Fluorescence responses from nitrogen plant stress in 4 Fraunhofer band regions

The potential of solar Fraunhofer line features centered at 532, 607, 677 and 745nm for tracking changes in plant canopy chlorophyll content and photosynthetic capacity was studied. Excitation wavelengths similar to full sun light were considered. Canopy changes were tested experimentally by monitoring treatments of plant stress due to nitrogen application rate in corn. Corn leaves were obtained from field plots that were given different nitrogen application rates at 20, 50, 100, and 150% of optimal N in 2001. The data infers that leaves in plant canopies that have the greatest photosynthetic performance potential can be identified. Information collected in Fraunhofer regions compared favorably with data taken by laser induced fluorescence excitation and detection methods in peak emission areas. The technique may be useful in projecting what can be expected if a space-born interferometer type sensor can be developed for capturing plant canopy fluorescence.