Submitted to: Remote Sensing of Environment
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: April 18, 2001
Publication Date: October 15, 2001
Interpretive Summary: Studies indicate potential for spectral fluorescence technology at the field cropping level but the technology is in its infancy in regards to its actual use in agricultural practice. Some projected applications of fluorescence in agriculture include precision management of nitrogen fertilizers, detection of crop stresses, detection of weed species for precision spraying, crop residue management and detection of spectral markers inserted in plant genomes. Fluorescence technologies for monitoring the cropping system attributes in the agricultural scene are relatively new concepts that have been introduced to a small audience. They will need further improvements and extensive evaluations to fully develop their potentials. A number of possible uses for agricultural applications are illustrated.
A number of fluorescence techniques have been suggested for monitoring various crop attributes in the agricultural scene. In live crop material red fluorescence induction kinetics have shown to be highly related to photosynthetic efficiency. Ratios of red to far-red fluorescence steady state emissions have also been successful in determining photosythesis status as well as chlorophyll concentration. Blue to green fluorescence emission ratios as well as blue to red, green to red, blue to far-red and green to far-red ratios have shown relation to the physiological status within crop species. Fluorescence of dead crop residues in the blue-green area of the spectrum are useful in detecting crop residue coverage for soil erosion control as well as postmortem indicators of the past crops performance and production. Ultra-violet (UV) fluorescence emission has been related to total protein concentration in live and dead crop material. .Selecting optimal excitation wavelength depends on the application desired and the ability to construct a workable system. Five primary areas (UV, blue, green, red and far-red) have been identified as providing useful information for the management of crop materials. Fluorescence technologies are rich with information on the electron transfer efficiencies within plants. The answers to the capturing to the suns energy, electron transfer and the building of plant materials are complex and much work must be done to fully understand their total implications. However, several simple approaches useful to the management of cropping systems are now ready for further development.