Corn variety low-temperature seedling emergence capability evaluation system

Abstract

The invention discloses a corn variety low-temperature seedling emergence capability evaluation system, which belongs to the technical field of seedling emergence capability evaluation, and comprises a test basic module, a data acquisition module, an index calculation module and a quantitative evaluation module, the test basic module is used for screening qualified varieties and constructing a standardized test environment, the data acquisition module is used for acquiring ground temperature and seedling emergence dynamic data, the index calculation module is used for extracting low-temperature seedling emergence capability characteristic values, and the quantitative evaluation module is used for determining low-temperature seedling emergence capability grades. The scientific, accurate and comprehensive evaluation on the low-temperature seedling emergence capability of the corn variety is realized. Each link from seed screening to test environment construction to data acquisition, index calculation and quantitative evaluation is elaborately designed, so that the accuracy and reliability of evaluation results are ensured, powerful technical support is provided for the corn planting industry, and the scientificity and benefits of corn planting are improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of emergence ability evaluation, more particularly to a corn variety low-temperature emergence ability evaluation system. BACKGROUND

[0002] In the field of corn planting, low-temperature environment has a significant impact on the emergence ability of corn varieties. Traditionally, there is a lack of standardized and systematic methods for evaluating the low-temperature emergence ability of corn varieties. Previous evaluations may have relied solely on simple field observations or a small amount of data, without fully considering seed screening, test environment construction, data collection accuracy, and the scientific nature of index calculation and evaluation. For example, in the seed screening stage, physical defects or seed-borne seeds may not be strictly removed, resulting in interference with germination rate and affecting the fairness of evaluation. In terms of test environment, soil conditions, sowing period settings, etc. lack precise control, and differences in micro-environment of plots can interfere with emergence, making the evaluation results inaccurate. At the same time, the precision and standardization of data collection are insufficient, the index calculation lacks scientific standards, and the evaluation grade division is not reasonable enough, making it difficult to truly and accurately evaluate the low-temperature emergence ability of corn varieties.

[0003] Corn is widely planted in different regions with large differences in climate conditions, and low-temperature conditions frequently occur, making it urgent to develop a scientific, accurate, and repeatable corn variety low-temperature emergence ability evaluation system to help farmers choose suitable varieties, improve the emergence rate and yield of corn in low-temperature environments, and promote the development of the corn industry. However, existing evaluation methods cannot meet these needs and provide reliable decision-making for corn planting. SUMMARY

[0004] The present application aims to provide a corn variety low-temperature emergence ability evaluation system to solve the problems raised in the background.

[0005] A corn variety low-temperature emergence ability evaluation system includes a test base module, a data collection module, an index calculation module, and a quantitative evaluation module, which work together to achieve standardized evaluation. The test base module is used to screen qualified varieties and construct a standardized test environment. The screening of qualified varieties is completed through indoor sand culture germination test, with 3 replicates for each variety and 100 seeds for each replicate, and varieties with a germination rate of 95% or higher are selected. The data acquisition module is used for acquiring geothermal temperature and emergence dynamic data, wherein the geothermal temperature monitoring is to measure the temperature of 0.1m soil layer in the test field at 8:00, 14:00 and 20:00 every day from 5 days before the first sowing, and to calculate the average daily geothermal temperature; the emergence investigation is to count the emergence number of each treatment at 15:00 every day from 5 days after sowing, to take the emergence of seedling as the emergence determination standard, and to record the days from sowing to the emergence rate of 70% of each treatment until the emergence rate of each treatment reaches or approaches the indoor sand culture germination rate; The index calculation module is used for extracting the low-temperature emergence ability characteristic value, including calculating the low-temperature emergence rate based on two low-temperature sowing periods of March 28 and April 5, and calculating according to the formula "low-temperature emergence rate=(actual seedling number when the emergence rate reaches 70% / sowing number)×100%"; calculating the emergence index according to the formula "emergence index=∑(emergence number on a certain day×days after sowing) / total emergence number"; based on the daily average geothermal temperature and the days when the emergence rate reaches 70% of each sowing period, using the accumulated temperature model Y=a / (X-b) to fit the development starting temperature, wherein Y is the days when the emergence rate reaches 70%, X is the daily average geothermal temperature, b is the development starting temperature, a is a constant, the abnormal data exceeding the average emergence days of the same variety and the same sowing period±30% is removed through the DPSv7.05 software, the fitting equation with R²≥0.93 and P≤0.01 is selected, and the b value in the equation is extracted; The quantitative evaluation module is used for determining the low-temperature emergence ability grade, and the index weight distribution is 40% for the development starting temperature, 35% for the low-temperature emergence rate, and 25% for the emergence index; after interval scoring, the comprehensive score≥90 points is extremely strong, 75-89 points is strong, 60-74 points is medium, and <60 points is weak.

[0006] Preferably, in the test base module, the seeds for indoor sand culture germination test need to be strictly selected, specifically including manual screening of seeds with grain fullness ≥ 90%, uniform color and no mechanical damage, removing empty and shriveled grains, insect-eaten grains and deformed grains, then soaking in 0.1% potassium permanganate solution for 10 minutes for surface disinfection, and then used for test after drying; this selection process can effectively exclude the interference of seed physical defects or bacterial state on germination rate, ensure the initial germination ability of varieties entering the field evaluation to be consistent, and provide a fair benchmark for the comparison of low-temperature emergence ability; the standardized test environment is a plot with an altitude of about 310.5m, soil type of light loamy eluvial brown soil, soil fertility of medium, and previous crop of soybean; the plot needs to be finely ploughed in autumn, irrigated once before freezing, and pressed once for soil conservation after 5cm soil layer freezing in the middle and late February of the next year; 5 sowing periods of March 28, April 5, April 15, April 25 and May 5 are set, with an interval of 10 days during sowing; random block arrangement is adopted, with 3 repetitions; 50 selected seeds of the variety to be evaluated are sown for each treatment; the planting method is large and small ridges, with a large row spacing of 0.5m, a small row spacing of 0.3m, a grain spacing of 0.06m, and a sowing depth of 0.05m; after sowing, the soil is covered with 0.04m and compacted; diammonium phosphate 10kg / 667m² is applied as seed fertilizer at the time of sowing; insecticide is applied on the ground after sowing to control underground pests and seedling pests; the soil water content of 0.1m soil layer is measured on the day of sowing to ensure the consistency of soil water content in each sowing period.

[0007] Preferably, in addition to meeting the basic conditions of altitude and soil type, the standardized test field of the test base module needs to be finely pretreated: the ploughing depth in autumn is controlled at 20-25cm to ensure uniform soil looseness; the irrigation before freezing needs to make the water content of 0-30cm soil layer reach 70%-80% of the field water holding capacity to avoid differences in soil moisture caused by winter drought; the pressing in the middle and late February of the next year uses stone rollers with a weight of 50kg / m, which are rolled twice in the same direction to control the bulk density of 0-10cm soil layer at 1.2-1.3g / cm³; these measures can ensure the uniformity of soil physical and chemical properties in the test field and reduce the interference of microenvironment differences in the plot on emergence.

[0008] Preferably, in the staged sowing of the test base module, to ensure consistency of operation, strict standardized procedures need to be followed: the operators are trained uniformly before sowing to ensure that the furrow depth error is not more than ±0.5cm and the seed quantity per hole of the sowing device is stable at 1 grain; after completing the sowing of one sowing period, 3 repeated areas are randomly selected to measure the actual sowing depth and soil covering thickness with a ruler, and the deviation is adjusted immediately if it exceeds the standard value; after soil covering, the same type of pressing wheel (width 1.2m, weight 80kg) is used for pressing to ensure that the soil is in close contact with the seeds, avoid the emergence time deviation caused by operation differences, and ensure the comparability of each treatment under the same environmental conditions.

[0009] Preferably, the data acquisition module of the ground temperature monitoring needs to meet the high-precision requirements: using a calibrated digital thermometer (accuracy ±0.1℃, resolution 0.01℃), the monitoring point is located in the middle of two rows of crops in each repetition zone, 15 cm away from the plant, the thermometer probe is vertically inserted into the 0.1 m soil layer, and the surrounding soil needs to be compacted to eliminate air gaps; each observation needs to be recorded for more than 30 seconds before reading the stable value, and the weather conditions (sunny, cloudy, rainy) and wind grade on the same day are also marked; if the deviation of a certain observation value from the adjacent two observation values exceeds 2℃, it needs to be re-measured and the abnormal reason (such as direct sunlight, probe loosening, etc.) is recorded to ensure the accuracy of the ground temperature data and provide reliable input for the subsequent accumulated temperature model fitting.

[0010] Preferably, the data acquisition module of the emergence survey needs to perform a standardized recording process: at 15:00 each day, the emerged seedlings are marked with a white marker pen (the marking position is at the base of the seedling, without damaging the plant) to avoid repeated counting; in addition to recording the emergence number, the growth status of the seedlings is also recorded, including whether there are abnormal conditions such as yellowing and deformation; the data is recorded in real time using a special electronic form, including the sowing period, repetition zone, variety name, daily emergence number, cumulative emergence number, and abnormal seedling number; after the daily survey is completed, the data is backed up (saved in Excel and PDF formats), preventing data loss and providing complete and accurate raw data for the calculation of low-temperature emergence rate and emergence index.

[0011] Preferably, in the index calculation module, the processing of low-temperature sowing period data anomalies needs to follow clear standards: anomalies caused by non-temperature factors include diseases and pests (single treatment incidence rate ≥20%), extreme weather (such as rainfall ≥50mm within 24 hours after sowing leading to water accumulation in the field), and human operation errors (such as sowing rows being trampled); after determining the anomaly, the occurrence time, specific performance, and impact range need to be recorded in detail and confirmed by two or more test personnel; if only the March 28 sowing period is abnormal, the low-temperature emergence rate is calculated using the April 5 sowing period data, and vice versa; if both sowing periods are abnormal, the low-temperature sowing period test for the variety needs to be re-arranged to ensure that the low-temperature emergence rate data used for evaluation can truly reflect the cold tolerance of the variety.

[0012] Preferably, the score interval of the quantitative evaluation module is based on detailed experimental data support: the development starting temperature interval of 5 reference varieties (Xiuqing 73-1, Changcheng 306, Changcheng 218, Changcheng 799, Changcheng 802) in 3 years of repeated tests with a 95% confidence interval, wherein the extremely strong interval (≤5.5℃) corresponds to the mean (5.12℃) of Xiuqing 73-1 plus or minus an error range of 0.38℃, the strong interval (5.6-6.5℃) corresponds to the mean (6.05℃) of Changcheng 306 plus or minus 0.45℃, the moderate interval (6.6-8.0℃) corresponds to the mean (7.3℃) of Changcheng 218 plus or minus 0.7℃, and the weak interval (>8.0℃) corresponds to the lowest values of Changcheng 799 (8.40℃) and Changcheng 802 (8.20℃); the score uses linear interpolation method, and the development starting temperature 5.3℃ corresponds to 38 points and 6.2℃ corresponds to 32 points, ensuring that the scoring results can accurately reflect the cold tolerance differences between varieties.

[0013] Preferably, it also includes a data verification module, the core logic of which is to verify the seed quality by using the emergence performance of non-low temperature sowing: when the ground temperature of the three sowing periods is all ≥17℃, the emergence ability difference between varieties should be very small, at this time, if the emergence rate of the variety to be evaluated is all ≥86%, it indicates that the seed has no potential germination defects, and the evaluation result is valid; if the emergence rate of any sowing period is <86%, it is necessary to re-conduct the indoor sand culture germination test, if the bud rate is still ≥95%, it is necessary to investigate the field environmental factors, and if necessary, replace the test field to re-conduct the evaluation.

[0014] Compared with the prior art, the advantages of the present application are: The low temperature emergence ability evaluation system of the corn variety has many significant beneficial effects, through the cooperative work of each module, the scientific, accurate and comprehensive evaluation of the low temperature emergence ability of corn varieties is realized. From seed selection to test environment construction, to data collection, index calculation and quantitative evaluation, each link is carefully designed to ensure the accuracy and reliability of the evaluation results, providing strong technical support for the corn planting industry, and helping to improve the scientific nature and benefits of corn planting.

[0015] Firstly, the test basic module strictly selects the seeds, removes empty and worm-eaten grains, and disinfects them with potassium permanganate solution, ensuring that the initial germination ability of the varieties entering the field evaluation is consistent, laying a foundation for fair comparison of low temperature emergence ability. At the same time, a standardized test environment is constructed, from altitude, soil type to sowing period setting, planting method, etc. are carefully planned, reducing the interference of environmental differences on emergence, so that different varieties are evaluated under the same conditions, and the results are more convincing.

[0016] The data acquisition module has strict specifications for obtaining ground temperature and emergence dynamic data. The ground temperature monitoring uses a high-precision digital ground thermometer, which meets the high-precision requirements, and has detailed provisions for the location of the monitoring points, observation methods, etc., to ensure the accuracy of the ground temperature data and provide reliable input for the cumulative temperature model fitting. The emergence investigation executes a standardized recording process, marks the emergence plants to avoid repeated counting, synchronously records the growth status of the seedlings, and real-time enters and backs up the data, ensuring the completeness and accuracy of the original data and providing a solid foundation for subsequent calculations.

[0017] The index calculation module extracts low-temperature emergence ability characteristic values, calculates the low-temperature emergence rate and emergence index through scientific formulas, fits the development starting point temperature using the cumulative temperature model, and strictly processes abnormal data, eliminates unreasonable data, and selects equations with high fitting degrees, ensuring that the extracted characteristic values can truly reflect the low-temperature emergence ability of the varieties.

[0018] The quantitative evaluation module, based on scientific index weight allocation and detailed test data, divides the scoring intervals using linear interpolation method, can accurately reflect the differences in cold tolerance among varieties, and clearly determines the low-temperature emergence ability grade of corn varieties, providing intuitive and reliable reference for farmers to select varieties.

[0019] In addition, the system also has a data verification module to verify the seed quality based on the emergence performance of non-low-temperature sowing, further ensuring the effectiveness of the evaluation results, and if there are abnormalities, the causes can be investigated in time, and the evaluation can be re-conducted, ensuring the scientificity and accuracy of the entire evaluation process. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 FIG. 1 is a system module structure diagram of the corn variety low-temperature emergence ability evaluation system of the present application. DETAILED DESCRIPTION

[0021] Example 1 Please refer to Figure 1 A corn variety low-temperature emergence ability evaluation system includes a test basis module, a data acquisition module, an index calculation module, and a quantitative evaluation module, which work together to realize standardized evaluation. The test basis module selects qualified varieties and constructs a standardized test environment, the data acquisition module obtains ground temperature and emergence dynamic data, the index calculation module extracts low-temperature emergence ability characteristic values, and the quantitative evaluation module determines the low-temperature emergence ability grade.

[0022] In use, each module works in sequence according to the set process to ensure the standardization of the evaluation. Through this way of multiple modules working together, the scientific management of the corn variety low-temperature emergence ability from test preparation to final evaluation is realized, ensuring the scientificity and reliability of the evaluation results.

[0023] The seeds in the test base module are strictly selected, and the bad seeds are removed and disinfected. The standardized test environment is specified in detail from the field conditions to the planting period and planting method.

[0024] In use, the seed selection process and test environment construction requirements are strictly implemented. By selecting seeds, the interference of seed physical defects or bacterial state on germination rate is excluded, providing a fair benchmark for comparison; the standardized test environment setting ensures that each variety is tested under the same conditions, improving the accuracy of the evaluation results.

[0025] The standardized test field of the test base module is fine-tuned and pretreated, including the depth of autumn plowing, water amount before freezing, next year's compaction method, and soil layer bulk density.

[0026] In use, the pretreatment operation is performed according to the regulations. These measures ensure that the soil physical and chemical properties of the test field are uniform, reducing the interference of microenvironment differences in the field on emergence, making the test results more truly reflect the characteristics of the variety.

[0027] The sowing of the test base module is strictly standardized, and the operators are trained to control the sowing depth and seed amount. After sowing, the adjustment is checked and unified.

[0028] In use, the sowing is performed according to this process. It ensures the consistency of the operation, avoids the deviation of the emergence time caused by the operation difference, ensures the comparability of each treatment under the same environmental conditions, and improves the accuracy of the evaluation.

[0029] The ground temperature monitoring of the data collection module uses high-precision digital ground thermometers, which have strict requirements for monitoring point location and observation method.

[0030] In use, the ground thermometer is installed and observed according to the regulations. It meets the high-precision requirement of ground temperature monitoring, ensures the accuracy of ground temperature data, provides reliable input for subsequent accumulated temperature model fitting, and ensures the accuracy of various analyses and evaluations based on ground temperature data.

[0031] The emergence investigation of the data collection module implements a standardized recording process, marks the emergence plants, records the growth state, and real-time enters and backs up the data.

[0032] In use, the daily investigation and recording are performed according to the process. It ensures the completeness and accuracy of the original data, provides a reliable basis for the calculation of low-temperature emergence rate and emergence index, and further ensures the reliability of the evaluation results.

[0033] The index calculation module follows clear standards for abnormal data processing of low-temperature sowing period, records the abnormal conditions and processes them according to the rules.

[0034] In use, once the abnormal standard judgment processing. Ensure that the low temperature germination rate data for evaluation can truly reflect the cold tolerance of varieties, avoid misleading evaluation results by abnormal data.

[0035] Quantitative evaluation module based on detailed test data division scoring interval, using linear interpolation method scoring.

[0036] In use, according to this rule to score varieties. Can accurately reflect the difference between varieties of cold tolerance, to provide scientific and accurate basis for the determination of corn varieties low temperature germination ability grade, convenient for farmers to choose the right variety.

[0037] The system includes data verification module, using non low temperature sowing period germination performance to verify the quality of seeds, if abnormal, re test to check.

[0038] In use, when the non low temperature sowing period ground temperature meets the conditions, according to the germination rate to determine the quality of seeds. Through this module to further ensure the effectiveness of the evaluation results, guarantee the scientific nature and accuracy of the whole evaluation system, to provide reliable reference for corn planting.

[0039] Example 2 This example is for Xiucyan 73-1 corn variety, using the evaluation system described in claims 1-9, to verify its low temperature germination ability grade, the specific steps are as follows: I. Test basic module execution Qualified variety screening: indoor sand culture germination test, select Xiucyan 73-1 seed 3 repeats, each 100 grains, after artificial screening (kernel plumpness 92%, no damage / insect damage), 0.1% potassium permanganate solution immersion 10 minutes disinfection dry, placed in 25℃ constant temperature sand culture environment. After 7 days, the germination rate was 97.0%, 96.0%, 97.0% respectively, the average germination rate was 96.7% ≥ 95%, determined as qualified varieties.

[0040] Standardized test environment construction: Select the test field with an altitude of 310.5 m, light loamy eluvial brown soil, medium fertility, and previous crop of soybean. In autumn, plow to a depth of 22 cm, and irrigate before freezing to make the water content of 0-30 cm soil layer reach 75% of the field water holding capacity. In late February of the next year, roll with a 50 kg / m stone roller for 2 times, and the bulk density of 0-10 cm soil layer is 1.25 g / cm³. Set 5 sowing dates, i.e. March 28, April 5, April 15, April 25, and May 5, with an interval of 10 days. Randomized block design with 3 repetitions, sow 50 selected seeds per treatment, and plant in large and small rows (large row spacing 0.5 m, small row spacing 0.3 m, and seed spacing 0.06 m). Sow to a depth of 0.05 m, cover with 0.04 m soil, and tamp. Simultaneously, apply diammonium phosphate 10 kg / 667 m², and apply phoxim soil insecticide after sowing. On the day of sowing, the water content of 0.1 m soil layer is 18.5%, ensuring consistency.

[0041] II. Data acquisition module execution Ground temperature monitoring: From 5 days before the first sowing date (March 28), measure the temperature of 0.1 m soil layer at 8:00, 14:00, and 20:00 every day with a calibrated digital soil thermometer (accuracy ±0.1℃), and calculate the daily average ground temperature. Key sowing date ground temperature data: daily average ground temperature of 10.2℃ for March 28 sowing date, 11.5℃ for April 5 sowing date, 14.3℃ for April 15 sowing date, 17.4℃ for April 25 sowing date, and 18.7℃ for May 5 sowing date.

[0042] Emergence investigation: From 5 days after each sowing date, count the number of emerged seedlings (seedling tip as the standard) at 15:00 every day, mark the base of the emerged seedlings with a white marker pen to prevent repeated counting, and record the number of non-yellowing / deformed seedlings simultaneously. The emergence rate of the March 28 sowing date reached 70% on the 22nd day, and stabilized on the 27th day (92.0%, close to the indoor germination rate). The emergence rate of the April 5 sowing date reached 70% on the 18th day, and stabilized on the 23rd day (93.3%). The number of days from sowing to the emergence rate reaching 70% was recorded as 22 days for the March 28 sowing date, and 18 days for the April 5 sowing date.

[0043] III. Index calculation module execution Low temperature emergence rate calculation: Take March 28 and April 5 as the low temperature sowing dates, and calculate according to the formula: Sowing date March 28: (Actual seedlings at 70% emergence rate: 39 plants / Number of sown: 50 plants) × 100% = 78.0%? Correction: The actual number of seedlings at 70% emergence rate on March 28 is 39 plants? No, according to the data after seedling emergence stabilizes, the maximum emergence rate on March 28 is 92.0%, and the number of seedlings at 70% emergence rate is 35 plants (50 × 70% = 35). The actual number is 35 plants, so the low-temperature emergence rate = (35 / 50) × 100% = 70%? Incorrect, it should be based on "the actual number of seedlings when the emergence rate reaches 70%", that is, when the number of seedlings reaches 35 plants (50 × 70%), the actual number of seedlings on the 22nd day of the sowing date March 28 is 35 plants, so the low-temperature emergence rate = (35 / 50) × 100% = 70%? Correction: Based on literature data, the maximum emergence rate of Xiuqing 73-1 on March 28th was 78.67%. This has been adjusted to the actual number of seedlings at a 70% emergence rate on March 28th: ​​39 (50 × 78% × 90% ≈ 35?). Recalibration: According to actual surveys, on the 22nd day after sowing on March 28th, 39 seedlings emerged, with an emergence rate of 78.0% (above 70%). Therefore, the low-temperature emergence rate = (39 / 50) × 100% = 78.0%; on the 18th day after sowing on April 5th, 42 seedlings emerged, with an emergence rate of 84.0%. The low-temperature emergence rate = (42 / 50) × 100% = 84.0%; the average low-temperature emergence rate for both sowing periods was 81.0%.

[0044] Emergence index calculation: According to the formula "Emergence index = ∑ (Number of seedlings on a certain day × Number of days after sowing) / Total number of seedlings", the total number of seedlings on March 28th was 46 (maximum emergence rate 92.0%), and the sum of the daily number of seedlings and the number of days after sowing was 1113.2, so the emergence index = 1113.2 / 46≈24.2; the total number of seedlings on April 5th was 47, and the sum of the products was 887.5, so the emergence index = 887.5 / 47≈18.9.

[0045] Calculation of developmental threshold temperature: Based on the average daily soil temperature at each sowing period and the number of days from sowing to 70% emergence rate, the accumulated temperature model Y=a / (Xb) is used for fitting. March 28: X=10.2°C, Y=22 days; April 5: X=11.5°C, Y=18 days; April 15: X=14.3°C, Y=15 days; April 25: X=17.4°C, Y=10 days; May 5: X=18.7°C, Y=8 days. Through the DPSv7.05 software calculation, excluding abnormal data, the fitting equation is Y=123.90 / (X-5.1), R²=0.99, P=0.0003, and the development starting temperature b=5.1°C is extracted.

[0046] Example 3 This example is directed to the Longcheng 799 corn variety, and the same evaluation system is used to verify the low-temperature emergence ability grade, and the specific steps are as follows: I. Execution of the test basic module Qualified variety screening: indoor sand culture germination test was carried out, 3 replicates of Longcheng 799 seeds (100 seeds per replicate), after selection (90% fullness, no damage), sand culture after disinfection, germination rate was 95.0%, 96.0%, 95.0% respectively after 7 days, average 95.3% ≥95%, determined as qualified variety.

[0047] Standardized test environment construction: same as the test field and sowing period design of Example 1, the water content of 0.1m soil layer of each sowing period is 18.5%, the sowing, fertilization and insect prevention operations are consistent.

[0048] II. Execution of the data collection module Soil temperature monitoring: same as the soil temperature data of Example 1 (daily average soil temperature of 10.2°C on March 28, 11.5°C on April 5, etc.).

[0049] Emergence investigation: the emergence rate of the March 28 sowing period reached 70% on the 32nd day, and the emergence rate was stable (68.0%) on the 36th day; the emergence rate of the April 5 sowing period reached 70% on the 27th day, and the emergence rate was stable (73.3%) on the 29th day. The "number of days from sowing to emergence rate reaching 70%" of the March 28 sowing period was recorded as 32 days, and that of the April 5 sowing period was 27 days.

[0050] III. Execution of the index calculation module Low-temperature emergence rate calculation: the actual number of seedlings was 32 at 70% emergence rate for the March 28 sowing period, and the low-temperature emergence rate was (32 / 50) x 100% = 64.0%; the actual number of seedlings was 34 at 70% emergence rate for the April 5 sowing period, and the low-temperature emergence rate was (34 / 50) x 100% = 68.0%; the average low-temperature emergence rate of the two sowing periods was 66.0%.

[0051] Emergence index calculation: total emergence number of 34 plants (maximum emergence rate 68.0%) on March 28, product sum 935.5, emergence index = 935.5 / 34 ≈ 27.5; total emergence number of 37 plants on April 5, product sum 812.3, emergence index = 812.3 / 37 ≈ 21.9.

[0052] Development starting temperature calculation: based on the data of each sowing period, the accumulated temperature model is fitted, the equation is Y=99.47 / (X-8.4), R²=0.96, P=0.003, and the development starting temperature b=8.4℃ is extracted.

[0053] Four, quantitative evaluation module execution Index weight and score: Development starting temperature (8.4℃): in line with ">8.0℃" interval, 19 points (weight 40%); Low temperature emergence rate (average 66.0%): in line with "≤68%" interval, 22 points (weight 35%); Emergence index (3 / 28 27.5): in line with "≥27.1" interval, 16 points (weight 25%).

[0054] Comprehensive grade: total score = 19+22+16=57 points, corresponding to "weak" level, it is suggested to sow in late April (ground temperature ≥17℃) in northern spring maize area, and the sowing depth should be strictly controlled at 0.05m.

[0055] Five, data verification module execution The emergence rates of non-low temperature sowing on April 15, April 25 and May 5 are 86.7%, 91.3% and 98.0% respectively, all ≥86%, confirming that the seeds have no potential germination defects, and the evaluation results are valid.

[0056] Summary One, consistency of core objectives and test basis of examples Both examples aim to "verify the discrimination of the evaluation system for different low temperature emergence ability varieties", strictly follow the module specifications of claims 1-9, and ensure the uniformity of the test basis conditions: Seed selection: the indoor sand culture germination rates of both varieties are ≥95% (Xiuqing 73-1 average 96.7%, Changcheng 799 average 95.3%), excluding seed quality interference, meeting the "qualified variety" standard; Test environment: The same standardized test field (elevation 310.5 m, light leached brown soil, previous crop soybean), uniform pre-treatment parameters such as plowing, watering, and pressing (e.g., 0-10 cm soil bulk density 1.25 g / cm³), 5 sowing periods (3.28-5.05, interval 10 days), uniform fertilization, and insect control measures, 0.1 m soil moisture content in each sowing period was 18.5%, to eliminate the influence of environmental and operational differences on the evaluation results.

[0057] II. Comparison of key module execution results (highlighting variety differences) Through comparison of data in each module, the significant difference in low temperature emergence ability between the two varieties is clearly shown, and the effectiveness of the system is verified.

[0058] III. Verification conclusion of the examples System effectiveness: In both examples, the evaluation system accurately distinguifies "extremely strong" and "weak" varieties through the whole process of "test basis - data collection - index calculation - quantitative evaluation - data verification", the matching degree of core indicators (development starting temperature, low temperature emergence rate) and comprehensive grade is 100%, which proves that the system can objectively reflect the low temperature emergence ability of varieties. Operation feasibility: The execution process of each module is clear (e.g., 3-point timing for soil temperature monitoring, and repeated investigation markers), and the parameters are quantifiable (e.g., sowing depth 0.05 m, and pressing wheel weight 80 kg), without the need for complex equipment, which meets the actual operation scenario in the field. Production guidance: Based on the sowing period recommendations based on the evaluation results (Xiuqing 73-1 can be sown early in late March, and Changcheng 799 needs to be sown late in late April), it directly meets the production needs of "early sowing and equal soil" in the northern spring maize area, and provides scientific basis for variety selection and cultivation management.

[0059] IV. System application value Through the implementation verification of two typical varieties, this evaluation system can be widely used for standardized evaluation of low temperature emergence ability of maize varieties in the northern spring maize area, solving the production pain points of "difficulty in quantifying variety cold tolerance and lack of basis for sowing period selection", and providing a reproducible evaluation tool for maize cold tolerance breeding, with practicality and scientific value.

[0060] The above shows and describes the basic principles, main features and advantages of the present application. Those skilled in the art should understand that the present application is not limited to the above-mentioned embodiments, and the above-mentioned embodiments and descriptions in the specification are only preferred examples of the present application and are not intended to limit the present application. Various changes and improvements can be made to the present application without departing from the spirit and scope of the present application, and these changes and improvements all fall within the scope of the claimed present application. The scope of protection of the present application is defined by the appended claims and their equivalents.

Claims

1. A corn variety low temperature emergence ability evaluation system, comprising a test base module, a data acquisition module, an index calculation module and a quantitative evaluation module, characterized in that: The modules are cooperated to realize the standardized evaluation: The test foundation module is used for screening qualified varieties and constructing a standardized test environment, wherein the screening of qualified varieties is completed by indoor sand culture germination test, 3 repetitions are set for each variety, 100 seeds are set for each repetition, and the varieties with germination rate ≥ 95% are selected; The data acquisition module is used for obtaining ground temperature and emergence dynamic data, wherein the ground temperature monitoring is to measure the temperature of 0.1m soil layer in the test field at 8:00, 14:00 and 20:00 every day from 5 days before the first sowing, and the average ground temperature of the day is calculated; the emergence investigation is to count the number of seedlings of each treatment at 15:00 every day from 5 days after sowing, and the emergence criterion is the emergence of seedlings, until the emergence rate of each treatment reaches or approaches the indoor sand culture germination rate, and the number of days from sowing to the emergence rate of 70% of each treatment is recorded; The index calculation module is used for extracting the characteristic value of low-temperature emergence ability, including calculating the low-temperature emergence rate based on two low-temperature sowing periods of March 28 and April 5, and calculating according to the formula "low-temperature emergence rate = (actual number of seedlings when the emergence rate reaches 70% / sowing number) × 100%"; calculating the emergence index according to the formula "emergence index = ∑ (the number of seedlings on a certain day × days after sowing) / total number of seedlings"; based on the daily average ground temperature and the number of days when the emergence rate reaches 70% of each sowing period, the development starting temperature is fitted by using the accumulated temperature model Y = a / (X-b), wherein Y is the number of days when the emergence rate reaches 70%, X is the daily average ground temperature, b is the development starting temperature, and a is a constant, the abnormal data exceeding the average emergence days of the same variety and the same sowing period ± 30% are removed, the fitting equation with R²≥0.93 and P≤0.01 is selected, and the value b in the equation is extracted; The quantitative evaluation module is used for determining the grade of low-temperature emergence ability, and the index weight distribution is 40% for the development starting temperature, 35% for the low-temperature emergence rate, and 25% for the emergence index, after interval scoring, the comprehensive score ≥90 points is extremely strong, 75-89 points is strong, 60-74 points is medium, and <60 points is weak.

2. The system for evaluating the low temperature emergence ability of a corn variety according to claim 1, characterized in that: The seeds for the indoor sand culture germination test in the test base module need to be strictly selected, specifically including manually selecting seeds with grain fullness ≥ 90%, uniform color and no mechanical damage, removing empty and worm-eaten grains and abnormal grains, then soaking in 0.1% potassium permanganate solution for 10 minutes for surface disinfection, and then drying for use in the test; this selection process can effectively eliminate the interference of seed physical defects or bacterial state on the germination rate, ensure the initial germination ability of the varieties entering the field evaluation to be consistent, and provide a fair benchmark for the comparison of low-temperature emergence ability; the standardized test environment is a plot with an altitude of about 310.5m, soil type of light loamy eluvial brown soil, soil fertility of medium, and previous crop of soybean; the plot needs to be finely ploughed in autumn, irrigated once before freezing, and pressed once for soil conservation after the 5cm soil layer is frozen in the middle and late February of the next year; five sowing periods of March 28, April 5, April 15, April 25 and May 5 are set, with an interval of 10 days during sowing; random block arrangement is adopted, with 3 repetitions; 50 seeds of the selected varieties to be evaluated are sown for each treatment; the planting method is large and small ridges, with a large row spacing of 0.5m, a small row spacing of 0.3m, a grain spacing of 0.06m, and a sowing depth of 0.05m; after sowing, the soil is covered with 0.04m and compacted; diammonium phosphate 10kg / 667m² is applied as seed fertilizer at the time of sowing; insecticide is applied on the ground after sowing to control underground pests and seedling pests; the soil water content of 0.1m soil layer is measured on the day of sowing to ensure the consistency of soil water content in each sowing period.

3. The system for evaluating the low temperature emergence ability of a corn variety according to claim 1, characterized in that: In addition to meeting the basic conditions of altitude and soil type, the standardized test field of the test base module also needs to be finely pretreated: the ploughing depth in autumn is controlled at 20-25cm to ensure uniform soil looseness; the water before freezing needs to make the water content of 0-30cm soil layer reach 70%-80% of the field water holding capacity to avoid differences in soil moisture caused by winter drought; the pressing in the middle and late February of the next year uses stone rollers with a weight of 50kg / m, which are rolled twice in the same direction to control the bulk density of 0-10cm soil layer at 1.2-1.3g / cm³; these measures can ensure the uniformity of soil physical and chemical properties in the test field and reduce the interference of microenvironment differences in the plot on emergence.

4. The system for evaluating low temperature emergence ability of a corn variety according to claim 1, characterized in that: In order to ensure consistency in operation, strict standardized procedures need to be followed in the staged sowing of the test base module: the operators are trained uniformly before sowing to ensure that the furrow depth error is not more than ±0.5cm and the seed quantity per hole of the sowing device is stable at 1 grain; after completing the sowing of one sowing period, 3 repeated areas are randomly selected to measure the actual sowing depth and soil covering thickness with a ruler, and the deviation is adjusted immediately if it exceeds the standard value; after soil covering, the same type of pressing wheel (width 1.2m, weight 80kg) is used for pressing to ensure that the soil is in close contact with the seeds, avoid the emergence time deviation caused by operation differences, and ensure the comparability of each treatment under the same environmental conditions.

5. The system for evaluating low temperature emergence ability of a corn variety according to claim 1, wherein: The data acquisition module of ground temperature monitoring needs to meet the high precision requirements: using the digital thermometer calibrated by measurement (accuracy ±0.1℃, resolution 0.01℃), the monitoring point is located in the middle of two rows of crops in each repetition area, 15 cm away from the plant, the thermometer probe is vertically inserted into the 0.1 m soil layer, and the surrounding soil needs to be compacted to eliminate air gaps; each observation needs to be recorded after 30 seconds of stable reading, and the weather conditions (sunny, cloudy, rainy) and wind grade of the day are also marked; if the deviation of a certain observation value from the adjacent two observation values exceeds 2℃, it needs to be re-measured and the abnormal reason (such as direct sunlight, probe loosening, etc.) is recorded to ensure the accuracy of the ground temperature data and provide reliable input for the subsequent accumulated temperature model fitting.

6. The system for evaluating low temperature emergence ability of a corn variety according to claim 1, wherein: The data acquisition module of emergence investigation needs to perform standardized recording process: at 15:00 every day, the emerged seedlings are marked with white marker pen (the marking position is the base of the seedling, without damaging the plant) to avoid repeated counting; in addition to recording the emergence number, the growth status of the seedlings is also recorded, including whether there are abnormal conditions such as yellowing and deformation; the data is input in real time using a special electronic form, the fields include sowing period, repetition area, variety name, daily emergence number, cumulative emergence number and abnormal seedling number, and data backup is performed after daily investigation (also saved in Excel and PDF formats) to prevent data loss and provide complete and accurate original data for the calculation of low temperature emergence rate and emergence index.

7. The system for evaluating low temperature emergence ability of a corn variety according to claim 1, wherein: In the index calculation module, the processing of low temperature sowing period data anomalies needs to follow clear standards: anomalies caused by non-temperature factors include diseases and pests (single treatment incidence rate ≥20%), extreme weather (such as rainfall ≥50mm within 24 hours after sowing leading to water accumulation in the field), and human operation errors (such as sowing rows being trampled); after determining the anomaly, the time of occurrence, specific performance and impact range need to be recorded in detail, and confirmed by more than two test personnel; if only the March 28 sowing period is abnormal, the low temperature emergence rate is calculated using the April 5 sowing period data, and vice versa; if both sowing periods are abnormal, the low temperature sowing period test of the variety needs to be re-arranged to ensure that the low temperature emergence rate data used for evaluation can truly reflect the cold tolerance of the variety.

8. The system for evaluating low temperature emergence ability of a corn variety according to claim 1, wherein: The scoring interval division of the quantitative evaluation module is based on detailed test data support: the development starting temperature interval refers to the 95% confidence interval of 5 participating varieties (Xiuqing 73-1, Changcheng 306, Changcheng 218, Changcheng 799, Changcheng 802) for 3 years of repeated tests, among which the extremely strong interval (≤5.5℃) corresponds to the mean (5.12℃) of Xiuqing 73-1 plus or minus 0.38℃ error range, the strong interval (5.6-6.5℃) corresponds to the mean (6.05℃) of Changcheng 306 plus or minus 0.45℃, the moderate interval (6.6-8.0℃) corresponds to the mean (7.3℃) of Changcheng 218 plus or minus 0.7℃, and the weak interval (>8.0℃) corresponds to the lowest value of Changcheng 799 (8.40℃) and Changcheng 802 (8.20℃); the score uses linear interpolation method, the development starting temperature 5.3℃ corresponds to 38 points, and 6.2℃ corresponds to 32 points, to ensure that the scoring results can accurately reflect the cold tolerance difference between varieties.

9. The system for evaluating low temperature emergence ability of a corn variety according to claim 1, wherein: The data verification module also includes a core logic of verifying seed quality by using non-low temperature sowing performance: when the ground temperature of the three sowing periods is all greater than or equal to 17 DEG C, the difference in the emergence ability between varieties should be very small, at this time, if the emergence rate of the variety to be evaluated is all greater than or equal to 86%, it indicates that the seed has no potential germination defects, and the evaluation result is valid; if the emergence rate of any sowing period is less than 86%, it is necessary to re-perform the indoor sand culture germination test, if the bud rate is still greater than or equal to 95%, the field environmental factors are checked, and if necessary, the test field is replaced to re-develop the evaluation.

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