Abstract:

In order to measure leaf area of cotton, a new method for measuring leaf area of cotton was developed by using scanner and GIS. First, the digital images of the cotton leaves and standard graphics were gotten through the scanner. Secondly, the digital images were vectored, and then the data of area and perimeter of rectangle, isosceles triangle, square and right triangle were extracted by using the GIS spatial analysis. The results showed that, compared to actual values of standard graphics, average relative error of area and perimeter extracted were 0.021 and 0.01, respectively, which was less than the measurement error gained by leaf area meter. Therefore, it was feasible to measure leaf area of cotton by means of GIS spatial analysis. Moreover, the GIS spatial analysis was not affected by the factors of leaf shape, size, thickness and tender leaves. For the plant with small leaf area, it could automatically output abundant data by using GIS batch data processing function. Compared with other methods of measuring leaf area, the GIS spatial analysis had the merits of precision, fast and abundance data, and it could be extended in the fields of production and scientific research.