一种马铃薯叶面积校正系数的确定方法

目前比较常用的叶面积测定方法中，以叶面积仪、求积仪和计算纸法测量精度最高，而以校正系数法最为简便，易于大范围推广使用。马铃薯由于叶片多且规则程度较差等原因，尚未有简便易行的类似于小麦等作物的叶面积校正系数见报，造成了马铃薯叶面积测定实际操作时难度及误差较大。本文通过试验研究，以计算纸法测定值为标准，确定了马铃薯叶面积另外三种不同测定方法的校正系数：长宽积法叶面积校正系数K为0．76，该方法简单易行、便于推广；机械式求积仪叶面积测量结果为实际面积的92％，测量值需乘以1．09得到比较真实的面积，仪器操作过程繁琐，不便使用；SHY-150型扫描式活体面积仪测量值仅为实际面积的71％，测定值需乘以1．40得到实际面积，由于其价格昂贵、加之对操作过程要求较高容易产生人为误差等原因，影响普遍使用。

A Determination Method of Correction Coefficient of Potato Leaf Area

Among the nine frequently used determination methods of leaf area, the mechanical leaf area meter, SHY-150 and the plot method of multiplying length by width have the highest accuracy. The coefficient method is the simplest one and is easy to promote for use in large scale. We can get the leaf area correction coefficients of main crops from literature, such as rice, wheat, corn, cotton and sorghum, and researches on some economic crops have already been done. However, due to the amount of potato leaves and their irregular shape, there has been no simple and convenient correction coefficient of leaf area similar to that of wheat yet, resulting in the difficulty in actual measurement of the leaf area and directly affecting the measurement accuracy. In this paper, through experimental study, we performed gap analysis of the accuracy of plot method and figured out the correction coefficient with paper measured values as the standard. At the same time, we tested the applicable range, degree and application effects of the mechanical leaf area meter and SHY-150. At last, we recommended using the plot method of multipling length by width to measure the leaf area of Potato, which can take both usability and accuracy into account. Comparison results of the three methods are as follows: 1) There will be certain error in the actual value when using the mechanical leaf area meter. The measured area is only 92 percent of the actual area, so the measurement value needs to be multiplied by 1.09 to get the real area. Measuring Error is big when leaves are small and small when leaves are large. Besides, during the determination process, the reading is error-prone, the machine is difficult to operate, it wastes time and effort, needs higher labor intensity of staff and is inconvenient to use; 2) SHY-150 has a large error, with the measured area being 71 percent of the actual area, and the measurement value needs to be multiplied by 1.40 to get the real area. Moreover, the meter is very expensive and requires higher professional quality of the operator, thus affecting its widespread use; 3) The correction coefficient of the plot method of multiplying length by width is recognized as 0.76 through a large number of complex measurements. As leaves of different sizes and of various development stages were selected, the test result is more stable and universal. You can get a satisfactory result by selecting more than 11 leaves to measure, so we recommend general agricultural meteorology experiment station and scientific research units to use the plot method of multiplying length by width.