Statistical Separability of Spectral Classes of Blighted Corn

The purpose of this study was to determine the statistical separability of multispectral measurements from corn having varying levels of southern corn leaf blight severity. Multispectral scanner data in twelve spectral channels in the wavelength range 0.4 to 11.7 pm were analyzed for ten selected flightlines of the 1971 Corn Blight Watch Experiment. A total of 168 corn fields having 18,804 sample points were analyzed. The blight rating information for these ,fields were available. Maximum average transformed divergence between spectral classes (found by LARSYS Cluster Algorithm) of !!! possible pair of blight levels, maximized over a subset of channels, was computed in each of one, two, three, and four spectral channels for each of ten flightlines. Prom the statistical analysis of the values of average transformed divergence, it was concluded that the greater the difference between the blight levels, the .ore statistically separabl~ they are. This result is encouraging considering the fact that there are variables other than the blight severity within and between fligbtlines. Although the analysis was ~one for corn bligbt only, the conclusions obtained 2 from this analysis may well be applicable to other crop stresse.