Aim of the Ph.D. thesis was the detection of the canopy water mass and temperature, as well as the aerial biomass and nitrogen uptake of several tropical maize hybrids (Zea mays L.) experiencing different drought stress treatments, and also detecting the contributions of the different leaf levels of maize canopies on spectral reflectance. IR-temperature as well as spectral indices displayed a high correlation with canopy water mass and could also accurately estimate the aerial biomass and above ground nitrogen uptake of maize, while differentiating the drought stress levels and also classifying consistently the hybrids. The sensor could also detect the aerial biomass and nitrogen uptake of the lowest leaf levels and furthermore the vertical distribution of chlorophyll, aerial biomass and nitrogen uptake in maize canopies was demonstrated.