Water stress and elevated carbon dioxide effects on
photosynthesis and growth in corn. (C02-niu981317-poster)
Authors:
G. Niu* - USDA-ARS, Alternate Crop and Systems Lab D. Timlin - USDA-ARS, Alternate Crop and Systems Lab V.R. Reddy - USDA-ARS, Alternate Crop and Systems Lab S. Kim - USDA-ARS, Alternate Crop and Systems Lab D. Gitz - USDA-ARS, Alternate Crop and Systems Lab
Abstract:
Water stress often limits corn (Zea mays L.) grain yield. Although the effect of water stress on crop growth and development, physiology, and yield has been widely studied, relatively little information is available on water stress effect under elevated carbon dioxide concentration. The objective of this study was to quantify the effect of water stress imposed at vegetative and/or reproductive stages on
photosynthesis and evapo-transpiration rates, vegetative growth, and development of corn plants under ambient (370 ppm) or elevated (750 ppm) carbon dioxide concentrations. Sunlit, controlled outdoor SPAR (Soil-Plant-Atmosphere-Research) chambers were used. Air temperatures in all chambers were maintained constant (31/25 oC, day/night). Chamber environmental data (air and soil temperatures, humidity, light intensities above and under canopy, carbon dioxide concentrations, water content in the soilbins at various depths) were monitored and recorded. Canopy photosynthesis and
evapo-transpiration rates were estimated from the canopy gas exchange measurement of the chambers.
Effect of water stress imposed during vegetative and/or reproductive stages and the impact of elevated carbon dioxide concentration on growth parameters, rates of photosynthesis, evapo-transpiration, and water uptake, and grain yield will be evaluated in this paper.
Speaker Information: Genhua Niu, USDA-ARS, Alternate Crop and Systems Lab, Alternate Crops and Systems Lab Bldg 001, Rm 201, Beltsville, MD 20705; Phone: 301-504-9838; E-mail:
Session Information: Tuesday, November 4, 2003, 4:00 PM-6:00 PM Presentation Start: 4:00 PM (Poster Board Number: 917)
Keywords: corn; water stress; elevated carbon dioxide; photosynthesis
