An inexpensive, accurate method for measuring leaf area and defoliation through digital image analysis
An inexpensive, accurate method for measuring leaf area and defoliation through digital image analysis
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DOI：
10.1603/0022-0493-95.6.1190
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发表时间：
2002-12-01
影响因子：
2.2
通讯作者：
Isaacs, R
中科院分区：
文献类型：
--
作者：
O'Neal, ME;Landis, DA;Isaacs, R
我们报告了一个协议，使用一个共同的台式扫描仪和公共领域的软件测量现有的叶面积和叶面积作为结果的植食动物。我们比较了这种方法的准确性和精密度的标准叶面积计，这两种方法被用来测量金属圆盘的已知面积，大豆（Glycine max L）叶片的面积，并通过模拟叶片饲养与打孔器去除的面积。我们在低、中和高程度的模拟进食中改变了损伤量。用叶面积计比用台式扫描仪更准确地估计10 cm（2）和50 cm（2）金属圆盘的平均面积。两种方法的叶面积估计值高度相关，台式扫描仪准确地估计了从低、中或高程度的模拟叶片喂养中去除的叶面积。然而，叶片尿素仪高估了低水平的模拟取食伤害。虽然用台式扫描仪测量树叶的表面积需要两个步骤（创建数字图像文件并计算该图像所代表的面积）。测量叶损伤所需的总时间比用叶面积计短。这种相对简单和廉价的方法估计叶面积和喂养的损害具有优势，在某些实验情况下，叶的预喂养测量是不可能的或不可取的，或当少量的喂养发生。
We report a protocol using a common desk-top scanner and public domain software for measuring existing leaf area and leaf area removed as a result of herbivory. We compared the accuracy and precision of this method to that of a standard leaf area meter, Both methods were used to measure metal disks of a known area, the area of soy bean (Glycine max L) leaves, and the area removed by simulating leaf feeding with a hole-punch. We varied the amount of injury across a low, medium, and high degree of simulated feeding. The mean area of 10 cm(2) and 50 cm(2) metal disks was more accurately estimated with the leaf area meter than the desk-top scanner. Leaf area estimates from both methods were highly correlated, The desk-top scanner accurately estimated the leaf area removed from the low, medium, or high degree of simulated leaf feeding. However, the leaf urea meter overestimated low levels of simulated feeding injury. Though measuring a leafs surface area with a desk-top scanner requires two steps (creating a digital image file and calculating the area represented by that image). the overall time required to measure leaf injury is shorter than with a leaf area meter. This relatively simple and inexpensive method of estimating leaf area and feeding damage has advantages in certain experimental situations where a prefeeding measurement of the leaf is impossible or undesirable or when small amounts of feeding occur.