In the process of plant growth, photosynthesis of plants is a very important life activity, so the health of the leaves has a very important influence on the growth of plants. The leaves of plants are applied to biological biochemistry, physiology and ecology, and crop cultivation. Therefore, it is of great significance to the accuracy or deficiency of the leaf area per unit of the subject. There are many methods for measuring the leaf area, such as leaf area measurement, grid paper or weighing, etc., to investigate leaf area. The use of a living leaf area meter for the measurement of the leaf area of ​​Tripterygium wilfordii has a very conspicuous advantage, that is, there is no need to destroy the leaf, and the area of ​​the leaf can be determined accurately. This ensures the healthy state of growth of Tripterygium wilfordii, and the application of the living leaf area meter accelerates the determination of the leaf area and improves the research efficiency.
Tripterygium is widely distributed in the southern provinces of the Yangtze River Basin, and is an important medicinal material for the treatment of diseases such as rheumatism, nephritis, and surgical skin diseases. There are dozens of pharmaceutical companies that use Tripterygium as raw materials. Tripterygium leaves, branches, roots, etc. The parts contain active ingredients such as formazan, and the leaves are also the main raw materials for extraction of medicinal ingredients. Using leaf area meter to study the leaf area of ​​Tripterygium wilfordii has practical significance for the prediction of leaf yield.
The coefficient determined by the linear relationship between the length of the blade and the product of the maximum width and the actual area of ​​the blade is called the leaf area index. The leaf area coefficient K = leaf area A (leaf length @ leaf width). The leaf area coefficient is constrained by the leaf shape. The leaf shape is controlled by several pairs of alleles, photoperiods, and temperature. Therefore, different leaf species, leaf age, and environment have different leaf area coefficients. Bryan et al. believe that leaf area coefficient varies between years. There was a slight change, but remained basically stable during the same year.
By fitting, there was a high positive correlation between leaf length, leaf width, leaf length @ leaf width and leaf area of ​​Tripterygium wilfordii, of which leaf length @ leaf width and leaf area had the highest correlation coefficients, followed by leaf width. The leaf length regression equation is the smallest, and the three simple linear regression equations reach extremely significant levels. The one-dimensional linear regression equation y=-0.318406+0.6607429x which can be used to determine the relationship between the leaf area and the leaf length-width product can be used as the leaf area estimation equation. The measured results are more accurate. Using the three empirical formulas to calculate the theoretical value of the total leaf area of ​​about 100 leaves compared with the actual value, the error between the measured value and the actual value of the spindle-shaped formula is the smallest, and the error is within 3%. This method is accurate, simple, and fast. The calculation formula for the area of ​​Tripterygium wilfordii leaves is used in production practice.