The correlative relationship in the reflectance spectra

first derivative spectra of canopies and the chlorophyll content of early\|planted rice

late\|planted rice

and maize has been discussed. It shows that their correlative relationship is good

especially for the first derivative spectral data at the waveband 762 nm. Therefore

the same regression equation can be calculated for different crops. The linear regression equation has been built by using the first derivative spectral data of a part of samples at waveband 762 nm to estimate the chlorophyll content. Through the test of the other part of samples

it shows that the standard error is 0.272g/m\+2

and the estimated accuracy is about 80%.