The Effect of Acute Ozone Exposures on the Growth of Hybrid Poplar. Ronald Harkov, Former Graduate Student, Department of Plant Pathology, Rutgers University, New Brunswick, NJ 08903. Eileen Brennan, Professor, Department of Plant Pathology, Rutgers University, New Brunswick, NJ 08903. Plant Dis. 66:587-589. Accepted for publication 8 October 1981. Copyright 1982 American Phytopathological Society. DOI: 10.1094/PD-66-587.

Rooted cuttings of hybrid poplar (Populus maximowiczii × P. trichocarpa, clone 388) were exposed in a controlled chamber to 400 µg/m³ of ozone for 5 hr two, three, four, or five times during a 1-mo period. About 60–80% of the leaves developed toxicity symptoms on 10–25% of the total leaf area. Ozone had no statistically significant effect on total dry weight, leaf area, elongation, relative growth rate, or net assimilation rate of the total plant population, but the trend was toward a reduction in each of these variables. A few individuals were more susceptible than the majority, and their growth was obviously inhibited.

Keyword(s): air pollution, oxidant.