Spectral differentiation of wheat, mustard and chickpea crops grown under variable water supply situations

Spectral differentiation of wheat, mustard and chickpea grown under variable water supply was done by using hand held spectro-radiometer and infra-red thermometer. Red and infra-red reflectance from the crop canopy and canopy thermal environment through canopy-air temperature difference were recorded at various stages of the crop growth. Spectral indices, such as IR/R, Normalized Difference Vegetation Index (NDVI) and Infrared-Red (IR-R, from the spectro-radiometric observation) and cumulative stress degree days were developed, which were subsequently used to differentiate these crops through Leaf Area Index (LAI), biomass and final grain yield. The three crops were spectrally variant among themselves as well as within each crop grown under differential sequence of limited/moderate inputs of water. This study, through development of transfer function for linking with satellite derived indices, can effectively assist in operational satellite remote sensing for crops’ discrimination, crops’ growth condition assessment and yield forecasting.