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The Center for Native Grasslands Management

Title: Temperature and CO2 effects on Eastern Gamagrass: Photosynthetic performance
Year: 2002
Author(s): Gitz, III, D. C., Ritchie, J. C., Baker, J., Krizek, D. T., Reddy, V. R.
Source Title: Proceedings of the Third Eastern Native Grass Symposium
Source Type: Proceedings
pages: 203-210
Original Publication:  
Abstract: Eastern gamagrass was grown in large 1 m3 bins on a sand:vermiculite mix with regular fertigation with a complete nutirent solution in closed transparent cuvettes at 370 or 740 micro mold mol-1 CO2 and 20/14 degrees Celcius or 35/29 degrees Celcius day/night temperatures. Plants were allowed to develop from mid-May to mid-October. Leaf and canopy photosynthesis was investigated. Physiological parameters from leaf based observations were consistent with canopy level observations. Temperature effects on assimilation rates, and quantum use efficiencies as CO2 assimilation vs photosyntheitcally active radiation and as Fv/Fm, the ratio of day/night) the maximum rate of carbon assimilation was reached at relatively low PAR levels 91500 micro mol m-2 s-1) compared to high temperature plants (35/29 degrees Celcius day/night) which peaked at 2500 micro mol m-2 s-1. Photon flux utilization experiments demonstrated that enhanced CO2 decreased maximal photosynthetic rates across treatments. This was most pronounced in plants grown at the lowest temperature.
Publisher: The North Carolina Botanical Garden, Chapel Hill, NC, October 1-3, 2002. Omnipress, Madison, WI
Editor(s): J. Randall