Submitted to: American Society of Agronomy Meetings
Publication Type: Abstract Only
Publication Acceptance Date: October 22, 2001
Publication Date: October 22, 2001
Technical Abstract: The primary objective was to evaluate multispectral fluorescence responses as a noninvasive detection method for crop species subjected to elevated atmospheric CO2 and O3 under two soil moisture regimes. A laboratory-based fluorescence imaging system (FIS) was developed to capture and process images of plant leaves at the blue (F450), green (F550), red (F680), and far-red (F740) regions of the spectrum. Full surface imaging was superior to point source measurements in assessing fluorescence characteristics of plant leaves. Field experiments were conducted at the USDA Beltsville Agricultural Research Center using soybean cultivars 'Essex' and 'Forrest' grown full-season in open-top chambers exposed to four combinations of tropospheric CO2 and O3 under well-watered (WW) vs. restricted moisture (RM) conditions. The results from this investigation demonstrated that chronic exposures of soybean leaves to air quality treatments varying in O3 and CO2 concentrations produced significant alterations in multispectral fluorescence responses even in the absence of visual symptoms. Likewise, soil moisture treatments caused significant changes in fluorescence responses throughout the spectrum.