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OLS Field Name OLS Field Data
Main Title Water Relations of Differentially Irrigated Cotton Exposed to Ozone.
Author Temple, P. J. ;
CORP Author California Univ., Riverside.;Corvallis Environmental Research Lab., OR.
Publisher c1990
Year Published 1990
Report Number EPA/600/J-90/469;
Stock Number PB91-183202
Additional Subjects Air pollution effects(Plants) ; Ozone ; Soil-water-plant relationship ; Drought tolerance ; Cotton plants ; Field tests ; Biological stress ; Crop production ; Growth inhibitors ; Exposure ; Plant growth ; Soil water ; Irrigation ; Agronomy ; Water utilization ; Reprints ; Riverside(California)
Holdings
Library Call Number Additional Info Location Last
Modified
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Status
NTIS  PB91-183202 Most EPA libraries have a fiche copy filed under the call number shown. Check with individual libraries about paper copy. NTIS 09/04/1991
Collation 9p
Abstract
The field study was conducted to test the hypothesis that plants chronically exposed to O3 may be more susceptible to drought because O3 typically inhibits root growth and increases shoot-root ratios in plants. Cotton was grown in open-top chambers on Hanford coarse sandy loam in Riverside, CA. Plants were grown under three irrigation regimes: optimum water for lint production (OW), suboptimum or moderate drought stress (SO), and severely drought stressed (SS) and were exposed to seasonal 12 h (0800-2000) O3 concentrations of 0.015, 0.074, 0.094, or 0.111/microLL. Leaf xylem pressure potentials Psi(sub 1) and soil water content Theta(sub v) were measured weekly from June to October. Mean seasonal Psi(sub 1) increased from -1.89 MPa to -1.72 MPa in low to high O3 treatments, averaged across soil water regimes. Ozone had no effect on seasonal water use of cotton, but water use efficiency was significantly reduced by O3 in OW and SO, but not in SS treatments. Drought-stressed plants extracted proportionally greater amounts of water from deeper in the soil profile than OW cotton, and O3 had no apparent effect on this redistribution of roots in the soil. Since O3 had no apparent effect on the ability of drought-stressed cotton to maintain Psi(sub 1) and to increase root growth relative to shoot growth, this suggests that O3 may have little or no effect on the potential of cotton to adapt to or tolerate drought.