Remote detection of nutrient stress in groundnut plants by deconvolution of laser-induced fluorescence spectra

Laser-induced fluorescence (LIF) signatures from plants are being applied for remote detection of vegetation stress using the inverse relationship between the in vivo chlorophyll fluorescence and photosynthesis. When photosynthetic activity declines, the fluorescence intensity ratio of the chlorophyll bands F690/F730 increases. Minor variations in this ratio due to changes in plant health is not easily detectable from the LIF spectra. The present study aims at improving the sensitivity of these ratios by using Gaussian spectral functions to deconvolute the LIF spectra into its constituent bands and to utilize the constituent band parameters, such as peak centre, peak amplitude and Gaussian curve areas, for stress evaluation. The results of laboratory measurements on two varieties of groundnut plants subjected to nitrogen, phosphorus and potassium deficiencies are presented