Morphological responses among crop species to full-season exposures to enhanced concentrations of atmospheric CO2and O3
✍ Scribed by C. Mulchi; B. Rudorff; E. Lee; R. Rowland; R. Pausch
- Publisher
- Springer Netherlands
- Year
- 1995
- Tongue
- English
- Weight
- 454 KB
- Volume
- 85
- Category
- Article
- ISSN
- 0049-6979
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✦ Synopsis
Field studies using open-top chambers were conducted at USDA-BARC involving the growth of soybeans ('89 & '90), wheat ('91 & '92), and corn ('90, under increased concentrations of atmospheric CO2 and Os. Treatment responses were compared in all cases to plants grown in charcoal-filtered (CF) air (seasonal 7-h mean = 25+3 n mol 03 reel -1) having 350 or 500/z mol CO: mol a. Elevated seasonal Os levels for the soybean, wheat, and corn studies averaged 72.2+4, 62.7+2, and 70.2 n reel 03 mo1-1, respectively. Results presented were obtained for plants grown in silt loam soil under well-watered conditions. Grain yield increases in response to elevated CO: in the absence of O: stress averaged 9.0, 12.0, and 1.0 % for soybean, wheat, and corn,*respectively. Reductions in grain yields in response to the elevated O: treatments at 350/~ mol CO: reel -1 averaged 20.0, 29.0 and 13.0% for soybean, wheat, and corn, respectively. Reductions in grain yields in response to elevated O: at 500/~ mol CO: reel -1 averaged 20.0, 8.0, and 7.0% for soybean, wheat, and corn, respectively. Dry biomass and harvest index in wheat were significantly reduced by O: stress at 350 tz reel mol 1 CO: but not at 500 u reel mol a CO:. Seed weight 10001 for soybeans and wheat was significantly increased by CO 2 enrichment and decreased by O: stress. Seed weight 10001 in corn was increased by O 3 stress suggesting that 03 affected pollination resulting in fewer kernels per ear.