Method for evaluating lodging-resistant character of rice and application of method

Abstract

The invention provides a method for evaluating the lodging-resistant character of rice and application of the method, and belongs to the technical field of rice planting. According to the method for evaluating the lodging-resistant character of the rice, natural stress is simulated on the basis of the engineering bionics principle, accurate and efficient stress treatment and data collection are achieved by establishing a standardized testing system with high controllability, and the method has the advantages of being high in representativeness and practicability, capable of achieving nondestructive testing, diversified in application and the like. According to the method, a specific fixing device is not needed, the evaluation cost is low, the identification scale is larger and basically not limited, and the evaluation efficiency is higher; the rice lodging state is closer to the natural rice lodging state in field identification. According to the technology, effective connection from basic research to production practice is achieved through a standardized path, and the problems that a traditional rice lodging resistance testing method is low in efficiency, high in cost and insufficient in precision are solved.

Description

Technical Field

[0001] The present invention belongs to the technical field of rice cultivation, and particularly relates to a method for evaluating the lodging resistance traits of rice and its application. Background Art

[0002] Rice lodging is a phenomenon in which the stem of rice skews or even the whole plant lies prostrate on the ground under the interaction of external factors such as wind, rain, terrain, soil environment, tillage measures and internal factors such as the lodging resistance of the plant itself during the growth process of rice. The interaction of cultivation conditions, climate environment and variety characteristics is the main cause of rice lodging. Under natural conditions, severe lodging caused by wind, rain, etc. can reduce the rice yield by 50%. In addition to causing yield loss of rice, lodging can also cause a significant decline in quality. The humidity in the lodged crop community increases significantly, which is conducive to the growth of fungi and induces diseases, having an adverse impact on the appearance quality and internal quality of grains. Plant lodging can also cause a large number of ear buds, directly leading to a decline in quality, and the impact on varieties with weak seed dormancy characteristics is more serious. In addition, lodging can also cause difficulties in operations such as harvesting, thus significantly reducing the harvesting efficiency and increasing the harvesting cost. Lodging has become one of the main factors affecting the mechanized and large-scale production of rice, resulting in yield loss and quality decline of rice, and restricting the further development of rice production. Therefore, the lodging resistance characteristics of rice varieties and the cultivation regulation technology for improving the lodging resistance ability of varieties are of great significance for the high-yield, high-efficiency and high-quality production of rice.

[0003] However, due to the fact that the current traditional methods for testing the lodging resistance ability of rice mainly rely on natural wind fields or artificial simulation of wind power (such as fan arrays), there are still many deficiencies in the following aspects, which are not conducive to the efficient breeding of lodging-resistant varieties and the rapid optimization of cultivation techniques. For example, low efficiency: the natural wind field is uncontrollable, and it is necessary to wait for a long time for specific wind conditions; the cost of artificial simulation equipment is high and the coverage range is limited; poor accuracy: it is impossible to accurately control the wind speed, wind direction and wind field uniformity, resulting in poor repeatability of test results; complex operation: it is difficult to achieve large-scale and multi-repeated rapid tests in the field with existing methods; destructive sampling test: on the one hand, it cannot comprehensively reflect the actual lodging resistance ability under complex field environments, and on the other hand, it is not conducive to the evaluation and screening of low-generation rice breeding materials or resources, that is, the amount of seeds is small, and each individual is very precious. After the destructive sampling inspection, seeds cannot be obtained again.

[0004] Therefore, there is an urgent need for a test and evaluation technology system with strong controllability, standardization, precision and high efficiency to solve the above deficiencies of traditional methods and promote the high-quality and efficient development of the rice industry. Summary of the Invention

[0005] Aiming at the defects in the prior art, the purpose of the present invention is to provide a method for evaluating the lodging resistance traits of rice. Through the creation of a specific wind field and the construction of an evaluation index system, this method can accurately and efficiently measure the lodging resistance properties of rice, with the advantage of strong controllability.

[0006] The purpose of the present invention is achieved through the following technical solutions:

[0007] The present invention provides a method for evaluating the lodging resistance traits of rice, including:

[0008] Flying a flight instrument above the target detection rice to apply a wind field; the wind field forms a wind speed of 8.0 - 11.0 m / s in the rice canopy; the flight instrument flies back and forth 2 - 3 times above the target detection rice to apply the wind field, so that the wind force covers the target detection rice area;

[0009] After applying the wind field, measure the tilting angle of the rice, and divide it into 5 tilting intervals according to the tilting angle, which are the plant tilting angle α ≤ 10°, 10° < α ≤ 30°, 30° < α ≤ 45°, 45° < α ≤ 60° and α > 60°;

[0010] Calculate the lodging rate in each tilting interval; the lodging rate in each tilting interval is the ratio of the lodging area in each tilting interval to the total area of the target detection rice area; or, the ratio of the lodging plants in each tilting interval to the total number of plants in the target detection rice area;

[0011] Calculate the lodging degree in each tilting interval through lodging degree = lodging rate × tilting angle weight; the tilting angle weight value corresponding to the tilting interval α ≤ 10° is 0, the tilting angle weight value corresponding to 10° < α ≤ 30° is 1, the tilting angle weight value corresponding to 30° < α ≤ 45° is 2, the tilting angle weight value corresponding to 45° < α ≤ 60° is 3, and the tilting angle weight value corresponding to α > 60° is 4;

[0012] Obtain the overall lodging degree by calculating the sum of the lodging degrees in each tilting interval; the overall lodging degree is negatively correlated with the lodging resistance traits of rice.

[0013] Preferably, the periods for applying the wind field to the rice include the late milk - ripe stage and / or the yellow - ripe stage and any period between them.

[0014] Preferably, the flight instrument is perpendicular to the rice planting row direction during flight.

[0015] Preferably, the flight instrument flies at a constant speed along the central flight path of the target detection rice area during flight.

[0016] Preferably, the flight instrument includes a multi - rotor unmanned aerial vehicle.

[0017] Preferably, the flight speed of the flying instrument is 2 - 3 m / s; the flight height of the flying instrument is 1.0 - 2.0 m from the rice canopy.

[0018] Preferably, within 0.5 - 4 h after the wind field is applied to the rice, the tilting angle of the rice in the target detection area is measured.

[0019] Preferably, 0.0 ≤ overall lodging degree < 0.8, the rice has a strong lodging resistance level; 0.8 ≤ overall lodging degree < 1.6, the rice has a relatively strong lodging resistance level; 1.6 ≤ overall lodging degree < 2.4, the rice has a medium lodging resistance level; 2.4 ≤ overall lodging degree < 3.2, the rice has a poor lodging resistance level; 3.2 ≤ overall lodging degree < 4.0, the rice has a very poor lodging resistance level.

[0020] The present invention provides the application of the method described in the above technical solution in screening rice germplasm resources with lodging resistance.

[0021] The present invention provides the application of the method described in the above technical solution in regulating rice cultivation patterns and / or regulating rice quality.

[0022] Advantages of the present invention:

[0023] The present invention provides a method for evaluating the lodging resistance traits of rice, including: flying a flying instrument above the target detection rice to apply a wind field to the rice; the wind field forms a wind speed of 8.0 - 11.0 m / s at the rice canopy; the flying instrument flies back and forth 2 - 3 times above the target detection rice to apply the wind field, so that the wind force covers the target detection rice area; after the application of the wind field is completed, the tilting angle of the rice is measured, and it is divided into 5 tilting intervals according to the tilting angle, namely the plant tilting angle α ≤ 10°, 10° < α ≤ 30°, 30° < α ≤ 45°, 45° < α ≤ 60° and α > 60°; calculate the lodging rate in each tilting interval; the lodging rate in each tilting interval is the ratio of the lodging area in each tilting interval to the total area of the target detection rice area; or, the ratio of the lodging plants in each tilting interval to the total number of plants in the target detection rice area; calculate the lodging degree in each tilting interval through lodging degree = lodging rate × tilting angle weight; the tilting angle weight value corresponding to the tilting interval α ≤ 10° is 0, the tilting angle weight value corresponding to 10° < α ≤ 30° is 1, the tilting angle weight value corresponding to 30° < α ≤ 45° is 2, the tilting angle weight value corresponding to 45° < α ≤ 60° is 3, and the tilting angle weight value corresponding to α > 60° is 4; calculate the sum of the lodging degrees in each tilting interval to obtain the overall lodging degree; the overall lodging degree is negatively correlated with the lodging resistance traits of rice.

[0024] The method described in the present invention simulates natural stress based on the principle of engineering bionics. By establishing a highly controllable standardized test system, through the manufacture of a specific wind field and the construction of an evaluation index system, precise and efficient stress treatment and data collection are achieved. The representative of the rice lodging resistance ability measured by the method is strong, closer to the actual natural lodging situation, can relatively better comprehensively reflect the actual lodging resistance ability under the complex field environment, can accurately and efficiently measure the lodging resistance properties of rice, and has the advantage of strong controllability.

[0025] Furthermore, the method has strong practicability: the equipment is simple, the operation is convenient, and the cost is controllable, which is suitable for large-scale field applications; the method can achieve non-destructive testing: it can evaluate the lodging resistance characteristics of rice varieties with high throughput, without destructive sampling, and is very suitable for the large-scale evaluation and screening of low-generation breeding materials, significantly improving the breeding efficiency; the method has multiple applications: it can not only screen lodging-resistant germplasm resources, but also verify the actual effects of different cultivation modes (close planting / fertilization) and regulation products, providing a quantitative basis for stress resistance research and cultivation technology optimization. The method described in the present invention does not require a specific fixing device, has a low evaluation cost, a larger and basically unrestricted identification scale, and a higher evaluation efficiency; the field identification is closer to the natural lodging state of rice. This technology realizes the effective connection from basic research to production practice through a standardized path, solving the problems of low efficiency, high cost, and insufficient accuracy of traditional rice lodging resistance testing methods.

[0026] Furthermore, in the method for evaluating the lodging resistance traits of rice in the present invention, a wind field for lodging treatment can be created by using an unmanned aerial vehicle, making up for the deficiencies of existing methods that rely on natural wind fields or artificial simulation of wind power, etc. The corresponding method provided by the present invention has the advantages of high efficiency, good accuracy and repeatability. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0028] Figure 1 During the process of evaluating the lodging resistance traits of rice, it is the round-trip flight path diagram of the unmanned aerial vehicle;

[0029] Figure 2 During the process of evaluating the lodging resistance traits of rice, it is the path diagram of the round-trip movement of the circular unmanned aerial vehicle wind field to evenly cover the test area. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0030] The present invention provides a method for evaluating the lodging resistance traits of rice, including:

[0031] Fly a flight instrument above the target detection rice to apply a wind field to the rice; the wind field forms a wind speed of 8.0 - 11.0 m / s in the rice canopy; the flight instrument flies back and forth 2 - 3 times above the target detection rice to apply the wind field, so that the wind force covers the target detection rice area;

[0032] After the application of the wind field is completed, measure the tilting angle of the rice, and divide it into 5 tilting intervals according to the tilting angle, which are the plant tilting angle α ≤ 10°, 10° < α ≤ 30°, 30° < α ≤ 45°, 45° < α ≤ 60° and α > 60°;

[0033] Calculate the lodging rate in each tilting interval; the lodging rate in each tilting interval is the ratio of the lodging area in each tilting interval to the total area of the target detection rice area; or, the ratio of the lodging plants in each tilting interval to the total number of plants in the target detection rice area;

[0034] Calculate the lodging degree in each tilting interval through lodging degree = lodging rate × tilting angle weight; the tilting angle weight value corresponding to the tilting interval α ≤ 10° is 0, the tilting angle weight value corresponding to 10° < α ≤ 30° is 1, the tilting angle weight value corresponding to 30° < α ≤ 45° is 2, the tilting angle weight value corresponding to 45° < α ≤ 60° is 3, and the tilting angle weight value corresponding to α > 60° is 4;

[0035] Obtain the overall lodging degree by calculating the sum of the lodging degrees in each tilting interval; the overall lodging degree is negatively correlated with the lodging resistance trait of the rice.

[0036] The method provided by the present invention can directly evaluate the lodging resistance of different rice varieties in the already planted area; it can also directly detect the lodging resistance of the rice after planting a specific variety of rice. As an optional implementation manner of the present invention, when using the method to evaluate the lodging resistance of different varieties of rice, the cultivation and planting method of the rice adopts a consistent manner. As an optional implementation manner of the present invention, when measuring the lodging resistance of a certain variety of rice and / or multiple different varieties of rice, a rice variety with known lodging resistance can be set as a control or reference.

[0037] In the present invention, there is no special limitation on the cultivation method of the rice, and any conventional rice cultivation method in the art can be adopted. That is, the method provided by the present invention can be used to evaluate the lodging resistance of rice in different rice cultivation methods. When the method provided by the present invention is used to evaluate the lodging resistance of a certain rice variety and / or multiple rice varieties, rice varieties with known lodging resistance can be set as controls and / or references. When the method provided by the present invention is used to evaluate the lodging resistance of multiple rice varieties, the cultivation methods of the multiple rice varieties are preferably the same; the cultivation methods include agronomic measures such as planting density and / or fertilization methods.

[0038] As an optional embodiment of the present invention, the method evaluates the lodging resistance traits at the late milk-ripe stage and / or the yellow-ripe stage of the rice and any stage in between. That is to say, the period when the wind field is applied to the rice includes the late milk-ripe stage and / or the yellow-ripe stage and any stage in between; any stage in between includes the dough-ripe stage. The method provided by the present invention can be carried out at any stage from the start of the late milk-ripe stage to the end of the yellow-ripe stage of the rice. When the method of the present invention is used to detect different rice varieties, based on the fact that the growth stages of different rice varieties may not be very consistent, different rice varieties may be in different growth periods on the day of detection. The method of the present invention can be carried out when the different rice varieties to be detected are at the late milk-ripe stage and / or the yellow-ripe stage and any stage in between, that is, the method of the present invention can be carried out at any stage of the late milk-ripe stage, dough-ripe stage, and yellow-ripe stage of the different rice varieties to be detected. For example, when some rice varieties are at the late milk-ripe stage and some other rice varieties are at the dough-ripe stage, the method of the present invention can be used to evaluate the lodging resistance traits of the rice; or when some rice varieties are at the late milk-ripe stage and some other rice varieties are at the yellow-ripe stage, the method of the present invention can be used to evaluate the lodging resistance traits of the rice; or when some rice varieties are at the dough-ripe stage and some other rice varieties are at the yellow-ripe stage, the method of the present invention can be used to evaluate the lodging resistance traits of the rice; or when some rice varieties are at the late milk-ripe stage, some other rice varieties are at the dough-ripe stage, and some other rice varieties are at the yellow-ripe stage, the method of the present invention can be used to evaluate the lodging resistance traits of the rice. The reason for detecting the lodging resistance traits of the rice at this stage in the present invention is mainly based on the fact that the rice is most likely to lodge or the probability of lodging is relatively high during this period in production practice. As an optional embodiment of the present invention, the late milk-ripe stage includes that more than 80% of the grains in the middle of the rice panicles are filled with the husks; the content is a milky slurry content. As an optional embodiment of the present invention, the yellow-ripe stage refers to the period when more than 80% of the glumes of the early rice turn yellow and more than 90% of the glumes of the middle and late rice turn yellow.

[0039] The present invention involves flying a flight instrument above the target - detected rice to apply a wind field to the rice; the wind field forms a wind speed of 8.0 - 11.0 m / s in the rice canopy. As an alternative embodiment of the present invention, the wind speed formed by the wind field in the rice canopy can be 8.0, 8.5, 9.0, 9.5, 10.0, 10.5, 10.6, 10.7, 10.8, 10.9, or 11.0 m / s. In the method for evaluating the lodging - resistance trait of rice in the present invention, by measuring under the wind - field condition of 8.0 - 11.0 m / s, the lodging - resistance ability of rice can be better reflected; if the wind speed is less than 8.0 m / s, the rice will not lodge or the lodging probability will be relatively low, and if it is greater than 11.0 m / s, most varieties will lodge, thus failing to achieve the effect of screening out varieties with excellent lodging - resistance performance.

[0040] As an alternative embodiment of the present invention, the flight instrument includes a drone; the drone can be a multi - rotor unmanned aircraft; the drone can be a DJI T60, a DJI T25P drone, or a drone that can generate a wind field with the same wind speed. As an alternative embodiment of the present invention, the flight instrument can fly at a height of 1.0 - 2.0 m above the rice canopy to apply a wind field to the target - detected rice; the height can be 1.0, 1.5, or 2.0 m. In the present invention, when the flight instrument flies, it preferably flies perpendicular to the rice transplanting row direction; the flight preferably flies along the central route of the target - detected rice area, and more preferably flies uniformly along the central route of the target - detected rice area. As an alternative embodiment of the present invention, the flight instrument adopts an automatic flight mode during the formation of the wind field; the flight speed of the flight instrument can be 2 - 3 m / s, or can also be 2, 2.5, or 3 m / s.

[0041] As an alternative embodiment of the present invention, during the process of applying the wind field, the flight instrument flies back and forth above the target - detected rice 2 - 3 times to apply the wind field, or can also be 2 or 3 times; during the flight process, the flight instrument ensures that the width of the wind field matches the width of the target - detected rice area, and the wind force evenly covers the target area. As an alternative embodiment of the present invention, the matching of the width of the wind field with the width of the target - detected rice area means that the width of the wind field ≥ the width of the target - detected rice area. As an alternative embodiment of the present invention, the width of the target - detected rice area can be 1.5 - 3 m, or can also be 1.5, 2.0, 2.5, or 3.0 m. The present invention has no special limitation on the length of the target - detected rice area, and it can be any length > 0. In the embodiment, a test plot with a length of 15 m is taken as an example to specifically illustrate the method for evaluating the lodging - resistance trait of rice provided by the present invention.

[0042] After applying a wind field to the rice in the target detection area of the present invention, the tilting angle of the rice is measured. As an alternative embodiment of the present invention, within 0.5 to 4 hours after the application of the wind field to the rice is completed, the tilting angle measurement of the rice in the target detection area is completed. After completing the measurement of the tilting angle of the rice, the present invention preferably calculates the lodging degree of the rice based on the tilting angle of the rice, and then obtains the overall lodging degree of the rice, and evaluates the lodging resistance trait of the rice through the overall lodging degree of the rice. In the present invention, the overall lodging degree is negatively correlated with the lodging resistance trait of the rice.

[0043] After obtaining the tilting angle of the rice, the present invention preferably divides a certain rice variety to be tested in the target detection rice area into 5 tilting intervals according to the tilting angle, namely, the tilting interval where the plant tilting angle α ≤ 10°, the tilting interval where the tilting angle 10° < α ≤ 30°, the tilting interval where the tilting angle 30° < α ≤ 45°, the tilting interval where the tilting angle 45° < α ≤ 60°, and the tilting interval where the tilting angle α > 60°; the 5 tilting intervals can also be simply referred to as the plant tilting angle α ≤ 10°, 10° < α ≤ 30°, 30° < α ≤ 45°, 45° < α ≤ 60°, and α > 60°.

[0044] After determining each tilting interval in the target detection rice area, the present invention preferably calculates the lodging rate in each tilting interval. In the present invention, the lodging rate in each tilting interval is the ratio of the lodging area in each tilting interval to the total area of the target detection rice area; or, the ratio of the lodging plants in each tilting interval to the total number of plants in the target detection rice area.

[0045] After determining the lodging rate in each tilting interval of the rice to be tested, the lodging degree in each tilting interval is calculated through the lodging rate. The present invention calculates the lodging degree in each tilting interval through lodging degree = lodging rate × tilting angle weight; the tilting angle weight value corresponding to α ≤ 10° in the tilting interval is 0; the tilting angle weight value corresponding to 10° < α ≤ 30° is 1; the tilting angle weight value corresponding to 30° < α ≤ 45° is 2; the tilting angle weight value corresponding to 45° < α ≤ 60° is 3; the tilting angle weight value corresponding to α > 60° is 4.

[0046] After obtaining the lodging degree in each tilting interval, the overall lodging degree is obtained by calculating the sum of the lodging degrees in each tilting interval; the overall lodging degree is negatively correlated with the lodging resistance trait of the rice. As an alternative embodiment of the present invention, 0.0 ≤ overall lodging degree < 0.8, the lodging resistance ability level of the rice is strong; 0.8 ≤ overall lodging degree < 1.6, the lodging resistance ability level of the rice is relatively strong; 1.6 ≤ overall lodging degree < 2.4, the lodging resistance ability level of the rice is medium; 2.4 ≤ overall lodging degree < 3.2, the lodging resistance ability level of the rice is poor; 3.2 ≤ lodging resistance ability level of the rice is poor < 4.0, the lodging resistance ability level of the rice is very poor.

[0047] The existing methods for evaluating the lodging resistance traits of rice mainly include: lodging grade method, stem breaking moment method, stem elasticity method, lodging index method, etc. The traditional testing methods for the lodging resistance of rice mainly rely on natural wind fields or artificial simulation of wind forces (such as fan arrays), and have the following deficiencies: (1) Low efficiency: The natural wind field is uncontrollable, and long waiting times are required for specific wind force conditions; the cost of artificial simulation equipment is high and the coverage is limited; (2) Poor accuracy: It is impossible to accurately control the wind speed, wind direction and wind field uniformity, resulting in poor repeatability of test results; (3) Complicated operation: It is difficult to achieve rapid testing on a large scale and with multiple repetitions in the field using existing methods.

[0048] Compared with the existing "lodging grade method", the method provided by the present invention has more objective, quantitative and accurate data, is less affected by human factors, has higher efficiency and good repeatability.

[0049] Compared with the existing "stem breaking moment method" and "stem elasticity method", the method provided by the present invention does not require destructive sampling, can be carried out in real time in the field, and can relatively better comprehensively reflect the actual lodging resistance in the complex field environment.

[0050] Compared with the existing "lodging index method", the method provided by the present invention does not require a large amount of data support and model verification, has a lower computational complexity, and the equipment and method are simpler and more operable.

[0051] Compared with the randomness of evaluating the lodging characteristics of rice under natural wind and rain conditions, the method provided by the present invention is more accurate and controllable, and can reproduce standardized test conditions.

[0052] Compared with "CN108241786A - A method for evaluating the lodging resistance of rice" and "CN115683819A - A device for measuring the lodging resistance of rice in the field", the method provided by the present invention does not require specific fixing devices, has a low evaluation cost, a larger and basically unrestricted evaluation scale, and higher evaluation efficiency; the field identification is closer to the natural lodging state of rice, and the results are more representative.

[0053] The present invention provides an application of the method described in the above technical solution in screening rice germplasm resources with lodging resistance. The method provided by the present invention can screen out rice germplasm resources with lodging resistance by evaluating the lodging resistance traits of rice.

[0054] The present invention provides the application of the method described in the above technical solution in the regulation of rice cultivation patterns and / or the regulation of rice quality. As an optional implementation manner of the present invention, the cultivation pattern includes the cultivation density of rice and / or the fertilization method of rice. For example, the method of the present invention can be used to verify different cultivation densities of the same kind of rice. If the lodging resistance of the rice is stronger after detection by the method of the present invention under the corresponding cultivation density, then the corresponding cultivation density can be used as the cultivation density for high-efficiency rice yield increase. Or, the method of the present invention can be used to verify different fertilization methods of the same kind of rice. If the lodging resistance of the rice is stronger after detection by the method of the present invention under the corresponding fertilization method, then the corresponding fertilization method can be used as the fertilization method for high-efficiency rice yield increase. The method provided by the present invention can also regulate the quality of rice. By screening lodging-resistant rice varieties and the most suitable cultivation pattern for a certain rice through the method of the present invention, it is beneficial to improve the quality of rice and achieve the effect of regulating the quality of rice.

[0055] The method provided by the present invention can not only screen lodging-resistant germplasm resources, but also verify the actual effects of different cultivation patterns (close planting / fertilization) and regulate the quality of rice, providing a quantitative basis for stress resistance research and cultivation technology optimization, and thus being beneficial to better regulating the quality of rice. This technology realizes the effective connection from basic research to production practice through a standardized path, solving the problems of low efficiency, high cost, and insufficient accuracy of traditional rice lodging resistance testing methods.

[0056] To further illustrate the present invention, the technical effects provided by the present invention will be described in detail below in conjunction with the drawings and embodiments, but they should not be construed as limiting the protection scope of the present invention.

[0057] Example 1

[0058] A method for evaluating the lodging resistance traits of rice is as follows:

[0059] 1. UAV wind field pressurized stress treatment

[0060] UAV selection and parameter setting: Select a general multi-rotor agricultural UAV for rice production, such as DJI T60 or DJI T25P, and use the automatic flight mode to fly at a constant speed; set the flight height 1.0 - 2.0 meters above the rice canopy and the flight speed 2 - 3 m / s to generate a 5-level strong wind standard, that is, a wind field with a wind speed of 8.0 - 11.0 m / s at the rice canopy.

[0061] Wind field control: Fly vertically along the center line of the test area perpendicular to the rice planting row direction, back and forth 2 - 3 times to ensure that the wind field width matches the test area width, that is, the test area width ≤ wind field width, and the wind force evenly covers the target area, as Figure 1 and Figure 2 shown.

[0062] 2. Evaluation of overall lodging degree

[0063] After all the varieties in the rice population to be evaluated enter the late milk-ripe stage, that is, at any stage between the late milk-ripe stage and the yellow-ripe stage of all the varieties in the rice population to be evaluated, a wind field is formed in the rice canopy above the rice population to be evaluated by using the method described in step 1.

[0064] Within 0.5 - 4.0 h after the UAV wind field treatment, using the overall lodging degree evaluation method, investigate the tilting angle and lodging rate of the rice population to be evaluated, then calculate the lodging degree and overall lodging degree by using the weights of the lodging rate and tilting angle, and finally evaluate the level of the lodging resistance characteristics of the variety by using the overall lodging degree value.

[0065] Grouping of the tilting situation of the population to be evaluated: Subdivide the tilting situation of the rice population within a single evaluation unit into 5 tilting intervals, that is, the plant tilting angle α ≤ 10°, 10° < α ≤ 30°, 30° < α ≤ 45°, 45° < α ≤ 60° and α > 60°.

[0066] Calculation of lodging ratio (LR): The lodging ratio of a certain tilting interval refers to the ratio of the lodging area to the total area of the experimental plot within a certain plant tilting angle interval; or the ratio of the lodging plants to the total number of plants in the experimental plot within a certain plant tilting angle interval; that is: The lodging ratio of a certain tilting interval = the lodging area within a certain plant tilting angle interval / the total area of the population × 100% = the number of lodging plants within a certain plant tilting angle interval / the total number of plants in the population × 100%.

[0067] Assignment of tilt angle weight (TAW): The tilt angle weight is a specific constant, which refers to the weight value assigned according to the influence of the rice plant tilting angle α on the severity of lodging, so as to reflect the actual threat of lodging to yield. The larger the plant tilting angle, the more serious the lodging and the greater the impact on yield. Therefore, a higher weight is assigned, so that the lodging ratio in this interval contributes more to the total lodging degree, thus more accurately reflecting the lodging resistance ability of the variety. The specific assignment is shown in Table 1.

[0068] Table 1 Assignment of the plant tilting angle α and its biological significance

[0069]

[0070]

[0071] Calculation of lodging degree (LD): The lodging degree of a certain tilting interval refers to the product of the lodging ratio and the weight of a certain tilting interval, that is: The lodging degree of a certain tilting interval = the lodging ratio of a certain tilting interval × tilt angle weight.

[0072] Calculation of Overall Lodging Degree (OLD): The overall lodging degree refers to the overall inclination or lodging degree of all plants within the evaluated population, which is the sum of the lodging degrees in 5 inclination intervals. The larger the OLD value, the worse the lodging resistance of the variety. The specific calculation formula and value requirements are as follows:

[0073] OLD = LR1×0 + LR2×1 + LR3×2 + LR4×3 + LR5×4, 0.0 ≤ OLD ≤ 4.0, and the value is retained to one decimal place.

[0074] LR1: The ratio of the number of plants with inclination angle α ≤ 10° to the total number of plants in the population, or the ratio of the area with inclination angle α ≤ 10° to the total area of the population;

[0075] LR2: The ratio of the number of plants with inclination angle 10° < α ≤ 30° to the total number of plants in the population, or the ratio of the area with inclination angle 10° < α ≤ 30° to the total area of the population;

[0076] LR3: The ratio of the number of plants with inclination angle 30° < α ≤ 45° to the total number of plants in the population, or the ratio of the area with inclination angle 30° < α ≤ 45° to the total area of the population;

[0077] LR4: The ratio of the number of plants with inclination angle 45° < α ≤ 60° to the total number of plants in the population, or the ratio of the area with inclination angle 45° < α ≤ 60° to the total area of the population;

[0078] LR5: The ratio of the number of plants with inclination angle 60° < α to the total number of plants in the population, or the ratio of the area with inclination angle 60° < α to the total area of the population.

[0079] Evaluate the lodging resistance characteristic level of the variety according to the OLD value, as shown in Table 2.

[0080] Table 2 Evaluation of the lodging resistance characteristic level of the variety by OLD value

[0081] Range of OLD values for overall lodging degree Level of lodging resistance of the variety 0.0 ≤ OLD < 0.8 Strong 0.8 ≤ OLD < 1.6 Relatively strong 1.6 ≤ OLD < 2.4 Medium 2.4 ≤ OLD < 3.2 Relatively poor 3.2 ≤ OLD < 4.0 Poor

[0082] The OLD value can be directly used to evaluate the lodging resistance ability of the variety, and can also be used for horizontal comparison of the lodging resistance abilities of different varieties.

[0083] Application Example 1

[0084] Test location: Experimental base in Guotian Village, Longmen Town, Lukou District, Zhuzhou City.

[0085] Width of the test area: 2m; Length of the test area: 15m; 5 rows of protective rows are set around the test area.

[0086] Selected UAV type: DJI T60.

[0087] The test area was randomly divided into 15 plots, and Nongxiang 42, Taiyou Nong 39, Tianyou Huazhan (Tianyou Huazhan was used as the control variety, which had strong lodging resistance in large-scale production applications and multi-year multi-point tests), Y Liangyou 911, and Yexiangyou Lisi were planted respectively. Each plot was planted with one rice variety, and different rice varieties were planted adjacent to each other directly without empty rows. Each rice variety was subjected to 3 parallel tests, with 50 plants in each parallel test arranged in 5 rows, with 10 plants in each row. The plant spacing and row spacing for rice planting were 20 cm × 20 cm.

[0088] Due to the difference in growth periods among varieties, when all varieties were in the late milk-ripe stage to the yellow-ripe stage (that is, at any stage between the late milk-ripe stage or the yellow-ripe stage or from the late milk-ripe stage to the yellow-ripe stage), the lodging resistance evaluation method of Example 1 was used to detect the lodging resistance of each variety.

[0089] The specific method was as follows:

[0090] The drone adopted an automatic flight mode and flew at a constant speed. The set flight height was 1.5 m from the rice canopy, and the flight speed was 2.5 m / s, forming a wind field of 8.0 - 11.0 m / s above the rice canopy, that is, the standard of strong wind at level 5.

[0091] During the flight of the drone, it was perpendicular to the rice planting row direction and flew at a constant speed along the central flight path of the test area, making 3 round trips. The flight time for the drone to make 1 round trip was about 15 seconds, ensuring that the width of the wind field matched the test area and the wind force evenly covered the target area.

[0092] Within 0.5 - 4.0 hours after the drone wind field treatment, the overall lodging degree evaluation method was used to complete the lodging degree investigation and lodging resistance trait evaluation.

[0093] The lodging resistance of each variety was evaluated using the above method. The specific investigation data (average value of 3 replicates) of Tianyou Huazhan, Nongxiang 42, Yexiangyou Lisi, Taiyou Nong 39, and Y Liangyou 911 are as follows.

[0094] The test results of the evaluation indexes of the lodging resistance of each variety of rice using the above method are shown in Table 3.

[0095] Table 3 Test results of the evaluation indexes of the lodging resistance of each variety of rice (average value of 3 parallel tests)

[0096]

[0097]

[0098] The overall lodging degree OLD of Tianyou Huazhan = (8% × 4 + 16% × 3 + 22% × 2 + 30% × 1 + 24% × 0) = 1.5;

[0099] For Nongxiang 42, OLD = (15% × 4 + 20% × 3 + 25% × 2 + 30% × 1 + 10% × 0) = 2.0;

[0100] For Yexiang Youlis, OLD = (24% × 4 + 32% × 3 + 22% × 2 + 16% × 1 + 6% × 0) = 2.5;

[0101] For Taiyou Nong 39, OLD = (26% × 4 + 30% × 3 + 24% × 2 + 10% × 1 + 10% × 0) = 2.5;

[0102] For Y Liangyou 911, OLD = (0 × 4 + 0 × 3 + 10% × 2 + 14% × 1 + 76% × 0) = 0.3.

[0103] Judging according to the evaluation criteria provided by the present invention: Y Liangyou 911 has strong lodging resistance, Tianyou Huazhan has relatively strong lodging resistance, Nongxiang 42 has medium lodging resistance, and Yexiang Youlis and Taiyou Nong 39 have relatively poor lodging resistance. The results of evaluating the lodging resistance of the above 5 varieties by using the method for evaluating the lodging resistance traits of rice of the present invention are consistent with the large-area production experience of the corresponding varieties.

[0104] Application Example 2

[0105] The specific method is the same as that of Application Example 1, and the only difference is that the evaluation and detection results of the lodging resistance of each test variety are as shown in Table 4 below when the wind field formed by the unmanned aerial vehicle in the rice canopy is 6.0 - 7.5 m / s.

[0106] Table 4 Detection results of the evaluation indexes of the lodging resistance of each variety of rice (wind speed 6.0 - 7.5 m / s)

[0107]

[0108] For Tianyou Huazhan, the overall lodging degree OLD = (0% × 4 + 0% × 3 + 4% × 2 + 8% × 1 + 88% × 0) = 0.2;

[0109] For Nongxiang 42, OLD = (0% × 4 + 0% × 3 + 12% × 2 + 6% × 1 + 82% × 0) = 0.3;

[0110] For Yexiang Youlis, OLD = (0% × 4 + 6% × 3 + 10% × 2 + 28% × 1 + 56% × 0) = 0.7;

[0111] For Taiyou Nong 39, OLD = (0% × 4 + 4% × 3 + 16% × 2 + 32% × 1 + 48% × 0) = 0.8;

[0112] For Y Liangyou 911, OLD = (0 × 4 + 0 × 3 + 0 × 2 + 0 × 1 + 100% × 0) = 0.

[0113] In the wind field with a canopy wind speed of 6.0 - 7.5 m / s, the OLD values of the 5 tested varieties were all between 0 and 0.8. Due to their strong or relatively strong lodging resistance, obviously this result does not match the performance of each variety in large-scale production, especially for two varieties with poor lodging resistance in large-scale production, such as Taiyou Nong 39 and Yexiangyou Lisi.

[0114] Application Example 3

[0115] The specific method is the same as that in Application Example 1. The only difference is that when the wind field formed by the unmanned aerial vehicle in the rice canopy is 11.5 - 13.0 m / s, the evaluation and detection results of the lodging resistance of each tested variety are shown in Table 5 below.

[0116] Table 5 Detection Results of Evaluation Indexes for Lodging Resistance of Each Variety of Rice (Wind Speed 11.5 - 13.0 m / s)

[0117]

[0118] For Tianyou Huazhan, the overall lodging degree OLD = (40% × 4 + 30% × 3 + 10% × 2 + 14% × 1 + 6% × 0) = 2.8;

[0119] For Nongxiang 42, the OLD = (54% × 4 + 36% × 3 + 6% × 2 + 4% × 1 + 0 × 0) = 3.4;

[0120] For Yexiangyou Lisi, the OLD = (84% × 4 + 16% × 3 + 0 × 2 + 0 × 1 + 0 × 0) = 3.8;

[0121] For Taiyou Nong 39, the OLD = (80% × 4 + 18% × 3 + 2% × 2 + 0 × 1 + 0 × 0) = 3.8;

[0122] For Y Liangyou 911, the OLD = (24% × 4 + 30% × 3 + 14% × 2 + 20% × 1 + 12% × 0) = 2.3.

[0123] In the wind field with a canopy wind speed of 11.5 - 13.0 m / s, Tianyou Huazhan shows relatively poor lodging resistance, Nongxiang 42, Yexiangyou Lisi and Taiyou Nong 39 show poor lodging resistance, and Y Liangyou 911 shows medium lodging resistance. There are certain differences from the performance of each variety in large-scale production, especially for two varieties with strong or relatively strong lodging resistance in large-scale production, such as Tianyou Huazhan and Y Liangyou 911.

[0124] Application Example 4

[0125] The specific method is the same as that in Application Example 1. The only difference is that when all the tested varieties are in the heading stage to the middle milk-ripe stage (i.e., the heading stage, the middle milk-ripe stage, or any stage between the two stages), when a wind field treatment of 8.0 - 11.0 m / s is carried out above the tested varieties, the evaluation and detection results of the lodging resistance of each tested variety are as shown in Table 6 below:

[0126] Table 6 Detection Results of Evaluation Indexes for Lodging Resistance of Each Variety of Rice

[0127]

[0128] The overall lodging degree OLD of Tianyou Huazhan = (0%×4 + 4%×3 + 10%×2 + 28%×1 + 58%×0) = 0.6;

[0129] The OLD of Nongxiang 42 = (0%×4 + 16%×3 + 22%×2 + 40%×1 + 22%×0) = 1.3;

[0130] The OLD of Yexiangyou Lisi = (6%×4 + 30%×3 + 24%×2 + 14%×1 + 26%×0) = 1.8;

[0131] The OLD of Taiyou Nong 39 = (10%×4 + 34%×3 + 16%×2 + 10%×1 + 30%×0) = 1.8;

[0132] The OLD of Y Liangyou 911 = (0×4 + 0×3 + 0×2 + 34%×1 + 66%×0) = 0.3.

[0133] When a wind field treatment of 8.0 - 11.0 m / s is carried out during the above-mentioned heading stage - middle milk-ripe stage, Tianyou Huazhan and Y Liangyou 911 show strong lodging resistance, Nongxiang 42 has relatively strong lodging resistance, Yexiangyou Lisi and Taiyou Nong 39 show medium performance, which is somewhat different from the performance of each variety in large-scale production, and the overall lodging resistance is relatively high, especially for the two varieties with poor lodging resistance in large-scale production, such as Taiyou Nong 39 and Yexiangyou Lisi.

[0134] Although the above embodiments have described the present invention in detail, they are only a part of the embodiments of the present invention, rather than all embodiments. People can also obtain other embodiments based on this embodiment without creative efforts, and these embodiments all fall within the protection scope of the present invention.

Claims

1. A method for evaluating rice lodging resistance, characterized in that: include: The flying instrument is flown over the target rice to apply a wind field to the rice; the wind field forms a wind speed of 8.0 to 11.0 m / s in the rice canopy; the flying instrument is flown back and forth 2 to 3 times over the target rice to apply the wind field, so that the wind covers the target rice area; After the wind field was applied, the tilt angle of the rice was measured and divided into five tilt intervals according to the tilt angle, namely, plant tilt angle α≤10°, 10°<α≤30°, 30°<α≤45°, 45°<α≤60° and α>60°; Calculate the lodging rate in each tilt interval; the lodging rate in each tilt interval is the ratio of the lodging area in each tilt interval to the total area of ​​the target detection rice area; or, the ratio of the lodging plants in each tilt interval to the total number of plants in the target detection rice area; The degree of lodging in each inclination interval is calculated by lodging degree = lodging rate × inclination angle weight; the inclination angle weight value corresponding to the inclination interval α≤10° is 0, the inclination angle weight value corresponding to 10°<α≤30° is 1, the inclination angle weight value corresponding to 30°<α≤45° is 2, the inclination angle weight value corresponding to 45°<α≤60° is 3, and the inclination angle weight value corresponding to α>60° is 4; The overall lodging degree was obtained by calculating the sum of the lodging degrees in each tilt interval; the overall lodging degree was negatively correlated with the lodging resistance trait of rice.

2. The method according to claim 1, characterized in that: The periods for applying wind fields to rice include the late milky stage and / or the yellowish stage and any period therebetween.

3. The method according to claim 1, characterized in that: The flying instrument is perpendicular to the rice planting row direction when flying.

4. The method according to claim 1 or 3, characterized in that: The flight instrument flies along the central route of the target detection rice area during flight.

5. The method according to claim 1, characterized in that: The flying instrument comprises a multi-rotor drone.

6. The method according to claim 1 or 5, characterized in that: The flying speed of the flying instrument is 2-3 m / s; the flying height of the flying instrument is 1.0-2.0 m from the rice canopy.

7. The method according to claim 1, characterized in that: The tilt angle of rice in the target detection area is measured within 0.5 to 4 hours after the wind field is applied to the rice.

8. The method according to claim 1, characterized in that: 0.0≤overall lodging degree<0.8, the rice has a strong level of lodging resistance; 0.8≤overall lodging degree<1.6, the rice has a relatively strong level of lodging resistance; 1.6≤overall lodging degree<2.4, the rice has a medium level of lodging resistance; 2.4≤overall lodging degree<3.2, the rice has a relatively poor level of lodging resistance; 3.2≤overall lodging degree<4.0, the rice has a poor level of lodging resistance.

9. Use of the method according to any one of claims 1 to 8 in screening rice germplasm resources with resistance to lodging.

10. Use of the method according to any one of claims 1 to 8 in regulating rice cultivation patterns and / or regulating rice quality.

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