A single leaf area measurement method

Abstract

The present application relates to the field of plant growth information measurement, in particular to a single leaf area measurement method, the present application uses a photo enlarger as a light source, places a leaf with known leaf area between the light source and a luxmeter to measure the luminosity value, establishes a standard curve equation according to the linear relationship between the known leaf area and the luminosity value, so as to calculate the leaf area to be measured. The single leaf area measurement method provided by the present application is simple in operation and low in cost, is particularly suitable for the measurement and research of insect feeding amount, and has good sensitivity and accuracy.

Description

Technical Field

[0001] This invention relates to the field of plant growth information measurement, specifically to a method for measuring the leaf area of ​​a single leaf. Background Technology

[0002] Plant leaves are the material basis of photosynthesis, the "green factory" for producing nutrients, and the medium for transpiration. They are not only important indicators of plant growth and development, yield formation, and varietal characteristics, but also crucial tools for rational crop cultivation management and monitoring the occurrence and development of pests and diseases. Measuring the leaf-eating area of ​​leaf-eating insects is an important aspect of studying pest damage losses and economic thresholds.

[0003] Accurate measurement of leaf area is a prerequisite for studying the feeding amount of leaf-eating insects. Currently, there are many methods for measuring leaf area, including the leaf area meter method, the planimetric method, the graph paper method, the weighing method, the graphical decomposition method, the parabolic method, the coefficient method, and the graphical processing method. However, each method has its limitations and scope of application.

[0004] Current methods for measuring leaf area, such as the grid method, weighing method, graphical decomposition method, parabola method, coefficient method, and length-width coefficient method, are cumbersome, computationally complex, time-consuming, labor-intensive, prone to errors, and have relatively large margins of error. Summary of the Invention

[0005] The purpose of this invention is to provide a method for measuring the area of ​​a single leaf.

[0006] The present invention adopts the following technical solution: This invention provides a method for measuring the leaf area of ​​a single leaf, the method comprising the following steps: S1. Place a standard leaf with a known area between the light source and the illuminance meter, and measure the corresponding photometric value; based on the linear correspondence between the area of ​​the standard leaf and the measured photometric value, establish a standard curve equation of leaf area-photometric value. S2. Place the leaf to be tested under the same measurement conditions and measure its photometric value; substitute the photometric value into the standard curve equation to calculate the leaf area of ​​the leaf to be tested.

[0007] This invention designs a method for measuring leaf area suitable for measuring insect feeding rates, called the light flux method. The principle is as follows: under a certain light intensity, the light transmittance over a fixed area is constant. If certain parts of the fixed area are blocked, the light intensity will decrease, and there is a close relationship between the size of the blocked area and the reduction in light intensity. This invention uses a magnifier as the light source and a fixed transmittance area as the provider, and a lux meter to measure the light intensity.

[0008] By measuring the photometric values ​​of leaves with known areas, a linear function relating leaf area and photometric value was established. Through repeated experiments, R0 was identified among all linear functions. 2 (R) 2 The regression coefficient (representing the reliability of the obtained result) has the highest reliability. A standard equation is established for measuring leaf area using photometric methods. Thus, when measuring leaf area, only the photometric value of the leaf needs to be measured, and the result is substituted into the standard equation to deduce the unknown x, thereby obtaining the leaf area value.

[0009] Furthermore, the method also includes measuring the photometric value under unobstructed conditions before each measurement of a leaf with a known leaf area.

[0010] Furthermore, the area of ​​the standard blade is set in a geometric sequence.

[0011] Furthermore, the light source is a photo enlarger, and the photosensitive probe of the illuminance meter is installed on the lens of the enlarger to receive the photometric value after the light source passes through the blades.

[0012] Furthermore, the luminous intensity of the light source is 300~500 Lux.

[0013] Furthermore, the illuminance meter has a measurement range of 0~200000 Lux and an accuracy of ±1 Lux.

[0014] Furthermore, the equation of the standard curve is y = -26.57x + 490.7, R0 2 =0.9987, where y is the leaf area and x is the photometric value.

[0015] Furthermore, the method can be used to measure the amount of food consumed by insects. By measuring the photometric values ​​of the leaves before and after feeding, the difference in leaf area before and after feeding can be calculated, which is the amount of food consumed.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows: By utilizing a photo enlarger and a lux meter, and measuring the luminous flux of leaves, a standard equation is established based on the linear functional relationship between luminous intensity and leaf area. This equation is then used to measure leaf area, offering a novel approach. Furthermore, this method is well-suited for studying insect feeding rates, is easy to operate, and relatively inexpensive, making it an excellent method for measuring leaf area and particularly suitable for measuring insect feeding rates. Attached Figure Description

[0017] Figure 1 This is a picture of a photo enlarger.

[0018] Figure 2 This is a diagram of a digital illuminance meter.

[0019] Figure 3This is a scatter plot of the measurement results of black paper pieces arranged in a geometric sequence for the area of ​​the first measurement.

[0020] Figure 4 The scatter plot shows the measurement results of the black paper pieces arranged in a geometric sequence for the area of ​​the second measurement.

[0021] Figure 5 This is a scatter plot of the measurement results of black paper pieces arranged in a geometric sequence for the area of ​​the third measurement.

[0022] Figure 6 This is a scatter plot of the measurement results of black paper pieces arranged in a geometric sequence for the fourth measurement.

[0023] Figure 7 This is a scatter plot of the measurement results of black paper pieces arranged in a geometric sequence for the area of ​​the fifth measurement.

[0024] Figure 8 A scatter plot of the leaf measurement results, with the area measured in the first measurement arranged in a geometric sequence.

[0025] Figure 9 A scatter plot of the leaf measurement results, arranged in a geometric sequence, showing the area measured in the second measurement.

[0026] Figure 10 A scatter plot of the leaf measurement results, arranged in a geometric sequence, for the area measured in the third measurement.

[0027] Figure 11 This is a scatter plot of the leaf measurement results, arranged in a geometric sequence, for the area measured in the fourth measurement.

[0028] Figure 12 This is a scatter plot of the leaf measurement results, arranged in a geometric sequence, for the area measured in the 5th measurement.

[0029] Figure 13 The first measurement is a scatter plot of the area measured on black paper pieces arranged in an arithmetic sequence.

[0030] Figure 14 The scatter plot shows the area measurement results of the second measurement, with the black paper pieces arranged in an arithmetic sequence.

[0031] Figure 15 The scatter plot shows the area measurement results of the black paper pieces arranged in an arithmetic sequence for the third measurement.

[0032] Figure 16 The scatter plot shows the area measurement results of the fourth measurement, with the black paper pieces arranged in an arithmetic sequence.

[0033] Figure 17 This is a scatter plot of the area measurement results of the 5th measurement, showing the black paper pieces arranged in an arithmetic sequence.

[0034] Figure 18A scatter plot of the leaf measurement results, arranged in an arithmetic sequence, showing the area measured in the first measurement.

[0035] Figure 19 A scatter plot of the leaf measurement results, arranged in an arithmetic sequence, showing the area of ​​the second measurement.

[0036] Figure 20 A scatter plot of the leaf measurement results for the third measurement, arranged in an arithmetic sequence.

[0037] Figure 21 A scatter plot of the leaf measurement results for the fourth measurement, arranged in an arithmetic sequence.

[0038] Figure 22 A scatter plot of the leaf measurement results, arranged in an arithmetic sequence, for the area of ​​the fifth measurement. Detailed Implementation

[0039] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments, but this should not be construed as limiting the invention. Unless otherwise specified, the technical means used in the following embodiments are conventional means well known to those skilled in the art, and the materials, reagents, etc. used in the following embodiments are commercially available unless otherwise specified.

[0040] Implementation Column 1 I. Experimental Materials.

[0041] Photo enlargers manufactured by Fuzhou Optical Instrument Factory No. 2 (see...) Figure 1 The digital illuminance meter manufactured by Shanghai Jiading Student Union Instrument Factory is model JD-3 (see...). Figure 2 Measurement range: 0-200000 Lux, accuracy: ±1 Lux. Tools: scissors, ruler, glass plate, slightly wrinkled 80g black paper, collected from apricot tree leaves at Kewei Garden, Shenyang Agricultural University.

[0042] II. Experimental Methods.

[0043] Remove the lens from the photo enlarger and switch the timer switch to the long-term illumination position. Install the illuminance meter's photosensitive probe onto the enlarger's lens and secure it with transparent tape.

[0044] Establishing a standard curve: Use a ruler and scissors to cut black paper into pieces with areas of 2, 4, 6, and 8 cm². 2 Standard rectangles were clamped with glass plates and inserted into the film compartment of the enlarger. The light intensity was measured and recorded with a lux meter. The light intensity was then added to the light intensity without any obstruction. A standard curve was established with the measured area as the x-axis and the luminance value as the y-axis. This was repeated 10 times.

[0045] Repeat the experiment: Replace the black paper with apple leaf pieces and repeat the above steps.

[0046] First, arrange the leaf areas in an arithmetic sequence: 0, 2, 4, 6, 8 cm². 2 Regression analysis was performed in Excel. Then, leaf area was arranged in a geometric sequence of 1, 2, 4, and 8 cm². 2 Regression analysis can be performed in Excel.

[0047] III. Experimental Results.

[0048] 1. Experimental data of black paper pieces with areas arranged in a geometric sequence The results of the first experiment are shown in Table 1. The rectangular coordinate graph of the results in Table 1 is shown below. Figure 3 .

[0049] Table 1: Luminous flux values ​​measured for the first time The regression equation obtained from the first measurement is: y = -25.08x + 462.0, and the regression coefficient is: R0 2 =0.9938.

[0050] The results of the second experiment are shown in Table 2. The rectangular coordinate graph of the results in Table 2 is shown below. Figure 4 .

[0051] Table 2: Luminous flux values ​​measured in the second measurement The regression equation obtained from the second measurement is: y = -26.19x + 466.2, and the regression coefficient is: R0 2 =0.9923.

[0052] The results of the third experiment are shown in Table 3. The rectangular coordinate graph of the results in Table 3 is shown below. Figure 5 .

[0053] Table 3: Luminous flux values ​​from the third measurement The regression equation obtained from the third measurement is: y = -24.974x + 462.7, and the regression coefficient is: R0 2 =0.9978.

[0054] The results of the fourth experiment are shown in Table 4. The rectangular coordinate graph of the results in Table 4 is shown below. Figure 6 .

[0055] Table 4: Luminous flux values ​​from the fourth measurement The regression equation obtained from the fourth measurement is: y = -25.89x + 464.8, and the regression coefficient is: R0 2 =0.9986.

[0056] The results of the fifth experiment are shown in Table 5. The rectangular coordinate graph of the results in Table 5 is shown below. Figure 7 .

[0057] Table 5: Luminous flux values ​​from the fifth measurement The regression equation obtained from the fifth measurement is: y = -22.65x + 460.7, and the regression coefficient is: R0 2 =0.9794.

[0058] 2. Experimental data of leaf areas arranged in a geometric sequence The results of the first experiment are shown in Table 6. The rectangular coordinate graph of the results in Table 6 is shown below. Figure 8 .

[0059] Table 6: Luminous flux values ​​measured for the first time The regression equation obtained from the first measurement is: y = -26.57x + 490.7, and the regression coefficient is: R0 2 =0.9987.

[0060] The results of the second experiment are shown in Table 7. The rectangular coordinate graph of the results in Table 7 is shown below. Figure 9 .

[0061] Table 7: Luminous flux values ​​measured in the second measurement The regression equation obtained from the second measurement is: y = -21.95x + 464.3, and the regression coefficient is: R0 2 =0.9829.

[0062] The results of the third experiment are shown in Table 8. The rectangular coordinate graph of the results in Table 8 is shown below. Figure 10 .

[0063] Table 8: Luminous flux values ​​measured in the third measurement The regression equation obtained from the third measurement is: y = -24.10x + 466.6, and the regression coefficient is: R0 2 =0.9962.

[0064] The results of the fourth experiment are shown in Table 9. The rectangular coordinate graph of the results in Table 9 is shown below. Figure 11 .

[0065] Table 9: Luminous flux values ​​from the fourth measurement The regression equation obtained from the fourth measurement is: y = -22.35x + 462.3, and the regression coefficient is: R0 2 =0.9984.

[0066] The results of the fifth experiment are shown in Table 10. The rectangular coordinate graph of the results in Table 10 is shown below. Figure 12

[0067] Table 10: Luminous flux values ​​from the fifth measurement The regression equation obtained from the fifth measurement is: y = -22.00x + 462.0, and the regression coefficient is: R0 2 =0.9967.

[0068] 3. Experimental data of black paper pieces whose areas are arranged in an arithmetic sequence The results of the first experiment are shown in Table 11. The rectangular coordinate graph of the results in Table 11 is shown below. Figure 13 .

[0069] Table 11: Luminous flux values ​​measured for the first time The regression equation obtained from the first measurement is: y = -20.05x + 306.8, and the regression coefficient is: R0 2 =0.9754.

[0070] The results of the second experiment are shown in Table 12. The rectangular coordinate graph of the results in Table 12 is shown below. Figure 14 .

[0071] Table 12: Luminous flux values ​​measured in the second measurement The regression equation obtained from the second measurement is: y = -17.35x + 297.6, and the regression coefficient is: R0 2 =0.9470.

[0072] The results of the third experiment are shown in Table 13. The rectangular coordinate graph of the results in Table 13 is shown below. Figure 15 .

[0073] Table 13: Luminous flux values ​​measured in the third measurement The regression equation obtained from the third measurement is: y = -18.5x + 305.8, and the regression coefficient is: R0 2 =0.9674.

[0074] The results of the fourth experiment are shown in Table 14. The rectangular coordinate graph of the results in Table 14 is shown below. Figure 16 .

[0075] Table 14: Luminous flux values ​​from the fourth measurement The regression equation obtained from the fourth measurement is: y = -18.35x + 297.8, and the regression coefficient is: R0 2 =0.9695.

[0076] The results of the fifth experiment are shown in Table 15. The rectangular coordinate graph of the results in Table 15 is shown below. Figure 17 .

[0077] Table 15: Luminous flux values ​​from the fifth measurement The regression equation obtained from the fifth measurement is: y = -17.4x + 301.8, and the regression coefficient is: R0 2 =0.9564.

[0078] 4. Experimental data of leaf areas arranged in an arithmetic sequence The results of the first experiment are shown in Table 16. The rectangular coordinate graph of the results in Table 16 is shown below. Figure 18 .

[0079] Table 16: Luminous flux values ​​measured for the first time The regression equation obtained from the first measurement is: y = -28.10x + 441.4, and the regression coefficient is: R0 2 =0.9488.

[0080] The results of the second experiment are shown in Table 17. The rectangular coordinate graph of the results in Table 17 is shown below. Figure 19 .

[0081] Table 17: Luminous flux values ​​measured in the second measurement The regression equation obtained from the second measurement is: y = -21.15x + 380.8, and the regression coefficient is: R0 2 =0.9502.

[0082] The results of the third experiment are shown in Table 18. The rectangular coordinate graph of the results in Table 18 is shown below. Figure 20 .

[0083] Table 18: Luminous flux values ​​from the third measurement The regression equation obtained from the third measurement is: y = -21.10x + 349.4, and the regression coefficient is: R0 2 =0.9613.

[0084] The results of the fourth experiment are shown in Table 19. The rectangular coordinate graph of the results in Table 19 is shown below. Figure 21 .

[0085] Table 19: Luminous flux values ​​from the fourth measurement The regression equation obtained from the fourth measurement is: y = -13.45x + 288.6, and the regression coefficient is: R0 2 =0.9142.

[0086] The results of the fifth experiment are shown in Table 20. The rectangular coordinate graph of the results in Table 20 is shown below. Figure 22 .

[0087] Table 20: Luminous flux values ​​from the fifth measurement The regression equation obtained from the fifth measurement is: y = -16.75x + 308.8, and the regression coefficient is: R0 2 =0.9736.

[0088] To determine the reliability of the photometric method for measuring leaf area, numerous experiments are needed to observe the variation and error of each experiment. In specific experiments, photometric values ​​were measured on black paper with the best shading and on actual leaves. The measured areas were compared and judged using both arithmetic and geometric series methods.

[0089] 5. Measured Results The actual measurement results are shown in Tables 21 to 24.

[0090] Table 21: Data from Black Paper Pieces in a Geometric Sequence Table 22: Geometric Sequence Leaf Data Table 23: Arithmetic Sequence Data on Black Paper Pieces Table 24: Arithmetic Sequence Leaf Data 6. Comparison of regression equations Based on the above experimental results, the corresponding regression equations were established, and the specific results are shown in Tables 25-26.

[0091] Table 25: Geometric Regression Equation Table 26: Arithmetic Regression Equations The experimental data reveals the following phenomena and patterns: As the area of ​​the object being measured increases, the photometric value gradually decreases, and the change is basically linear.

[0092] The photometric value corresponding to a measured area of ​​0 is referred to here as the 0 value. Its stability is quite poor; simply put, the results vary significantly from measurement to measurement. Here's a brief analysis of the factors contributing to the instability of the 0 value:

[0093] 1) Factors related to the instability of the instrument itself. The main instruments used, such as the amplifier and lux meter, may not be accurate enough, leading to changes in the zero value.

[0094] 2) The effect of temperature change on the magnifier. During the experiment, we discovered that as the magnifier's operating time increased, its temperature became considerably higher. The light transmittance of the magnifier at high temperatures differed significantly from that at low temperatures. Under the existing experimental conditions, it was impossible to measure and determine the exact relationship between temperature and the final photometric value. However, it is certain that the magnifier's temperature change directly affects the final photometric value measurement, and consequently, the accurate measurement of leaf area.

[0095] 3. The photometric value measured by the photometer is not constant. The value measured by the photometer is not stable and unchanging; it varies within a certain range, roughly around 20. Therefore, the final data recording only records a relatively accurate value, and cannot guarantee 100% accuracy.

[0096] The variation range of the measurement method for geometric sequences is smaller than that for arithmetic sequences. Experiments showed that the R² of the formula derived from measuring leaf area using a geometric method was significantly smaller than that derived from measuring using an arithmetic sequence. 2 The closer R is to 1, the smaller its range of variation and error. 2 The equation closest to 1 appeared in the first experiment of measuring leaf area using a geometric sequence, and is therefore considered the standard formula for leaf area measurement: y = -26.57x + 490.7, R. 2 =0.9987.

[0097] IV. Results Analysis.

[0098] 1. Method sensitivity analysis To test the sensitivity of photometric leaf area measurement, a 4cm leaf area was selected in the experiment. 2 and 5cm 2 The photometric values ​​of the leaves were measured five times, and the differences in photometric values ​​were observed. Since the difference in photometric values ​​was found to be significant at the zero value, and this had a decisive influence on the accurate representation of leaf area, the zero value was accurately reflected in each measurement experiment. The measured data are as follows:

[0099] Table 27: Sensitivity Experiment Results Through observation and analysis of the data, it can be seen that under the same 0 value, the change in photometric value is still very obvious. Therefore, it can be concluded that if the 0 value is stable, that is, if the experimental equipment can guarantee considerable accuracy and constancy, the change in photometric value can well reflect the different numerical changes of leaves with similar areas. Therefore, it can be said that the sensitivity of this measurement method basically meets the requirements.

[0100] 2. Method accuracy analysis To determine the accuracy of the photometric method for measuring leaf area, it is necessary to input the original experimental data into the linear equation derived from the experimental data and observe the difference between the result obtained by the equation and the original experimental result, that is, to compare the range of difference between the leaf area calculated by the formula and the actual leaf area.

[0101] Table 28: Error Data for Black Paper Pieces in Geometric Sequences Table 29: Arithmetic Sequence Blade Error Data The conclusions can be drawn by observing the error data: Geometric sequences have smaller equation errors compared to arithmetic sequences.

[0102] 2cm in an arithmetic sequence 2 The actual photometric values ​​at each point are all lower than the photometric values ​​calculated by the formula, and the differences are significant. This indicates that the actual equation curve at that point is not a straight line, but rather a curve.

[0103] Overall, the error rate is good, indicating that the experimental design method is accurate.

[0104] V. Conclusion.

[0105] Since changes in the 0 value have a significant impact on experimental results, when measuring leaf area using the photometric method, an experiment to determine the equation of the standard curve must be performed before each measurement to ensure the accuracy and reliability of the measured results.

[0106] Observation of error data revealed that the equation error of a geometric sequence is smaller than that of an arithmetic sequence. In an arithmetic sequence, the error is smaller at 2cm. 2 The actual photometric values ​​were all lower than the photometric values ​​calculated by the formula, and the differences were significant. This indicates that the actual equation curve is not linear at some points. If other curves were used, the coefficient of variation would be smaller, potentially yielding more accurate results. This is a topic that requires further investigation.

[0107] The change in photometric value can effectively reflect the different numerical changes of leaves with similar areas. Therefore, the photometric method for measuring leaf area has good sensitivity.

[0108] This experimental method is relatively simple to operate and extremely inexpensive. Therefore, it is more suitable for measuring insect feeding.

[0109] It should be noted that when numerical ranges are mentioned in the claims of this invention, it should be understood that the two endpoints of each numerical range and any value between the two endpoints can be selected. To avoid redundancy, the present invention describes preferred embodiments.

[0110] Although preferred embodiments of the invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of the invention.

[0111] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A method for measuring the area of ​​a single leaf, characterized in that, The method includes the following steps: S1. Place a standard leaf with a known area between the light source and the illuminance meter, and measure the corresponding photometric value; based on the linear correspondence between the area of ​​the standard leaf and the measured photometric value, establish a standard curve equation of leaf area-photometric value. S2. Place the leaf to be tested under the same measurement conditions and measure its photometric value; substitute the photometric value into the standard curve equation to calculate the leaf area of ​​the leaf to be tested.

2. The method for measuring the area of ​​a single leaf according to claim 1, characterized in that, The method also includes measuring the photometric value without obstruction before each measurement of a leaf with a known leaf area.

3. The method for measuring the area of ​​a single leaf according to claim 1, characterized in that, The area of ​​the standard blade is set in a geometric sequence.

4. The method for measuring the area of ​​a single leaf according to claim 1, characterized in that, The light source is a photo enlarger, and the photosensitive probe of the illuminance meter is installed on the lens of the enlarger to receive the photometric value after the light source passes through the blades.

5. The method for measuring the area of ​​a single leaf according to claim 1, characterized in that, The luminous intensity of the light source is 300~500 Lux.

6. The method for measuring the area of ​​a single leaf according to claim 4, characterized in that, The illuminance meter has a measurement range of 0~200000 Lux and an accuracy of ±1 Lux.

7. The method for measuring the area of ​​a single leaf according to claim 1, characterized in that, The standard curve equation is y = -26.57x + 490.7, R0 2 =0.9987, where y is the leaf area and x is the photometric value.

8. The method for measuring the area of ​​a single leaf according to claim 1, characterized in that, The method is used to measure the amount of food consumed by insects. The difference in leaf area before and after feeding is calculated by measuring the photometric values ​​of the leaves before and after feeding, which is the amount of food consumed.

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