Ozone and Sulfur Dioxide Effects on Three Tall Fescue Cultivars
1982
Flagler, R. B. | Youngner, V. B.
Although many reports have been published concerning differential susceptibility of various crops and/or cultivars to air pollutants, most have used foliar injury instead of the marketable yield as the factor that determined susceptibility for the crop. In an examination of screening in terms of marketable yield, three cultivars of tall fescue (Festuca arundinacea Schreb.), ‘Alta,’ ‘Fawn,’ and ‘Kentucky 31,’ were exposed to 0–0.40 ppm O₃ or 0–0.50 ppm SO₂ 6 h/d, once a week, for 7 and 9 weeks, respectively. Experimental design was a randomized complete block with three replications. Statistical analysis was by standard analysis of variance and regression techniques. Three variables were analyzed: top dry weight (yield), tiller number, and weight per tiller. Ozone had a significant effect on all three variables. Significant linear decreases in yield and weight per tiller occurred with increasing O₃ concentrations. Linear regressions of these variables on O₃ concentration produced significantly different regression coefficients. The coefficient for Kentucky 31 was significantly greater than Alta or Fawn, which did not differ from each other. This indicated that Kentucky 31 was more susceptible to O₃ than either of the other cultivars. Percent reductions in dry weight for the three cultivars at highest O₃ level were 35, 44, and 53%, respectively, for Fawn, Alta, and Kentucky 31. For weight per tiller, Kentucky 31 had a higher percent reduction than the other cultivars (59 vs. 46 and 44%). Tiller number was generally increased by O₃, but this variable was not useful for determining diffferential susceptibility to the pollutant. Sulfur dioxide treatments produced no significant effects on any of the variables analyzed.
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