of Wuniuzao tea trees began to germinate on February 9th. The daily germination rate of tea buds calculated according to formula (4) is shown in Table 3.
[0081] Table 3 Daily Germination Rate of Wuniuzao Tea Trees in Mingfu Tea Farm
[0082]
[0083] On February 18th, the minimum temperature at the meteorological station in Mingfu Tea Farm was -3.2 °C, causing the germinated tea buds on that day to be frostbitten. It can be seen from Table 3 that the frostbite rate of tea buds was 45.6%. Corresponding to Table 2, the frost index of Wuniuzao tea trees at the location of the meteorological station in Mingfu Tea Farm during this frost process was 5.
[0084] Furthermore, in steps 3 and 4, for the parameters in the forgetting curve model simulating the cold acclimation memory of tea buds during winter endogenous dormancy, the prediction model for the initial date of tea bud germination, and the logistic curve model for the temperature response of tea bud germination rate, they are evaluated by minimizing the root mean square error (RMSE) between the estimated value and the observed value of the tea bud germination rate, and the double cross-validation model parameters are adopted.
[0085] Furthermore, in step 5, based on the historical daily average temperature and daily minimum temperature data, combined with the data of meteorological observation stations within a distance of 6 km and the digital elevation model (DEM), a fitting model of the daily average temperature and daily minimum temperature varying with terrain is established using the support vector machine model, and the daily average temperature and daily minimum temperature on a 5×5 m 2 grid are calculated. The predicted temperature data are interpolated to a 5×5 m 2 grid using the intelligent grid prediction data, the digital elevation model (DEM), and the support vector machine model.
[0086] Considering the inconsistent spatial distribution of temperature caused by the undulating terrain of the tea garden, based on the historical daily average temperature and daily minimum temperature data, combined with the data of meteorological observation stations within a distance of 6 km and the digital elevation model (DEM), a fitting model of the daily average temperature and daily minimum temperature varying with terrain is established using the support vector machine model, and the daily average temperature and daily minimum temperature on a 5×5 m 2 grid are calculated. The predicted temperature data are interpolated to a 5×5 m 2 grid using the intelligent grid prediction data, the digital elevation model (DEM), and the support vector machine model. The daily average temperature and daily minimum temperature data are interpolated to a 5×5 m 2On the grid, the tea bud germination rate of each grid is calculated by combining formulas (1) to (4), and the frost index of each grid during the low-temperature frost process is obtained according to the lowest temperature value of each grid. The specific process and flow are shown in Figure 2 as shown.
[0087] Furthermore, in step 2, the meteorological index of the germinated tea buds damaged by frost is that the temperature at 1.5 m above the ground where the tea tree is located is ≤ 0 °C.
[0088] For different varieties of tea trees and different origins, the parameter values are often inconsistent. Scientific calculations and evaluations are carried out according to the formulas and the corresponding values to calculate the frost index, providing a scientific basis for reducing the economic losses of tea caused by frost.
[0089] The above is the preferred embodiment of the present invention, which does not limit the protection scope of the present invention. Any variations and improvements made by those skilled in the art according to the design concept of the present invention should be regarded as within the protection scope of the present invention.
Claims
1. A method for evaluating the tea leaf frost index, characterized in that, Including the following steps: 1) Collect meteorological data of the tea production area, tea tree variety information, tea bud dormancy data, tea bud germination data, data on the damage of tea tree buds and leaves during the process of meteorological disasters, phenological data reflecting the growth of tea tree buds and leaves, and daily production data of tea from the start of spring tea picking to the end of spring tea picking; 2) Establish a tea frost index based on the collected meteorological data of the tea production area, tea tree variety information, and data on the damage of tea buds during the process of meteorological disasters; 3) Establish a forgetting curve model for simulating the cold adaptation memory of tea buds during winter dormancy and a prediction model for the initial date of tea bud germination based on the collected data; 4) Establish a temperature response curve model for tea bud germination rate based on the collected data; 5) Determine the tea bud germination rate according to meteorological conditions; 6) Evaluate the tea frost index based on the tea bud germination rate and tea frost meteorological indicators; In the step 3, during the cold acclimation process of winter endodormancy of tea buds, the effective low temperature cumulative amount CR at a given date t t is determined by the following formula: where n is the number of days entering the dormancy period, n = 1 represents the first day of entering the dormancy period, T a,n is the daily average temperature on the nth day, T ta is the threshold temperature when the tea tree begins internal dormancy in autumn, and k and c are the parameters of the forgetting curve model; CR t Reach the low temperature accumulation value CR required for the end of endodormancy within the tea tree variety de Or when the sunshine duration reaches the sunshine duration P required for the end of endodormancy within the tea tree variety de When this occurs, the tea buds enter ecodormancy from endodormancy, and the growing degree days GDD of the tea buds on the de-th day of entering ecodormancy de Is determined by the following formula: where T e is the threshold temperature value during the ecological dormancy period of tea buds; Let: AF t = CR end+de + GDD de (3) where end is the number of days of internal dormancy; when AF t reaches the critical value AFct, the ecological dormancy is released, and the tea buds begin to germinate, that is, the germination rate of tea buds exceeds 0% for the first time; In the step 4, the germination rate P on the t-th day after the tea buds begin to germinate b,t is determined by the following formula: where T 50 is the daily average temperature when the germination rate of tea buds reaches 50% in a day, T a,t is the daily average temperature on the t-th day, and a is the parameter in the logistic curve model of the temperature response of the tea bud germination rate; when t - 1 = 0, P b,0 = 0.
2. The method for evaluating the tea frost index according to claim 1, characterized in that: In step 2, the tea frost index is divided into 10 levels according to the percentage of frost-damaged buds on the tea tree canopy per unit area in the total number of buds, and 0 indicates that the tea buds are not frost-damaged.
3. The method for evaluating the tea frost index according to claim 1, wherein: In steps 3 and 4, the parameters in the forgetting curve model for simulating the cold adaptation memory of tea buds during winter dormancy, the prediction model for the initial date of tea bud germination, and the logistic curve model for the temperature response of tea bud germination rate are evaluated by minimizing the root mean square error RMSE between the estimated value and the observed value of the tea bud germination rate, and the double cross-validation model parameters are used.
4. The method for evaluating the tea frost index according to claim 1, wherein: In the aforesaid step 5, according to the historical daily average temperature and daily minimum temperature data, combined with the data of meteorological observation stations within a distance of 6 km and the digital elevation model DEM, a fitting model of the variation of the daily average temperature and the daily minimum temperature with the terrain is established by using a support vector machine model, and the daily average temperature and the daily minimum temperature on a 5×5 m 2 grid are calculated. The predicted temperature data are interpolated onto a 5×5 m 2 grid by using the intelligent grid prediction data, the digital elevation model DEM and the support vector machine model.
5. The method for evaluating the tea frost index according to claim 1, wherein: In step 2, the meteorological indicator for the frost damage of germinated tea buds is that the air temperature at 1.5 m above the ground at the location of the tea tree is ≤ 0°C.