Quantifying Relative Canopy Temperature, Fraction of Radiation Intercepted, and Greenness Intensity of Crops from an Aerial Platform.

Aerial images of research experiments on soybean and other crops have the potential to provide information on differences in how genotypes respond to nutrition, drought stress, and disease. A critical component that is lacking for using this information is interpretation of the data and the ability to quantify data on individual plots quickly and easily. This research reports the development of customized software that divides aerial images of field experiments into grids corresponding to experimental plots. The software has selections that allow bordered regions of the plots to be excluded from measurements, and the software has options for analyzing images from color infra-red (IR), gray-scale IR, dark green color index (DGCI), and fraction of radiation intercepted. Data from an entire field can be analyzed at once, and the output is saved in a csv-format that can be opened in a spreadsheet. Aerial color images from irrigated and rainfed soybean experiments in 2015 were taken throughout seedfill and used to determine DGCI, which is closely associated with nitrogen concentration. Analysis of DGCI data using the software had near perfect agreement with analysis of DGCI values determined from measuring individual plots but required only a fraction of the time.