Spectral signatures of moisture-stressed wheat

One of the important parameters affecting crop yield is the availability of soil moisture to the crop. Lackof it may bring about moistur~ stress in plants which manifests itself in terms of changes in the spectral reflectance and emittence properties of plants. An experiment involving radiometric measurements over six wheat plots subjected to different irrigation schedules was conducted to test this hypothesis, Vegetation index defined in terms of cropreflectances in 0.6 to 0.7 and 0.8 to 1,1 micrometer bands was found to ben sensitive parameter to distinguish normal plants from moisture-stressed plants. The optimum period for the discrimination of such plants through remote sensing techniques has been indicated to be 45-80 days after sowing. The experiment also demonstrates that yield per unit area is linearly related to the maximum leaf-area index of the crop thus providing a possible method of crop yield prediction