With the development of agricultural science and technology, there are advantages and disadvantages in various methods for determining the leaf area of ​​plants. At the same time, there are certain links and complementary features between many methods. Each method has its own measurement results. And the test process has the measurement purpose that researchers need. The area of ​​the mature summer shoots of the four different varieties was determined as the research object, and the method used was different. For each measurement, a corresponding regression equation was established for the leaves. The main areas of the test method that include leaf area scanners are:
The grid method describes the outline of the blade on the standard calculation paper (the product produced by the Shanghai Tianzhang Recorder and the minimum square size is 1mm×1mm), and the number of small squares occupied by the leaf outline is counted (the number that reaches or exceeds the half-lattice One cell, less than half-cell, is the leaf area determined by the grid method.
The planimeter method plots the outline of the blade on ordinary drawing paper, measures the area occupied by the contour of the leaf by a planimeter at a ratio of 1:1, and the number of measurements per leaf is not less than twice, and the difference is not more than 0.5cm2. The average of the two results is the area measured by the planimeter method for this leaf.
The leaf area scanner uses the YMJ-A leaf area scanner to measure the area of ​​each leaf, and the number of measurements per leaf is not less than 2 times. The average of the two readings with a reading difference of no more than 0.5cm2 is the leaf area. The accuracy of this instrument is high, and the relative error of the measurement does not exceed 1%.
Methods for determining the area of ​​the loquat leaf are all available. However, the fresh weight method must be operated very quickly, otherwise it will lose water quickly and affect the accuracy. Both the fresh weight method and the paper weight method must have very accurate balances to obtain accurate results. The grid method, the paper weight method and the planimeter method are difficult to operate in the case of leaf-bearing trees. Generally, it is necessary to take off the leaves to facilitate the description of leaf outlines, and the measurement method is also cumbersome.
The leaf area scanner method requires more expensive equipment. In contrast, the linear regression estimation method and the coefficient method are the simplest ones. Once the regression equation is established and the coefficients are calculated, a large number of blades can be quickly determined in the presence of the leaves and the accuracy can be determined. It is also high and worth advocating.
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